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Internal routing problem

Community Veteran
Posts: 1,136
Thanks: 2
Registered: ‎30-07-2007

Internal routing problem

Howdy,
There appears to be a problem with routing across gateways.
I'm trying to access my home server, which I know is up and working as I can access it from work, but it is timing out from my partner's PN connection.
This is what a traceroute shows
Tracing route to *.avatastic.co.uk [84.92.17.xxx]
over a maximum of 30 hops:
  1    <1 ms    <1 ms    <1 ms  192.168.1.1
  2    20 ms    36 ms    20 ms  lo0-central10.ptw-ag02.plus.net [195.166.128.196]
  3    21 ms    20 ms    20 ms  link-a-central10.ptw-gw01.plus.net [212.159.2.148]
  4    19 ms    20 ms    19 ms  xe-0-2-0.ptw-cr01.plus.net [212.159.0.248]
  5    20 ms    39 ms    20 ms  ae2.ptw-cr02.plus.net [195.166.129.5]
  6    58 ms  102 ms    85 ms  ae1.pcl-cr02.plus.net [195.166.129.3]
  7    19 ms    31 ms    29 ms  te4-5.pcl-gw02.plus.net [212.159.0.219]
  8    21 ms    22 ms    21 ms  link-b-central10.pcl-ag07.plus.net [212.159.2.187]
  9    *        *        *    Request timed out.

This is what the trace back looks like:

adw@skynet:~$ traceroute 146.90.65.xxx
traceroute to 146.90.65.xxx (146.90.65.xxx), 64 hops max, 52 byte packets
1  lo0-central10.pcl-ag07.plus.net (195.166.128.188)  33.405 ms  28.543 ms  27.768 ms
2  link-a-central10.pcl-gw01.plus.net (212.159.2.184)  23.541 ms  26.530 ms  25.047 ms
3  xe-9-0-0.pcl-cr01.plus.net (212.159.0.216)  24.570 ms  114.915 ms  34.954 ms
4  ae2.pcl-cr02.plus.net (195.166.129.7)  27.385 ms
    ae1.ptw-cr01.plus.net (195.166.129.0)  25.176 ms  26.348 ms
5  ae1.ptw-cr02.plus.net (195.166.129.2)  24.598 ms
    te8-5.ptw-gw01.plus.net (212.159.0.249)  25.402 ms  26.013 ms
6  te8-5.ptw-gw02.plus.net (212.159.0.251)  24.939 ms  27.036 ms  24.023 ms
7  link-b-central10.ptw-ag02.plus.net (212.159.2.151)  25.840 ms  27.618 ms
8  * * *

As you can see from the trace from my IP there are multiple responces on hops 4 and 5.
A gateway hop will probably fix this (which I'm about to attempt) but I thought I'd bring it to dave's attention.
Cheers,
A.
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)
2 REPLIES
Plusnet Staff
Plusnet Staff
Posts: 12,169
Thanks: 18
Fixes: 1
Registered: ‎04-04-2007

Re: Internal routing problem

There's multiple routes across the core but they're evenly weighted so it could take any path.
PCL-CR01 is connected to PCL-CR02 and PTW-CR01 but not PTW-CR02 so to get from PCL-CR01 to PTW-CR02 it has to go via PCL-CR02 or PTW-CR01 but there's an equal chance of each route on the way out and on the way back.
Be interested to see if it gets fixed with a disconnect.
Community Veteran
Posts: 1,136
Thanks: 2
Registered: ‎30-07-2007

Re: Internal routing problem

Hi dave,
It was fixed with a disconnect by the 146.90.65.xxx address.
If it happens again (it also happened on Friday and Saturday) I'll do a gateway hop from the 84.92.17.xxx end instead to see if that fixes it.
F9 member since 4 Sep 1999
F9 ADSL customer since 27 Aug 2004
DLM manages your line the same way DRM manages your rights.
Look at all the pretty graphs! (now with uptime logging!)