Re: [gentoo-user] [OT] Pinging two devices on the same IP address

[Mick]

On Wednesday 24 October 2007, Etaoin Shrdlu wrote:
> On Wednesday 24 October 2007, Mick wrote:
> > Thanks guys.  The AP has a reserved static LAN IP address on the
> > router (10.10.10.13).  It also has a MAC.  So it is simply a matter of
> > forwarding (all) ICMP echo-reply packets that arrive from the Internet
> > to that LAN address. (On this implementation the AP is itself a
> > Linksys wireless router).
> >
> > I wonder if I can play tricks with ping's ICMP headers to
> > differentiate between them as they come into the router, or something
> > clever that I haven't yet figured out.  Any ideas?
>
> Disclaimer: I have not tested what follows.
>
> Can't you just use traceroute?
> If you run tracert from windows, it should already work, since it uses
> ICMP echo requests. Otherwise, you should open UDP port 33434 on the
> router.

I don't have access to a MS Windows machine right now, but using mtr I get:
====================================================
 [snip . . .]

 23. XX-XX-XXX-XX.dhcp.kgpt.tn.cha  6.7%    15  145.5 145.4 143.2 146.9   1.3
 24. ???                          100.0    15    0.0   0.0   0.0   0.0   0.0
 25. XX.XX.XXX.XXX                 6.7%    15  155.9 156.2 154.2 159.1   1.3
====================================================

It seems that hop 23 is the dhcp server of the ISP. Hop 25. is the public IP 
address of the router.  I assume that hop 24. is the cable modem which acts 
as a bridge(?).

Since the AP is within the LAN and the connection to it is NAT'ed, it is not 
shown above.  Am I correct in my thinking?
-- 
Regards,
Mick