[143010] in North American Network Operators' Group
re: Comcast Bussiness Class and GRE Tunnels
daemon@ATHENA.MIT.EDU (Nick Olsen)
Tue Jul 26 11:34:57 2011
From: "Nick Olsen" <nick@flhsi.com>
To: "Nate Burke" <nate@blastcomm.com>, "NANOG list" <nanog@nanog.org>
Date: Tue, 26 Jul 2011 11:34:25 -0400
Reply-To: nick@flhsi.com
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
I had to deal with this Exact problem last week. Never got EOIP to work,
Spent hours on it.
I had to use a "GRE Tunnel" Which is the same thing. And is only available
under RouterOS 5.x+. Came right up when EOIP wouldn't. I don't know how to
peg the problem. As PPTP, EOIP, GRE...etc All use the GRE protocol 47. So
you would think they all would show the same problem.
I never even attempted to contact comcast support as I wasn't about to
spend another 3 hours explaining my problem only for them to say they
aren't blocking anything and it must be my side..
Nick Olsen
Network Operations
(855) FLSPEED x106
----------------------------------------
From: "Nate Burke" <nate@blastcomm.com>
Sent: Tuesday, July 26, 2011 11:07 AM
To: "NANOG list" <nanog@nanog.org>
Subject: Comcast Bussiness Class and GRE Tunnels
Hello, I'm hoping that someone here might have run into a similar issue
and might be able to offer me some pointers.
I have a customer that I am providing redundant paths to, one link over
a microwave connection, and a backup link over a Comcast Business Class
Connection. Everything on the Microwave link is working fine. On the
Comcast Connection, I have a Static IP from Comcast, and I want to setup
a vendor specific GRE tunnel (Mikrotik EoIP) from my NOC to the Comcast
Static IP Address. It looks like the SPI Firewall inside the SMC
Gateway required by comcast is blocking the GRE packets, I'm basing this
on the fact that when I power cycle the modem, I get 1 ICMP Packet
through the GRE Tunnel while the modem is booting up, then it stops
again. I have gotten to Tier2 support who swears that all Firewalls on
the SMC Gateway are disabled.
As a workaround, I was able to establish a PPTP tunnel to my NOC,
however it seems like the tunnel will only run for a few hours, then
becomes slow to the point of being unusable. In my mind this would be
no different than setting up a permanent VPN back to a corporate office,
which I would think happens all the time, so I'm not sure why I'm
running into issues with it.
Anyone with Insights or comments would be appreciated.
Thanks,
Nate Burke
