Frequent DHCP renewals

[paulwithonep]

I've been trying to track down an issue with opnsense 24.1.2 and my WAN connection dropping, and I noticed in the logs that dhclient is renewing frequently, about every 2-3 minutes. I enabled IPv6 info logging so it's a little bit more noisy than usual. I am unsure what to check next. Any ideas? Thanks in advance.

2024-03-03T08:54:30-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)   
2024-03-03T08:53:32-07:00   Notice   dhclient   dhclient-script: Creating resolv.conf   
2024-03-03T08:53:32-07:00   Notice   dhclient   dhclient-script: Reason RENEW on igc3 executing   
2024-03-03T08:53:24-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)   
2024-03-03T08:52:06-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)   
2024-03-03T08:51:07-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   got an expected reply, sleeping.   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   removing an event on igc3, state=RENEW   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   script "/var/etc/dhcp6c_wan_script.sh" terminated   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   dhcp6c_script: RENEW on igc3 executing   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   executes /var/etc/dhcp6c_wan_script.sh   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   update a prefix {redacted}::/56 pltime=600, vltime=1200   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   update an IA: PD-2   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   nameserver[1] {redacted}   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   nameserver[0] {redacted}   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   get DHCP option DNS, len 32   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   IA_PD prefix: {redacted}::/56 pltime=600 vltime=1200   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   get DHCP option IA_PD prefix, len 25   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   IA_PD: ID=2, T1=300, T2=480   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   get DHCP option IA_PD, len 41   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   DUID: {redacted}   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   get DHCP option server ID, len 10   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   DUID: {redacted}
2024-03-03T08:51:05-07:00   Notice   dhcp6c   get DHCP option client ID, len 14   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   receive reply from {redacted}::1 on igc3   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   send renew to ff02::1:2%igc3   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   set IA_PD   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   set IA_PD prefix   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   set option request (len 4)   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   set elapsed time (len 2)   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   set server ID (len 10)   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   set client ID (len 14)   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   a new XID (7d9492) is generated   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   reset a timer on igc3, state=RENEW, timeo=0, retrans=9384   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   IA timeout for PD-2, state=ACTIVE   
2024-03-03T08:51:02-07:00   Notice   dhclient   dhclient-script: Creating resolv.conf   
2024-03-03T08:51:02-07:00   Notice   dhclient   dhclient-script: Reason RENEW on igc3 executing   
2024-03-03T08:50:14-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)   
2024-03-03T08:48:32-07:00   Notice   dhclient   dhclient-script: Creating resolv.conf   
2024-03-03T08:48:32-07:00   Notice   dhclient   dhclient-script: Reason RENEW on igc3 executing   
2024-03-03T08:48:23-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)   
2024-03-03T08:46:39-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)   
2024-03-03T08:46:07-07:00   Notice   opnsense   /usr/local/etc/rc.newwanipv6: No IP change detected (current: {redacted}, interface: wan)

... and it just repeats like this every few minutes.

[zan]

2024-03-03T08:51:05-07:00   Notice   dhcp6c   IA_PD prefix: {redacted}::/56 pltime=600 vltime=1200   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   get DHCP option IA_PD prefix, len 25   
2024-03-03T08:51:05-07:00   Notice   dhcp6c   IA_PD: ID=2, T1=300, T2=480   

Your log shows dhcp6c requested default lease time of 300s and max time of 480s. Your ISP granted you a preferred lifetime of 600s and max lifetime of 1200s. Those values are too short that's why it kept renewing.

Are you using a custom dhcp6c.conf? If not, can you post the content of your /var/etc/dhcp6c_wan.conf?

[paulwithonep]

Thanks for the reply. I am not using a custom dhcp6c.conf to my knowledge. Here is the conf file:

interface igc3 {
  send ia-na 2; # request stateful address
  send ia-pd 2; # request prefix delegation
  request domain-name-servers;
  request domain-name;
  script "/var/etc/dhcp6c_wan_script.sh"; # we'd like some nameservers please
};
id-assoc na 2 { };
id-assoc pd 2 {
  prefix ::/56 infinity;
  prefix-interface igc0 {
    sla-id 0;
    sla-len 8;
  };
};

[meyergru]

Is there any special reason why you use IAID 2 instead of 0?

Maybe the offered lease time is too short because of this. Look at the "advanced" tab of the options, you can see and modify the IAID there.

[zzup]

I just looked at my logs as i have been having disconnects and reboots a couple times a day.  I found that my DHCP is renewing every 2 hours from my isp and that is when the issue happens.  Similar issue to yours.  I do not have any custom setting for lease for my wan. 

[zan]

Your dhcpc6.conf seems normal. Could be your ISP side also possible that your ISP expects real values for both preferred life time & valid lifetime during request instead of 'infinity'.
Can you try to specify both values on dhcp6 config?

One way to do it is to copy your /var/etc/dhcpc6.conf to /var/etc/mydhcp6.conf, edit mydhcp6.conf and replace the line

Code: [Select]

prefix ::/56 infinity; with

Code: [Select]

prefix ::/56 86400 172800;
Then put /var/etc/mydhcp6.conf on your WAN>Config File Override>Configuration File Override field and reboot.

If it still doesn't get your a longer lease then I suggest you check with your ISP.

[Fuggin]

I have the same problem with this but I am just using IPv4. My WAN drops out completely and I have to hard reboot the NUC. I get the same DHCP renewals on my logs but I am not sure it is the source of my WAN dropping out:

Code: [Select]

2024-03-11T16:13:41-04:00 Notice dhclient dhclient-script: Creating resolv.conf
2024-03-11T16:13:41-04:00 Notice dhclient dhclient-script: Reason RENEW on vtnet0 executing
2024-03-11T16:13:41-04:00 Error dhclient unknown dhcp option value 0x7d