picky DHCP on WAN

Started by TheSHAD0W, June 11, 2026, 09:44:28 PM

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June 11, 2026, 09:44:28 PM
I've been having issues with connecting to my DSL provider's service on opnsense. It will occasionally connect but not for longer than a few hours and it may take hours to reconnect. I've tested with kali, mint and win10 and all three are able to connect, though it does seem to take a bit longer than it ought to. Some options taken from the gemini llm improved the situation a bit but not acceptably; the connection would still tend to drop after a while. (It also seems the router doesn't attempt to renew the lease until right at the very end of the lease term.) It looks to me like the provider is dropping most of the packets it receives from opnsense, but is more permissive from other sources. I've replacing the ethernet adapter too. (Both are intel i350 type.)

Quoteroot@router:/var/etc # cat /var/etc/dhclient.igb2.conf
interface "igb2" {
  timeout 60;
  retry 15;
  select-timeout 0;
  initial-interval 1;
  script "/usr/local/opnsense/scripts/interfaces/dhclient-script";
  supersede interface-mtu 0;
}

QuoteFlags   up
broadcast
running
promisc
simplex
multicast
lower_up
Capabilities   rxcsum
txcsum
vlan_mtu
vlan_hwtagging
jumbo_mtu
vlan_hwcsum
tso4
tso6
lro
wol_ucast
wol_mcast
wol_magic
vlan_hwfilter
vlan_hwtso
netmap
rxcsum_ipv6
txcsum_ipv6
hwstats
mextpg
Options   vlan_mtu
vlan_hwtagging
jumbo_mtu
vlan_hwcsum
wol_magic
vlan_hwfilter
vlan_hwtso
hwstats
mextpg
MAC Address   80:61:5f:08:00:74 - Beijing Sinead Technology Co.
Ltd.
Supported Media   autoselect
1000baseT
1000baseT full-duplex
100baseTX full-duplex
100baseTX
10baseT/UTP full-duplex
10baseT/UTP
Physical   true
Device   igb2
mtu   1500
macaddr_hw   80:61:5f:08:00:74
Media   100baseTX <full-duplex>
Media (Raw)   Ethernet autoselect (100baseTX <full-duplex>)
Status   up
nd6   
flags
performnud
ifdisabled
auto_linklocal
Identifier   opt7
Description   WANdsl
Enabled   true
Link Type   dhcp
addr4   
addr6   
VLAN Tag   
Gateways   
Driver   igb2
Index   7
Promiscuous Listeners   1
Send Queue Length   0
Send Queue Max Length   50
Send Queue Drops   0
Type   Ethernet
Address Length   6
Header Length   18
Link State   2
vhid   0
Data Length   152
Metric   0
Line Rate   100.00 Mbit/s
Packets Received   3320
Input Errors   0
Packets Transmitted   90121
Output Errors   0
Collisions   0
Bytes Received   318664
Bytes Transmitted   10446593
Multicasts Received   426
Multicasts Transmitted   0
Input Queue Drops   0
Packets for Unknown Protocol   0
Hardware Offload Capabilities   0x0
Uptime at Attach or Statistics Reset   1

