[ale] Stupid IP question

[JK]

Greg Freemyer wrote:
> On Jan 14, 2008 2:45 PM, List <lst at wiencko.net> wrote:
>> Yeah, actually traceroute does.  Just tried it on several machines.  It
>> nicely give me the network facing interface as the first hop after my
>> router.
>>
> 
> That is a special situation of some sort.
> 
> In general, each router has a source-facing IP and destination facing IP.
> 
> traceroute should give you the source-facing IP.

I think it's implementation-dependent.  An IP stack might
decrement the TTL on the inbound side or the outbound
side, and the resulting ICMP message might originate from
either interface.  RFC 791 doesn't mandate the exact
behavior.

-- JK

-- 
"What can be asserted without evidence can also be
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