Routing loop?

jstadter · ‎10-22-2002

We are having sporadic e-mail and web problems. When I did a tracert from an external IP to my mail server, this is the result of the trace:

1 * * * Request timed out.

2 170 ms 190 ms 170 ms L1E1.FRGO.splitrock.net [209.254.124.129]

3 200 ms 200 ms 200 ms DNV2-SNF3.splitrock.net [63.253.30.202]

4 200 ms 200 ms 221 ms pos1-1.core1.SanFrancisco1.Level3.net [166.90.50

.169]

5 200 ms 190 ms 200 ms ggr1.sffca.ip.att.net [166.90.50.162]

6 220 ms 201 ms 200 ms tbr1-p013302.sffca.ip.att.net [12.122.11.217]

7 250 ms 251 ms 250 ms tbr1-cl1.cgcil.ip.att.net [12.122.10.5]

8 241 ms 240 ms 260 ms gbr6-p40.cgcil.ip.att.net [12.122.11.46]

9 251 ms 250 ms 250 ms gar1-p360.mpsmn.ip.att.net [12.122.2.221]

10 250 ms 260 ms 261 ms 12.126.248.54

11 270 ms 260 ms 261 ms moor-ps-T2.702communications.net [216.239.3.250]

12 261 ms 270 ms 260 ms mail.moorhead.k12.mn.us [216.239.1.11]

13 260 ms 261 ms 260 ms mail.moorhead.k12.mn.us [216.239.1.11]

Trace complete.

Why do I get a return twice from the mail server? This also happens on all of our other resources as well.

We just bought and installed a Cisco 2691 that has two T1's ppp multilinked to our ISP.

Is this something to do with the Multilinking? Any ideas would be great.

Thanks!

uniemeyer · ‎10-24-2002

HI,

everythin is fine with that traceroute. It seems that the mail-server first

responsed to the "TTL exceeded" (This behavier is not normal but is nothing

to worry about) and the second response is due to the "port unreachable message" you get back from that server, because your traceroute ( if you

using a unix based machine) uses UDP packets with a UDP port that

is not used.

Windows uses ICMP Ping packet for the tracert functionality.

Sorry, but your problem must be another.

regards Ulrich Marzoli