example of a successful handshake:
Quote13:59:59.313540 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0x29715326, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:00:12.315311 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0x29715326, secs 13, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:00:28.356093 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0x29715326, secs 29, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:00:38.407528 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0x29715326, secs 39, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:00:51.408343 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0x29715326, secs 52, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:01:01.459540 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0xddf175e3, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:01:01.654312 08:96:ad:5a:db:c1 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 355: (tos 0xc0, ttl 30, id 48761, offset 0, flags [none], proto UDP (17), length 341)
    104.193.102.1.67 > 255.255.255.255.68: [udp sum ok] BOOTP/DHCP, Reply, length 313, xid 0xddf175e3, Flags [none] (0x0000)
     Your-IP 104.193.102.85
     Gateway-IP 104.193.102.1
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Offer
       Subnet-Mask (1), length 4: 255.255.255.0
       Default-Gateway (3), length 4: 104.193.102.1
       Domain-Name-Server (6), length 12: 199.27.156.34,199.27.156.35,167.254.227.7
       Hostname (12), length 6: "router"
       Domain-Name (15), length 12: "dellcity.com"
       Lease-Time (51), length 4: 3600
       Server-ID (54), length 4: 199.27.156.55
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
14:01:02.669840 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0xddf175e3, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Request
       Server-ID (54), length 4: 199.27.156.55
       Requested-IP (50), length 4: 104.193.102.85
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:01:11.679729 80:61:5f:08:00:74 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 342: (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 80:61:5f:08:00:74, length 300, xid 0xddf175e3, Flags [none] (0x0000)
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Request
       Server-ID (54), length 4: 199.27.156.55
       Requested-IP (50), length 4: 104.193.102.85
       Client-ID (61), length 7: ether 80:61:5f:08:00:74
       Hostname (12), length 6: "router"
       Parameter-Request (55), length 10:
         Subnet-Mask (1), BR (28), Time-Zone (2), Classless-Static-Route (121)
         Default-Gateway (3), Domain-Name (15), Domain-Name-Server (6), Hostname (12)
         Unknown (119), MTU (26)
14:01:11.866296 08:96:ad:5a:db:c1 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 355: (tos 0xc0, ttl 30, id 56185, offset 0, flags [none], proto UDP (17), length 341)
    104.193.102.1.67 > 255.255.255.255.68: [udp sum ok] BOOTP/DHCP, Reply, length 313, xid 0xddf175e3, Flags [none] (0x0000)
     Your-IP 104.193.102.85
     Gateway-IP 104.193.102.1
     Client-Ethernet-Address 80:61:5f:08:00:74
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: ACK
       Subnet-Mask (1), length 4: 255.255.255.0
       Default-Gateway (3), length 4: 104.193.102.1
       Domain-Name-Server (6), length 12: 199.27.156.34,199.27.156.35,167.254.227.7
       Hostname (12), length 6: "router"
       Domain-Name (15), length 12: "dellcity.com"
       Lease-Time (51), length 4: 3600
       Server-ID (54), length 4: 199.27.156.55
       Client-ID (61), length 7: ether 80:61:5f:08:00:74

