From: Shahid Shafi (sshafi@gmail.com)
Date: Sun Feb 13 2005 - 18:49:15 GMT-3
Thanks Alex,
What about same ip in multiple hops 10.222.148.8? This means atleast
three probe packets hit the same interface. What does that indicate?
On Sun, 13 Feb 2005 14:10:25 +0100, Alexander Arsenyev (GU/ETL)
<alexander.arsenyev@ericsson.com> wrote:
> Let me guess :-)
> The errors are on return path (ICMP TTL Exceeded has wrong ICMP checksum)
> and appear only after 6th hop (on 7th and 8th hops). Are you able to capture
> ICMP TTL exceeded packets and verify that ICMP checksum is definitely wrong?
> Or could it be just 0x0000 which is technically wrong but for a different reason
> (botched IP stack implementation)?
> Another guess is that you may have incorrectly working NAT after 6th hop which changes
> IP addresses embedded into ICMP message but forgets to update ICMP checksum.
> HTH,
> Cheers
> Alex
>
> -----Original Message-----
> From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]
> Sent: 13 February 2005 12:08
> To: ccielab@groupstudy.com
> Subject: Traceroute checksum errors
>
> Hi Gurus,
>
> traceroute to (10.222.148.8), 30 hops max, 38 byte packets
> 1 x.x.x.x 0.229 ms 0.203 ms 0.192 ms
> 2 y.y.y.y 0.223 ms 0.214 ms 0.207 ms
> 3 10.0.1.10 0.263 ms 0.251 ms 0.244 ms
> 4 10.0.4.97 0.505 ms 0.467 ms 0.861 ms
> 5 192.168.52.250 39.225 ms 39.079 ms 38.858 ms
> 6 10.222.148.8 40.300 ms 40.550 ms 40.570 ms
> 7 10.222.148.8 39.821 ms 40.539 ms 42.491 ms
> Icmp checksum is wrong
> 8 10.222.148.8 40.068 msIcmp checksum is wrong
> 40.314 msIcmp checksum is wrong
> 40.588 ms
>
> What can you say about this output? Checksum errors?
>
> Thx
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Thu Mar 03 2005 - 08:51:20 GMT-3