IPV6 problem - DHCP6c file configuration issue?

koyaan134 · Jun 9, 2025, 3:01 AM

Hi all!

Have been troubleshooting some ipv6 problems on my pfsense box. I'm a newbie so bear with me.

Basically I know my prefix and I'm getting it from spectrum but it's not being taken up.

In the logs I have:

lstat failed: No such file or directory

script "/var/etc/dhcp6c_wan_script.sh" cannot be executed safely

I've been doing some chatgpt troubleshooting - and it suspects that this is the problem:

dhcp6c refuses to run a helper script unless it is exactly 0700

And my output is:

-rwxr-xr-x 1 root wheel 443 Jun 8 21:52 /var/etc/dhcp6c_wan_script.sh

Is it on the right track, or am I totally off base? Happy to provide more context if helpful. And why would this misconfiguration have occurred? This is mostly a fresh/vanilla install. Thanks!

Gertjan · Jun 9, 2025, 5:37 AM

@koyaan134

pfSense version ?

@koyaan134 said in IPV6 problem - DHCP6c file configuration issue?:

dhcp6c refuses to run a helper script unless it is exactly 0700

FreeBSD dhcp6c config file info. I don't see this 'owner only' 'rwx' flags only limit.

My "/var/etc/dhcp6c_wan_script.sh" file has the same owner and rights as yours :

[25.03-BETA][root@pfSense.bhf.tld]/var/etc: ll dhcp6c_wan_script.sh
-rwxr-xr-x  1 root wheel 441 Jun  7 13:31 dhcp6c_wan_script.sh*

I presume pfSense 2.8.0 and 25.03 are identical.

koyaan134 · Jun 9, 2025, 8:48 AM

@Gertjan 2.8.0! But it had broken (I had it working for about a year) before I upgraded pfsense last week.

Gertjan · Jun 9, 2025, 9:46 AM

@koyaan134

You've tried 0700 ?

[25.03-BETA][root@pfSense.brit-hotel-fumel.net]/root: ps aux | grep 'dhcp6c'
root    78873   0.0  0.1  14128   2888  -  Is   Sat13       0:00.51 /usr/local/sbin/dhcp6c -d -c /var/etc/dhcp6c.conf -p /var/run/dhcp6c.pid ix3

so the dhcp6c service runs as root.
The file(s) it uses are owned by root, it's marked as it should : shell script so +x.

I still can't figure out why this is your issue :

@koyaan134 said in IPV6 problem - DHCP6c file configuration issue?:

lstat failed: No such file or directory

script "/var/etc/dhcp6c_wan_script.sh" cannot be executed safely

because IPv6 WAN isn't something special anymore for a long time, so your files are the same as all the other '2.8.0' users, and I haven't seen a massive "2.8.0 IPv6 WAN DHCP6 is broken" forum posts.

You're using the standard dhcp6c config file, or did you create on yourself ?

koyaan134 · Jun 11, 2025, 3:58 PM

@Gertjan Standard file! No special config apart from messing around with the prefix hint. I was a bit nervous to make changes to the dhcp6c service based on chatgpt alone.

Weird thing - ipv6 started randomly working overnight for about a day yesterday, but is back down this morning, without me doing anything.

here are some sanitized logs for curiousity's sake:

Jun 11 00:42:46 kea2fib6 <PID> Error decoding response from Kea control socket: /var/run/kea6-ctrl-socket
Jun 11 00:42:46 kea2unbound <PID> Unbound lease include is missing or inconsistent: /var/unbound/leases/leases6.conf
Jun 11 00:42:46 kea2unbound <PID> Include updated: /var/unbound/leases/leases6.conf (<hash>)
Jun 11 00:42:46 kea2unbound <PID> Unbound reloaded: /var/unbound/unbound.conf
Jun 11 00:42:46 dhclient <PID> DHCPREQUEST on igb0 to <IPv4-priv> port 67
Jun 11 00:42:57 dhclient <PID> DHCPREQUEST on igb0 to <IPv4-bcast> port 67
Jun 11 00:42:59 dhclient <PID> EXPIRE
Jun 11 00:42:59 dhclient <PID> Deleting old routes
Jun 11 00:42:59 dhclient <PID> PREINIT
Jun 11 00:42:59 dhclient <PID> DHCPDISCOVER on igb0 to <IPv4-bcast> port 67 interval 2
Jun 11 00:42:59 dhclient <PID> DHCPOFFER from <IPv4-srv>
Jun 11 00:42:59 dhclient <PID> ARPSEND
Jun 11 00:42:59 dhclient <PID> ARPCHECK
Jun 11 00:42:59 dhclient <PID> DHCPREQUEST on igb0 to <IPv4-bcast> port 67
Jun 11 00:43:00 dhclient <PID> DHCPACK from <IPv4-srv>
Jun 11 00:43:00 dhclient <PID> BOUND
Jun 11 00:43:00 dhclient <PID> New IP Address (igb0): <IPv4-wan>
Jun 11 00:43:00 dhclient <PID> New Routers (igb0): <IPv4-gw>
Jun 11 00:43:00 dhclient <PID> Creating resolv.conf
Jun 11 00:43:00 dhclient <PID> bound to <IPv4-wan> -- renewal in 28226 seconds
Jun 11 00:43:06 dhcp6c <PID> restarting
Jun 11 00:43:06 dhcp6c <PID> remove an address <IA-NA> on igb0
Jun 11 00:43:06 dhcp6c <PID> remove an address <IA-PD-LAN> on igb1
Jun 11 00:43:06 dhcp6c <PID> Sending Solicit / Request
Jun 11 00:43:06 dhcp6c <PID> add an address <IA-PD-LAN> on igb1
Jun 11 00:43:06 dhcp6c <PID> add an address <IA-NA> on igb0
Jun 11 00:43:12 dhcp6c <PID> Sending Release (repeats) … no responses were received
...
Jun 11 01:44:23 kea-dhcp6 <PID> DHCP6_PACKET_SEND_FAIL duid=<DUID-xxxx> … sendmsg() error: Permission denied
Jun 11 02:35:36 kea-dhcp6 <PID> ALLOC_ENGINE_V6_ALLOC_FAIL_NO_POOLS subnet <IA-PD-LAN>, subnet-id 1
Jun 11 03:53:05 kea-dhcp6 <PID> DHCP6_PACKET_SEND_FAIL duid=<DUID-xxxx> … Permission denied
Jun 11 07:04:11 kea-dhcp6 <PID> DHCP6_PACKET_SEND_FAIL duid=<DUID-xxxx> … Permission denied
Jun 11 08:33:25 dhclient <PID> DHCPREQUEST on igb0 to <IPv4-srv2> port 67
Jun 11 08:33:25 dhclient <PID> DHCPACK from <IPv4-srv>
Jun 11 08:33:25 dhclient <PID> RENEW — bound to <IPv4-wan>
Jun 11 10:05:18 kea-dhcp6 <PID> DHCP6_PACKET_SEND_FAIL duid=<DUID-xxxx> … Permission denied

koyaan134 · Jun 11, 2025, 5:00 PM

@koyaan134 And just to be clear - as soon as I take a look at it again, it's back up.