[afnog] problem with network

[Scott Weeks]

On Tue, Dec 8, 2009 at 1:17 PM, Scott Weeks <surfer at mauigateway.com> wrote:
> --- brhunild at gmail.com wrote:-------
> I am having a problem with one of my network.
> Since two days I can ping my IP address from different looking glasses but
> I can't traceroute. I am suspecting my transit provider to do Filtrering at the host
> ----------------------------------------
> If you have access to a unix box use tcptraceroute.  If you can get through
> with that on certain ports, like port 80, and not with traceroute you can be
> pretty sure it's a filter.  I know there is a tcptraceroute-like program for
> windows, but I can't remember what it is at this time.

--- brhunild at gmail.com wrote:

Thanks Scott, I think there might be also a routing issue.

I asked  friends to traceroute my bloc from different part of the world.

My  IP block seems to be announced by Seabone and Pccw.

>From my friends who see the SEABONE path they can ping me.

Those who see the PCCW path can't and their traffic is blocked at one host
in PCCW's network.

How can I convince my transit provider on what to do? He is totally quiet.
-------------------------------------

Two questions:

1) What do you mean by "their traffic is blocked at one host in PCCW's network"?  Is just traceroute blocked or is regular traffic blocked?  I believe you mean ICMP (traceroute/ping) is blocked.  Or you'd have a much bigger problem as some customers could not get to your network at all and there would probably be a routing issue.  This could be caused by PCCW announcing reachability to your prefixes into the global BGP tables when they actually don't get the traffic to you.  tcptraceroute would show you this as it uses the first packets of the TCP 'three-way handshake' instead of using ICMP.  You'd have your friends who can't get to your network (at all) use the tool and see where it stops.  They would not be able to get to your network al all if this was the case because they'd see a better path through PCCW and never attempt to use SEABONE.

2) I see that the traceroutes posted to the list get to you eventually and there're some timeouts (* * * in the trace) in the middle where PCCW's routers should show up.  Do you know if PCCW does MPLS?  This could be the cause, or they could be blocking ICMP *to* their routers and not blocking ICMP *through* their routers.


scott



ps. The tcptraceroute-like tool for windows is called "tracetcp" and is found here: tracetcp.sourceforge.net.  
















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