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English Forums => General Discussion => Topic started by: ProximusAl on March 20, 2026, 12:23:21 PM

Title: [SOLVED] IPv6 Log Entry Question (dhcp6c)
Post by: ProximusAl on March 20, 2026, 12:23:21 PM
Hi All,

Quick question for any experts out there.

I get IPv6 over PPPoE and only set the following on the WAN interface:

IPv6 Configuration Type: DHCPv6
Prefix Delegation Size: 48

Everything else is unticked, including "Send prefix hint" and "Request prefix only"

IPv6 actually works perfectly well, with a /64 on the WAN, and a chunk of my /48 on the LAN(/64) but I get a lot of these entries in the log.

2026-03-20T11:03:54    Notice    dhcp6c    advertise contains no address/prefix
2026-03-20T11:03:54    Notice    dhcp6c    Sending Solicit on pppoe0

Is there anything I can do to suppress "advertise contains no address/prefix" or is this normal?

Thanks...
Title: Re: IPv6 Log Entry Question (dhcp6c)
Post by: franco on March 20, 2026, 12:28:25 PM
It's somewhat important because whatever dhcp6c tried to do failed. If you want to look closer use debug logging for IPv6. If not please ignore.


Cheers,
Franco
Title: Re: IPv6 Log Entry Question (dhcp6c)
Post by: ProximusAl on March 20, 2026, 01:52:26 PM
Thanks Franco,

Seems to be on the hour-ish

2026-03-20T12:05:16Noticedhcp6cadvertise contains no address/prefix
2026-03-20T12:05:16Noticedhcp6cSending Solicit on pppoe0
2026-03-20T11:03:54Noticedhcp6cadvertise contains no address/prefix
2026-03-20T11:03:54Noticedhcp6cSending Solicit on pppoe0
2026-03-20T10:03:11Noticedhcp6cadvertise contains no address/prefix
2026-03-20T10:03:11Noticedhcp6cSending Solicit on pppoe0
2026-03-20T09:05:49Noticedhcp6cadvertise contains no address/prefix
2026-03-20T09:05:49Noticedhcp6cSending Solicit on pppoe0
2026-03-20T08:08:39Noticedhcp6cadvertise contains no address/prefix
2026-03-20T08:08:39Noticedhcp6cSending Solicit on pppoe0
2026-03-20T07:09:46Noticedhcp6cadvertise contains no address/prefix
2026-03-20T07:09:45Noticedhcp6cSending Solicit on pppoe0

How do I enable IPv6 debug?
Title: Re: IPv6 Log Entry Question (dhcp6c)
Post by: franco on March 20, 2026, 02:18:30 PM
Interfaces: Settings: Debug logging

Needs a reboot.


Cheers,
Franco
Title: Re: IPv6 Log Entry Question (dhcp6c)
Post by: ProximusAl on March 20, 2026, 02:52:54 PM
I've Xed out some bits:

2026-03-20T13:50:26Noticedhcp6cadvertise contains no address/prefix
2026-03-20T13:50:26Noticedhcp6cserver ID: 00:XX:00:00:XX:XX:XX:XX:XX:37:66:3a:66:38:3a:37:34:3a:62:63:XX:XX:XX:00:00:00, pref=-1
2026-03-20T13:50:26Noticedhcp6cstatus code: no addresses
2026-03-20T13:50:26Noticedhcp6cget DHCP option status code, len 43
2026-03-20T13:50:26Noticedhcp6cIA_NA: ID=5, T1=0, T2=0
2026-03-20T13:50:26Noticedhcp6cget DHCP option identity association, len 59
2026-03-20T13:50:26Noticedhcp6cDUID: 00:XX:00:00:XX:XX:XX:XX:3a:37:66:3a:66:38:3a:37:34:3a:62:63:XX:XX:XX:00:00:00
2026-03-20T13:50:26Noticedhcp6cget DHCP option server ID, len 26
2026-03-20T13:50:26Noticedhcp6cDUID: 00:0X:00:0X:XX:dc:XX:1d:f4:90:XX:01:cb:XX
2026-03-20T13:50:26Noticedhcp6cget DHCP option client ID, len 14
2026-03-20T13:50:26Noticedhcp6creceive advertise from fe80::200:ff:fe00:0%pppoe0 on pppoe0
2026-03-20T13:50:26Noticedhcp6creset a timer on pppoe0, state=SOLICIT, timeo=5, retrans=35593
2026-03-20T13:50:26Noticedhcp6csend solicit to ff02::1:2%pppoe0
2026-03-20T13:50:26Noticedhcp6cset elapsed time (len 2)
2026-03-20T13:50:26Noticedhcp6cset identity association
2026-03-20T13:50:26Noticedhcp6cset client ID (len 14)
2026-03-20T13:50:26Noticedhcp6cSending Solicit on pppoe0
Title: Re: IPv6 Log Entry Question (dhcp6c)
Post by: ProximusAl on March 20, 2026, 03:17:29 PM
If I "Request Prefix Only" the problem goes away......

So that is what I shall do, even though the ISP gives me a /64 for WAN.

This is ZEN UK.

EDIT: Looks like ZEN give the WAN IP via SLAAC, not IA_NA, and thats where the issue was.
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