The prepeding should have nothing to do with your lack of connectivity through Cogent. All the prepending would do is possibly make another route look more desireable due to the as-path. They already append their ASN when you pass through their AS.
As a second note... are you allowing UDP ports for traceroute? I can trace 208.74.141.252 with ICMP, but with UDP I drop right at your edge. Cisco uses UDP by default. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Tim Durack Sent: Friday, November 16, 2007 8:47 AM To: Cisco-nsp Subject: [c-nsp] Level3/Cogent/HVDataNet specific routing problem - looking for suggestions Having difficulties with routing through a Level3 circuit: Traceroute using 67.99.58.158 source address: RTR-3#traceroute 38.102.194.142 Type escape sequence to abort. Tracing the route to HudsonValleyDataNet.demarc.cogentco.com (38.102.194.142) 1 67.99.58.157 [AS 6395] 8 msec 4 msec 4 msec 2 so-7-0-0.edge5.NewYork1.Level3.net (4.68.63.17) [AS 6395] 12 msec 4 msec 4 msec 3 ae-32-89.car2.NewYork1.Level3.net (4.68.16.132) [AS 6395] 4 msec 4 msec 4 msec 4 COGENT-COMM.car2.NewYork1.Level3.net (4.68.111.46) [AS 6395] 8 msec 4 msec 4 msec 5 v3503.na21.b001105-25.jfk05.atlas.cogentco.com (38.20.32.162) [AS 6395] 12 msec 12 msec 8 msec 6 HudsonValleyDataNet.demarc.cogentco.com (38.102.194.142) [AS 6395] 152 msec * 8 msec Traceroute using 208.74.141.252 source address: RTR-3#traceroute Protocol [ip]: Target IP address: 38.102.194.142 Source address: 208.74.141.252 Numeric display [n]: Timeout in seconds [3]: Probe count [3]: Minimum Time to Live [1]: Maximum Time to Live [30]: Port Number [33434]: Loose, Strict, Record, Timestamp, Verbose[none]: Type escape sequence to abort. Tracing the route to HudsonValleyDataNet.demarc.cogentco.com (38.102.194.142) 1 67.99.58.157 [AS 6395] 4 msec 4 msec 4 msec 2 so-7-0-0.edge5.NewYork1.Level3.net (4.68.63.17) [AS 6395] 4 msec 4 msec 4 msec 3 ae-32-89.car2.NewYork1.Level3.net (4.68.16.132) [AS 6395] 4 msec ae-22-79.car2.NewYork1.Level3.net (4.68.16.68) [AS 6395] 4 msec 4 msec 4 COGENT-COMM.car2.NewYork1.Level3.net (4.68.111.46) [AS 6395] 20 msec 4 msec 5 * * * 6 * * * 7 I'm assuming 208.74.141.0/24 is getting dropped at hop 5 due to filtering. Not having issues anywhere else. I have a ticket open with Level3, but would like to see if I can work around this with some community triggered prepending. Looking at Level3's community support, I think I could get 208.74.141.0/24 prepended for Cogent peering: -------------------------------------------------------- customer traffic engineering communities - Prepending -------------------------------------------------------- 65001:0 - prepend once to all peers 65001:XXX - prepend once at peerings to AS XXX 65002:0 - prepend twice to all peers 65002:XXX - prepend twice at peerings to AS XXX 65003:0 - prepend 3x to all peers 65003:XXX - prepend 3x at peerings to AS XXX 65004:0 - prepend 4x to all peers 65004:XXX - prepend 4x at peerings to AS XXX So something like: route-map level3-out set community 65001:174 ! Does that have a chance of working? Do I have to soft-reset the session to get the community propagated? Thanks, Tim:> _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