Example of handshake from other device:
Quote13:06:35.855113 08:8f:c3:6d:33:fd > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 333: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 319)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 08:8f:c3:6d:33:fd, length 291, xid 0xa3745acd, secs 1, Flags [none] (0x0000)
     Client-Ethernet-Address 08:8f:c3:6d:33:fd
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 08:8f:c3:6d:33:fd
       Parameter-Request (55), length 17:
         Subnet-Mask (1), Time-Zone (2), Domain-Name-Server (6), Hostname (12)
         Domain-Name (15), MTU (26), BR (28), Classless-Static-Route (121)
         Default-Gateway (3), Static-Route (33), YD (40), YS (41)
         NTP (42), Unknown (119), Classless-Static-Route-Microsoft (249), Unknown (252)
         RP (17)
       MSZ (57), length 2: 576
       Requested-IP (50), length 4: 104.193.102.50
       Hostname (12), length 7: "misaka4"
13:06:38.612918 08:8f:c3:6d:33:fd > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 333: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 319)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 08:8f:c3:6d:33:fd, length 291, xid 0x843f0ebf, secs 2, Flags [none] (0x0000)
     Client-Ethernet-Address 08:8f:c3:6d:33:fd
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Discover
       Client-ID (61), length 7: ether 08:8f:c3:6d:33:fd
       Parameter-Request (55), length 17:
         Subnet-Mask (1), Time-Zone (2), Domain-Name-Server (6), Hostname (12)
         Domain-Name (15), MTU (26), BR (28), Classless-Static-Route (121)
         Default-Gateway (3), Static-Route (33), YD (40), YS (41)
         NTP (42), Unknown (119), Classless-Static-Route-Microsoft (249), Unknown (252)
         RP (17)
       MSZ (57), length 2: 576
       Requested-IP (50), length 4: 104.193.102.50
       Hostname (12), length 7: "misaka4"
13:06:38.751299 08:96:ad:5a:db:c1 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 356: (tos 0xc0, ttl 30, id 26121, offset 0, flags [none], proto UDP (17), length 342)
    104.193.102.1.67 > 255.255.255.255.68: [udp sum ok] BOOTP/DHCP, Reply, length 314, xid 0x843f0ebf, Flags [none] (0x0000)
     Your-IP 104.193.102.50
     Gateway-IP 104.193.102.1
     Client-Ethernet-Address 08:8f:c3:6d:33:fd
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Offer
       Subnet-Mask (1), length 4: 255.255.255.0
       Default-Gateway (3), length 4: 104.193.102.1
       Domain-Name-Server (6), length 12: 199.27.156.34,199.27.156.35,167.254.227.7
       Hostname (12), length 7: "misaka4"
       Domain-Name (15), length 12: "dellcity.com"
       Lease-Time (51), length 4: 3600
       Server-ID (54), length 4: 199.27.156.55
       Client-ID (61), length 7: ether 08:8f:c3:6d:33:fd
13:06:38.751530 08:8f:c3:6d:33:fd > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 339: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 325)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 08:8f:c3:6d:33:fd, length 297, xid 0x843f0ebf, secs 2, Flags [none] (0x0000)
     Client-Ethernet-Address 08:8f:c3:6d:33:fd
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Request
       Client-ID (61), length 7: ether 08:8f:c3:6d:33:fd
       Parameter-Request (55), length 17:
         Subnet-Mask (1), Time-Zone (2), Domain-Name-Server (6), Hostname (12)
         Domain-Name (15), MTU (26), BR (28), Classless-Static-Route (121)
         Default-Gateway (3), Static-Route (33), YD (40), YS (41)
         NTP (42), Unknown (119), Classless-Static-Route-Microsoft (249), Unknown (252)
         RP (17)
       MSZ (57), length 2: 576
       Requested-IP (50), length 4: 104.193.102.50
       Server-ID (54), length 4: 199.27.156.55
       Hostname (12), length 7: "misaka4"
13:06:43.051749 08:8f:c3:6d:33:fd > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 339: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 325)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 08:8f:c3:6d:33:fd, length 297, xid 0x843f0ebf, secs 2, Flags [none] (0x0000)
     Client-Ethernet-Address 08:8f:c3:6d:33:fd
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Request
       Client-ID (61), length 7: ether 08:8f:c3:6d:33:fd
       Parameter-Request (55), length 17:
         Subnet-Mask (1), Time-Zone (2), Domain-Name-Server (6), Hostname (12)
         Domain-Name (15), MTU (26), BR (28), Classless-Static-Route (121)
         Default-Gateway (3), Static-Route (33), YD (40), YS (41)
         NTP (42), Unknown (119), Classless-Static-Route-Microsoft (249), Unknown (252)
         RP (17)
       MSZ (57), length 2: 576
       Requested-IP (50), length 4: 104.193.102.50
       Server-ID (54), length 4: 199.27.156.55
       Hostname (12), length 7: "misaka4"
13:06:47.497671 08:8f:c3:6d:33:fd > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 339: (tos 0x0, ttl 64, id 0, offset 0, flags [DF], proto UDP (17), length 325)
    0.0.0.0.68 > 255.255.255.255.67: [udp sum ok] BOOTP/DHCP, Request from 08:8f:c3:6d:33:fd, length 297, xid 0x843f0ebf, secs 2, Flags [none] (0x0000)
     Client-Ethernet-Address 08:8f:c3:6d:33:fd
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: Request
       Client-ID (61), length 7: ether 08:8f:c3:6d:33:fd
       Parameter-Request (55), length 17:
         Subnet-Mask (1), Time-Zone (2), Domain-Name-Server (6), Hostname (12)
         Domain-Name (15), MTU (26), BR (28), Classless-Static-Route (121)
         Default-Gateway (3), Static-Route (33), YD (40), YS (41)
         NTP (42), Unknown (119), Classless-Static-Route-Microsoft (249), Unknown (252)
         RP (17)
       MSZ (57), length 2: 576
       Requested-IP (50), length 4: 104.193.102.50
       Server-ID (54), length 4: 199.27.156.55
       Hostname (12), length 7: "misaka4"
13:06:47.691162 08:96:ad:5a:db:c1 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0x0800), length 356: (tos 0xc0, ttl 30, id 32265, offset 0, flags [none], proto UDP (17), length 342)
    104.193.102.1.67 > 255.255.255.255.68: [udp sum ok] BOOTP/DHCP, Reply, length 314, xid 0x843f0ebf, Flags [none] (0x0000)
     Your-IP 104.193.102.50
     Gateway-IP 104.193.102.1
     Client-Ethernet-Address 08:8f:c3:6d:33:fd
     Vendor-rfc1048 Extensions
       Magic Cookie 0x63825363
       DHCP-Message (53), length 1: ACK
       Subnet-Mask (1), length 4: 255.255.255.0
       Default-Gateway (3), length 4: 104.193.102.1
       Domain-Name-Server (6), length 12: 199.27.156.34,199.27.156.35,167.254.227.7
       Hostname (12), length 7: "misaka4"
       Domain-Name (15), length 12: "dellcity.com"
       Lease-Time (51), length 4: 3600
       Server-ID (54), length 4: 199.27.156.55
       Client-ID (61), length 7: ether 08:8f:c3:6d:33:fd
June 11, 2026, 10:18:52 PM #1
Also for reference: Here are the settings gemini recommended:
Quoteroot@router:/var/etc # cat dhclient.igb2.conf
interface "igb2" {
  # timing values
  backoff-cutoff 10;
  initial-interval 10;
  reboot 30;
  retry 5;
  select-timeout 1;
  timeout 60;
  # custom options
  require dhcp-server-identifier;
  always-broadcast true;
  supersede dhcp-max-message-size 576;
  supersede dhcp-parameter-request-list 1,28,2,121,3,15,6,12,119,26,57;
  # standard settings
  script "/usr/local/opnsense/scripts/interfaces/dhclient-script";
  supersede interface-mtu 0;
}

