[...]
> given some other measures PIX takes to 
> try to keep
> a low profile, like not decrementing TTL's in the IP header.  But then
> again, that example is really another case of making yourself
> identifiable by trying to make yourself unidentifiable... 
> d'oh... double
> irony.
> 
> Michael

That's interesting - that should make it virtually impossible to map a PIX
ruleset with hping2 or firewalk (which is good) but it breaks the RFC for IP
routers (which is possibly bad).

(From RFC 791)
"[The IP TTL field] must be decreased at each point that the internet header
    is processed to reflect the time spent processing the datagram."

I'm happy with how bridge-mode firewalls work, but the PIX acts as a router,
with all interfaces having an IP address - there's something wrong here...

Cheers,

--
Ben Nagy
Network Security Specialist
Marconi Services Australia Pty Ltd
Mb: +61 414 411 520  PGP Key ID: 0x1A86E304 
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