[ale] Cablemodem shows in my traceroutes?

[Drag0n]

	It is common for frame providers to route traffic across their internal
network using assigned private numbers. A cablemodem is in a way, a
hybid ATM frame relay network. What looks like is happening is some
admin of the network is either cut and pasted the wrong host name into
the dns table or they are just using a simple name to refer to the core
cablemodem router. If everything works as its supposed to, (you can get
out and data can get in) then there is nothing to worry about. I get a
similar situation from home, but am able to access my home systems
remotely so no routing problems there.

 1  * * *  (I drop all icmp trafic aimed at my firewall, internal or
external)
 2  10.238.252.1 (10.238.252.1)  7.257 ms  9.202 ms  11.586 ms
 3  c-66-56-66-2.atl.client2.attbi.com (66.56.66.2)  7.950 ms  11.592
ms  8.365 ms
 4  c-66-56-23-38.atl.client2.attbi.com (66.56.23.38)  8.265 ms  10.729
ms  8.158 ms
 5  c-66-56-22-146.atl.client2.attbi.com (66.56.22.146)  8.186 ms 
23.566 ms  9.122 ms

Drag0n
dragon at atlantacon.org

"Robert L. Harris" wrote:
> 
> I'm trying to debug some IPv6 and just ran a traceroute from behind my
> firewall:
> 
> {0}:/usr/src/kernel>traceroute www.kame.net
> traceroute to apple.kame.net (203.178.141.220), 30 hops max, 38 byte
> packets
>  1  wally (192.168.0.1)  0.249 ms  0.154 ms  0.130 ms
>  2  cablemodem (10.2.0.1)  31.877 ms  9.824 ms  66.160 ms
>  3  209.186.118.17 (209.186.118.17)  11.221 ms  11.911 ms  9.951 ms
>  4  172.26.96.2 (172.26.96.2)  13.143 ms  9.803 ms  15.492 ms
>  5  65.90.64.5 (65.90.64.5)  13.588 ms  12.239 ms  12.465 ms
>  6  P5-0.c0.atln.broadwing.net (216.140.12.41)  12.650 ms  12.825 ms 12.056 ms
>  7  p3-0.c0.wash.broadwing.net (216.140.8.109)  22.946 ms  24.353 ms 23.576 ms
> .
> .
> .
> 
> umm, this is odd as the external interface of my firewall (wally) has a
> valid IP (24.216.225.11)...
> 
> From my firewall:
> 
> raceroute to apple.kame.net (203.178.141.220), 30 hops max, 38 byte
> packets
>  1  cablemodem (10.2.0.1)  77.861 ms  20.864 ms  8.453 ms
>  2  209.186.118.17 (209.186.118.17)  24.057 ms  39.684 ms  9.449 ms
>  3  172.26.96.2 (172.26.96.2)  12.061 ms  10.679 ms  10.443 ms
>  4  65.90.64.5 (65.90.64.5)  19.208 ms  11.687 ms  12.402 ms
>  5  P5-0.c0.atln.broadwing.net (216.140.12.41)  19.451 ms  12.975 ms 16.829 ms
>  6  p3-0.c0.wash.broadwing.net (216.140.8.109)  27.234 ms  29.734 ms 23.076 ms
> 
> Anyone else see this?  Is it normal?  I thought the cable modems acted
> like a transparent bridge and wouldn't show in traceroutes, etc...
> 
> Robert
> 
> :wq!
> ---------------------------------------------------------------------------
> Robert L. Harris                     | PGP Key ID: E344DA3B
>                                          @ x-hkp://pgp.mit.edu
> DISCLAIMER:
>       These are MY OPINIONS ALONE.  I speak for no-one else.
> 
> Diagnosis: witzelsucht
> 
> IPv6 = robert at ipv6.rdlg.net     http://ipv6.rdlg.net
> IPv4 = robert at mail.rdlg.net     http://www.rdlg.net
> 
>   ------------------------------------------------------------------------
>    Part 1.2Type: application/pgp-signature

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