Also got a *very* delayed DHCP ACK while testing these settings, which was interesting.
June 15, 2026, 07:03:22 PM #2
No change in behavior after upgrade to 26.1.10.
June 16, 2026, 10:03:49 AM #3
DHCP lease renewal is normally (per standard) attempted when half of the lease time remains. That's very well established, and generally stable.

There was a similar-ish sounding case recently, where the OP was convinced that DHCP wasn't doing what it's supposed to, but it actually turned out to be an issue with the ISP's hardware upstream: https://forum.opnsense.org/index.php?topic=51994.0
June 17, 2026, 05:16:07 PM #4
Quote from: dseven on June 16, 2026, 10:03:49 AMDHCP lease renewal is normally (per standard) attempted when half of the lease time remains. That's very well established, and generally stable.

I haven't been seeing opnsense do that though. It seems to wait until the 85% mark before attempting renewal.

Quote from: dseven on June 16, 2026, 10:03:49 AMThere was a similar-ish sounding case recently, where the OP was convinced that DHCP wasn't doing what it's supposed to, but it actually turned out to be an issue with the ISP's hardware upstream: https://forum.opnsense.org/index.php?topic=51994.0

Thanks for the reference. I'm pretty sure my ISP's hardware *is* an issue, yes. Thing is, as I said, other devices and OSes are able to do a much better job at connecting and keeping the lease up, and there's no reason for opnsense to be more fragile.
June 18, 2026, 04:20:55 AM #5 Last Edit: June 18, 2026, 04:22:40 AM by lmoore
Quote from: TheSHAD0W on June 17, 2026, 05:16:07 PMThing is, as I said, other devices and OSes are able to do a much better job at connecting and keeping the lease up, and there's no reason for opnsense to be more fragile.

Looking at the requests the notable differences are;

  • OPNsense TOS field is set to 0x10 whereas in the other it is 0x0
  • The initial time interval for OPNsense re-transismission is 13 seconds, where as the other is 3 seconds

I have experienced similar issues a long time ago but I think they were ISP related and may have been when the connection to the primary server failed, hence it was directed to their back-up system.

I have a minimal DHCP client configuration on my firewall and rely on internal DNS servers.


This is my dhclient configuration file.
Code Select
interface "re0" {
  # timing values
  # custom options
  request subnet-mask, routers;
  require subnet-mask, routers;
  send dhcp-lease-time 3600;
  # standard settings
  script "/usr/local/opnsense/scripts/interfaces/dhclient-script";
  supersede interface-mtu 0;
}
Looking at the DHCP request to my ISP on OPNsense 26.1.10, the first two requests go within the same second and the response is immediate.

