on a Comet GL-RM1, running FW 1.8.0release3
tailscale does not respond to requests sent via the node’s assigned IPv6 tailnet address
upon inspection:
“ifconfig tailscale0” shows only the link local inet6 address assigned to the interface:
tailscale0 Link encap:UNSPEC HWaddr 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00
inet addr:100.65.120.91 P-t-P:100.65.120.91 Mask:255.255.255.255
inet6 addr: fe80::b787:96fc:6a2d:56a1/64 Scope:Link
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1280 Metric:1
RX packets:23 errors:0 dropped:0 overruns:0 frame:0
TX packets:17 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:1638 (1.5 KiB) TX bytes:1964 (1.9 KiB)
and “tailscale netcheck” shows that it indeed did not assign an address:
Report:
* Time: 2026-02-04T05:23:49.742153373Z
* UDP: true
* IPv4: yes, 71.68.32.131:44651
* IPv6: no, but OS has support
after looking at the tailscale/tailscaled code, i think this is due to the fact that it’s failing to run the ip6tables binary when it’s doing its initial checks to make sure it can set up stateful filtering.
when attempting to run “ip6tables -S” which invokes the xtables-multi binary, we can see that this check (which the tailscale binary does to see if ip6tables is working) indeed returns a failed rc:
[root@patrick-kvm:/sys/module]# ip6tables -S
modprobe: can't change directory to '/lib/modules': No such file or directory
ip6tables v1.6.1: can't initialize ip6tables table `filter': Table does not exist (do you need to insmod?)
Perhaps ip6tables or your kernel needs to be upgraded.
[root@patrick-kvm:/sys/module]# echo $?
3
i can’t have IPv4 enabled on my tailnet due to conflicts with CGNAT, so i am completely unable to access my KVMs via tailscale until this is fixed.