[CLUE-Tech] Access to ATT Cable systems? (more)

[David Anselmi]

Dave Price wrote:
[...]
> 
> There is a linksys router doing NAT involved, but I have already set up
> port forwarding - When PCAW failed to connect, I fell back to ping /
> traceroute to the router interface ... and this fails too.

If you can't get from 12.254.89.67 (or the PC behind that IP, if that's 
where you're coming from) to the nearest router (the Linksys), that 
localizes the problem pretty well.  But that probably isn't what you 
meant, is it?

> 
> I also tried accessing the PCAW 'remote' site (another attbi.com system)
> this is at 12.254.88.143, and connected directly to the cable modem (no
> router or NAT on the client side.  IP address again confirmed by
> winipcfg and syslog entries on my own host.  

[...]
> 
> I suspect that att is doing some NAT or filtereing of their own at the
> head-end ....

They may be, but these IPs are not unroutable--they just don't answer. 
My traceroutes to both end at 12.244.73.137.  Can you trace from one of 
the problem att systems to somewhere?  How many hops between 
12.254.88.143 and 12.244.73.137?  I would expect it to be only one, 
which indicates that it's the cable modem (or the box plugged into it) 
that's the problem.  But if it's more than one hop, that supports 
filtering by att.

You can trace between all the various systems to try to get a feel for 
what the network topology is, so you'll have an idea where the packets 
disappear.  That might give you some ammo if you call tech support.

Maybe an att user has some better ideas?  Anyone successfully running a 
server on a cable modem (especially on the 12.254 subnet)?

Sorry I'm not more help.

Dave