I've had my tunnel up for a good while, but sometime in the last few months, I don't know when it started happening, but after my firewall as been up for a week, give or take 3 days, it's random, it will just stop passing traffic.
Interface is up, routes are up, I can ping the remote IPv4 and the local IPv6, but 100% packet loss over the IPv6. No changes to the firewall rules ( iptables ) or any config, it just starts dropping all packets. As if I'm blocking a keepalive protocol I can't find docs on. If I reboot my linux box, traffic resumes without issue. If I down the interface and restart IPTables, no go, still dead.
Here's my config:
iface he-ipv6 inet6 v4tunnel
# Bring up the actual tunnel
address 2001:470:39:57c::2
netmask 64
endpoint 184.105.250.46
#local `/usr/local/bin/GetExternalIP.sh`
local 209.182.74.168
ttl 255
gateway 2001:470:39:57c::1
post-up /etc/init.d/Firewall-6.sh restart
#
# For shutting down the interface
down /sbin/ip route del ::/0 dev he-ipv6 2>/dev/null
down /sbin/ifconfig he-ipv6 down 2>/dev/null
down /sbin/ip link set he-ipv6 down 2>/dev/null
post-down /sbin/ifconfig sit0 0.0.0.0 2>/dev/null
post-down /sbin/ifconfig sit0 down 2>/dev/null
post-down /sbin/ifconfig sit1 0.0.0.0 2>/dev/null
post-down /sbin/ifconfig sit1 down 2>/dev/null
post-down /sbin/modprobe -r sit 2>/dev/null
07:42:/home/nomad>ifconfig he-ipv6
he-ipv6: flags=209<UP,POINTOPOINT,RUNNING,NOARP> mtu 1480
inet6 fe80::d1b5:4da8 prefixlen 64 scopeid 0x20<link>
inet6 2001:470:39:57c::2 prefixlen 64 scopeid 0x0<global>
sit txqueuelen 1000 (IPv6-in-IPv4)
RX packets 2504594 bytes 2856452096 (2.8 GB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 1470748 bytes 248227701 (248.2 MB)
TX errors 542 dropped 0 overruns 0 carrier 536 collisions 0
07:44:/home/nomad>ip -6 route
::1 dev lo proto kernel metric 256 pref medium
2001:470:39:57c::1 dev he-ipv6 metric 1024 pref medium
2001:470:39:57c::/64 dev he-ipv6 proto kernel metric 256 pref medium
2001:470:4b:57c::/64 dev em1 proto kernel metric 256 pref medium
fe80::/64 dev he-ipv6 proto kernel metric 256 pref medium
fe80::/64 dev enp9s4 proto kernel metric 256 pref medium
fe80::/64 dev em1 proto kernel metric 256 pref medium
fe80::/64 dev em1.5 proto kernel metric 256 pref medium
fe80::/64 dev em1.10 proto kernel metric 256 pref medium
fe80::/64 dev em1.99 proto kernel metric 256 pref medium
fe80::/64 dev em1.101 proto kernel metric 256 pref medium
default via 2001:470:39:57c::1 dev he-ipv6 metric 1024 onlink pref medium
07:42:/home/nomad>ping -c 3 184.105.250.46
PING 184.105.250.46 (184.105.250.46) 56(84) bytes of data.
64 bytes from 184.105.250.46: icmp_seq=1 ttl=59 time=8.85 ms
64 bytes from 184.105.250.46: icmp_seq=2 ttl=59 time=8.55 ms
64 bytes from 184.105.250.46: icmp_seq=3 ttl=59 time=8.60 ms
--- 184.105.250.46 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2004ms
rtt min/avg/max/mdev = 8.553/8.668/8.854/0.132 ms
07:42:/home/nomad>ping -c 3 2001:470:39:57c::2
PING 2001:470:39:57c::2(2001:470:39:57c::2) 56 data bytes
64 bytes from 2001:470:39:57c::2: icmp_seq=1 ttl=64 time=0.070 ms
64 bytes from 2001:470:39:57c::2: icmp_seq=2 ttl=64 time=0.051 ms
64 bytes from 2001:470:39:57c::2: icmp_seq=3 ttl=64 time=0.059 ms
--- 2001:470:39:57c::2 ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2035ms
rtt min/avg/max/mdev = 0.051/0.060/0.070/0.007 ms
07:42:/home/nomad>ping -c 3 2001:470:39:57c::1
PING 2001:470:39:57c::1(2001:470:39:57c::1) 56 data bytes
--- 2001:470:39:57c::1 ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2041ms