Quotetcpdump: listening on re0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
09:03:41.409243 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xa7f96e94, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Requested-IP (50), length 4: aaa.bbb.ccc.ddd
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
09:03:41.409292 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xa7f96e94, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Requested-IP (50), length 4: aaa.bbb.ccc.ddd
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
June 18, 2026, 12:46:43 PM #6
Quote from: TheSHAD0W on June 17, 2026, 05:16:07 PM
Quote from: dseven on June 16, 2026, 10:03:49 AMDHCP lease renewal is normally (per standard) attempted when half of the lease time remains. That's very well established, and generally stable.

I haven't been seeing opnsense do that though. It seems to wait until the 85% mark before attempting renewal.

opnsense just uses the standard dhclient - nothing special as far as lease renewal goes (AFAIK).

How are you observing this "85% mark"? What does /var/db/dhclient.leases.igb2 look like?
June 19, 2026, 03:16:42 AM #7
The dhclient.leases.igb2 looks as expected. I was looking at packets through tcpdump and did not see any request packets at all at the 1800 second mark, none until it was nearly expired.
June 19, 2026, 06:54:51 AM #8 Last Edit: June 19, 2026, 07:04:11 AM by lmoore
Quote from: TheSHAD0W on June 19, 2026, 03:16:42 AMI was looking at packets through tcpdump and did not see any request packets at all at the 1800 second mark, none until it was nearly expired.

That is odd as it is the DHCP client which performs the renewal and the lease time you received from the DHCP server was 3600 seconds.

With the other OS's you tested, did they drop or fail to renew their connections after a period of time too?

If your DHCP client isn't attempting to renew at around the 50% mark, OPNsense is somehow using a different lease renew time, and based upon 85% of 3600, this would be a setting of around 3060 seconds, or 51 minutes.

What happens if you adjust your DHCP settings so the subsequent DHCP Discover request goes at 6 seconds after the first?

Can you verify your are not blocking connections to the IP address listed in the Server-ID field, i.e. 199.27.156.55.
I don't see any Server-IP fields in the captures you've shown.


Yesterday I cleared the DHCP lease file and re-applied settings to the WAN interface.

With the settings I use, the second DHCP Discover goes out 6-seconds later and promptly receives the request.

I also kicked off tcpdump to watch the DHCP lease renewal and they are happening at the 50% mark, i.e., 1800 seconds.

My captures reveals two DHCP servers, most probably Relays, responding to the initial DHCP Discover request. After that it is renewing with the DHCP server defined in the Server-ID field.

This is my capture command - via SSH: tcpdump -pvni re0 'proto udp and port (67 or 68)'

For those who may be wondering, I've been using the Realtek NIC in a Draytek VigorNIC 132 modem with OPNsense and without issues ever since January 2021. Initially for many, many, months without the Realtek kernel module. It was after reading many messages advising installing the non-FreeBSD driver that I installed it.

Code Select
DHCP Server 1 = a.a.a.a
DHCP Server 2 = b.b.b.b
Server-IP 1 = c.c.c.c
Server-IP 2 = d.d.d.d
Server-ID = e.e.e.e
My IP address = f.f.f.f
Default Gateway = g.g.g.g


tcpdump: listening on re0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
12:52:16.481293 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Discover
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
12:52:16.481345 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Discover
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
12:52:22.496067 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, secs 6, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Discover
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
12:52:22.496162 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, secs 6, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Discover
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
12:52:27.818108 IP (tos 0x0, ttl 255, id 39865, offset 0, flags [none], proto UDP (17), length 328)
    a.a.a.a.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, secs 6, Flags [none]
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Offer
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
12:52:27.818907 IP (tos 0x0, ttl 255, id 39867, offset 0, flags [none], proto UDP (17), length 328)
    b.b.b.b.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, secs 6, Flags [none]
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Offer
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
12:52:28.076789 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, secs 6, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Requested-IP (50), length 4: f.f.f.f
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
12:52:28.076883 IP (tos 0x10, ttl 128, id 0, offset 0, flags [none], proto UDP (17), length 328)
    0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, secs 6, Flags [none]
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Requested-IP (50), length 4: f.f.f.f
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
12:52:28.109575 IP (tos 0x0, ttl 255, id 39876, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, secs 6, Flags [none]
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
12:52:28.147722 IP (tos 0x0, ttl 255, id 39877, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, secs 6, Flags [none]
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g


