# IPV6 gateway requires IPFW restart before working



## johnpeeb (May 8, 2011)

I'm trying to set up an 8.2-RELEASE gateway for an IPV4/6 LAN. After booting the gateway, LAN clients are unable to ping external IPV6 adresses. However, if I stop ipfw on the gateway, I am able to ping external hosts from the LAN. The weird thing is that if after booting the gateway, I stop ipfw, then ping an external ipv6 host from a LAN computer, then start ipfw again, I am still able to access external IPV6 hosts (including ones other than the one I previously pinged) from the LAN, resolving the issue.

Note that the ping step is required. If I don't do that, then when IPFW is reenabled, I still won't be able to connect to IPV6 hosts. However, if I first disable IPFW, ping, then reenable it, things will still work if I subsequently restart IPFW without doing a ping in the middle.

Here is a bit more information that may or may not be relevant.

The clients are Windows 7 laptops. Even before restarting IPFW, they are able to successfully autoconfigure a global IPV6 address.

IPV4 connectivity through the gateway works fine. The gateway itself has no issues with IPV6 connectivity.

The firewall rules do not discriminate between IPV4 and IPV6 traffic except in two cases: a rule allowing 6to4 traffic in only applies to ip4 traffic and the rule allowing icmp6 traffic only applies to ip6 traffic.

The IPV6 routing table (as reported by netstat) is unchanged after performing the procedure. The IPFW rules before and after performing the procedure are the same.

The first ping reply received when doing the procedure takes 2-4 times as long as the other ones.


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