nanog mailing list archives

Re: Connectivity to Brazil


From: Rubens Kuhl <rubensk () gmail com>
Date: Wed, 2 Feb 2011 12:15:05 -0200

CTBC has capacity from GBLX, TIWS and SEABONE, although not all
prefixes are announced to all providers. TIWS usual path in the US is
thru Level 3, so steering the traffic to Level 3 might do the trick.


Rubens


On Wed, Feb 2, 2011 at 11:08 AM, Steve Danelli <the76posse () gmail com> wrote:
Thanks Vinny - how did you route around?   There seems to be one path from the US to Brazil via GBLX and CTBC.    Are 
you leveraging leased connectivity?   Thanks for the info!!

SD

Sent from my iPhone

On Feb 2, 2011, at 1:21 AM, Vinny Abello <vinny () abellohome net> wrote:

We saw similar issues with IKE through Global Crossing (as odd as that sounds) out of the NYC market at the same 
time. We routed around them and problem solved. Still scratching our heads on that one... In my experiences, GLBX 
has numerous odd issues to the point where it's become a bad joke anytime something breaks with connectivity... we 
blame them. It's kind of not funny though because it's almost always true. Taking them out of the equation usually 
fixes the problem. One of our customers who is frequently affected by GBLX problems jumps to the (often correct) 
conclusion that they are causing problems. :-/

-Vinny

On Feb 1, 2011, at 3:57 PM, Steve Danelli wrote:

Thanks for the response.

Ike had worked great up until Monday.  The provider did a local test and our box saw the Ike packets so it appears 
to lie somewhere upstream.  (GLBX may be a good guess)

Also - the paths are stable and we are sourcing from the same ip - very strange behaivor.    Hope someone from GLBX 
or CTBC (or someone who had experienced an issue like this) can assist


Thanks to all for their feedback so far.

SD

On Feb 1, 2011, at 3:19 PM, Valdis.Kletnieks () vt edu wrote:

On Tue, 01 Feb 2011 08:54:47 EST, Steve Danelli said:

Some carrier, somewhere between us and the service provider is selectively
dropping the IKE packets originating from our VPN gateway and destined for
our Brazil gateway. Other traffic is able to pass, as are the IKE packets coming
back from Brazil to us. This is effectively preventing us from establishing
the IPSEC tunnel between our gateways.

Has IKE been known to work to that location before? Or is this something new?
My first guess is some chucklehead banana-eater at the service provider either
fat-fingered the firewall config, or semi-intentionally blocked it because it
was "traffic on a protocol/port number they didn't understand so it must be
evil".

Also something else is awry, for two given hosts on the same subnet (x.y.z.52
and x.y.z.53), they take two wildly divergent paths:

Anyone have any insight on to what may be occurring?

The paths appear to diverge at 67.16.142.238.  I wonder if that's gear trying
to do some load-balancing across 2 paths, and it's using the source IP as a
major part of the selector function ("route to round-robin interface source-IP
mod N" or similar?).

The other possibility is your two traceroutes happened to catch a routing flap in
progress (obviously not the case if the two routes are remaining stable).

Sorry I can't be more helpful than that...






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