Cool IPv6 Stuff

Donald Stahl don at
Tue Jun 5 03:36:52 UTC 2007

> Won't stateful firewalls have similar issues? Ie, if you craft a stateful
> firewall to allow an office to have real IPv6 addresses but not to allow
> arbitrary connections in/out (ie, the "stateful" bit), won't said stateful
> require protocol tracking modules with similar (but not -as-) complexity
> to the existing NAT modules?
It's a lot easier to write a firewall module that monitors a SIP 
connection to allow for bi-directional traffic than it is to monitor for 
such connections and rewrite the packets.

Not to mention- what happens when the SIP traffic (for example) goes out 
with 1918 addresses in the packets? The firewall never sees the return 
traffic because the destination system is trying to send traffic to a 
private address- it gets lost in the ether and troubleshooting becomes a 
pain. With real addresses in the packets the traffic will at least make it 
back to the firewall- even if the firewall doesn't know how to handle 
them. At that point you know what's happening and can either correct the 
rules, enable a proxy, or yell at your firewall vendor.


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