tcpdump: listening on re0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
19:22:28.148922 IP (tos 0x10, ttl 128, id 37964, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
19:22:28.149004 IP (tos 0x10, ttl 128, id 37964, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
19:22:28.171188 IP (tos 0x0, ttl 255, id 62899, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
19:22:28.219356 IP (tos 0x0, ttl 255, id 62900, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
19:52:28.201780 IP (tos 0x10, ttl 128, id 4220, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
19:52:28.201865 IP (tos 0x10, ttl 128, id 4220, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
19:52:28.223429 IP (tos 0x0, ttl 255, id 19271, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
19:52:28.272798 IP (tos 0x0, ttl 255, id 19273, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
20:22:28.266868 IP (tos 0x10, ttl 128, id 65065, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
20:22:28.266990 IP (tos 0x10, ttl 128, id 65065, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
20:22:28.289581 IP (tos 0x0, ttl 255, id 41167, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
20:22:28.337901 IP (tos 0x0, ttl 255, id 41169, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
20:52:28.363349 IP (tos 0x10, ttl 128, id 61856, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
20:52:28.363427 IP (tos 0x10, ttl 128, id 61856, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
20:52:28.385334 IP (tos 0x0, ttl 255, id 63034, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
20:52:28.433614 IP (tos 0x0, ttl 255, id 63035, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
21:22:28.526671 IP (tos 0x10, ttl 128, id 47860, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
21:22:28.526779 IP (tos 0x10, ttl 128, id 47860, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
21:22:28.549280 IP (tos 0x0, ttl 255, id 19392, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
21:22:28.597992 IP (tos 0x0, ttl 255, id 19394, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
21:52:28.603988 IP (tos 0x10, ttl 128, id 227, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
21:52:28.604092 IP (tos 0x10, ttl 128, id 227, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
21:52:28.625739 IP (tos 0x0, ttl 255, id 41260, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
21:52:28.674379 IP (tos 0x0, ttl 255, id 41261, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
22:22:28.750381 IP (tos 0x10, ttl 128, id 28758, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
22:22:28.750493 IP (tos 0x10, ttl 128, id 28758, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
22:22:28.987440 IP (tos 0x0, ttl 255, id 63083, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
22:22:29.034725 IP (tos 0x0, ttl 255, id 63085, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
22:52:28.020620 IP (tos 0x10, ttl 128, id 63357, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
22:52:28.020665 IP (tos 0x10, ttl 128, id 63357, offset 0, flags [none], proto UDP (17), length 328)
    f.f.f.f.68 > e.e.e.e.67: BOOTP/DHCP, Request from 00:1d:aa:6b:89:ef, length 300, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: Request
            Lease-Time (51), length 4: 3600
            Client-ID (61), length 7: ether 00:1d:aa:6b:89:ef
            Hostname (12), length 6: "vpn-gw"
            Parameter-Request (55), length 2:
              Subnet-Mask (1), Default-Gateway (3)
22:52:28.167766 IP (tos 0x0, ttl 255, id 19369, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP c.c.c.c
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
22:52:28.220303 IP (tos 0x0, ttl 255, id 19370, offset 0, flags [none], proto UDP (17), length 328)
    e.e.e.e.67 > f.f.f.f.68: BOOTP/DHCP, Reply, length 300, hops 1, xid 0xb9c33b02, Flags [none]
          Client-IP f.f.f.f
          Your-IP f.f.f.f
          Server-IP d.d.d.d
          Client-Ethernet-Address 00:1d:aa:6b:89:ef
          Vendor-rfc1048 Extensions
            Magic Cookie 0x63825363
            DHCP-Message (53), length 1: ACK
            Server-ID (54), length 4: e.e.e.e
            Lease-Time (51), length 4: 3600
            Subnet-Mask (1), length 4: 255.255.224.0
            Default-Gateway (3), length 4: g.g.g.g
June 19, 2026, 02:29:55 PM #9
Quote from: TheSHAD0W on June 19, 2026, 03:16:42 AMThe dhclient.leases.igb2 looks as expected.

That doesn't tell me anything because I don't know what "expected" means to you!

It should show the "renew" and "expire" times for each lease, and the difference between them should be half of the lease duration. You should see a renewal request (packet) at the "renew" time.
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