Metronet - Priority Problems

Problem: [57865] Routing problems affecting access to Sheffield-based services

Status: Closed

Problem description Added on: 18/08/2009 @ 08:48

There are a considerable amount of customers reporting problems access some Plusnet-hosted services including (but not limited to) our email servers, websites, webmail, community site and homepages. The majority of the problems being seen are from customers connecting via gateways hosted at our City Lifeline data centre.

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Comment updated on: 18/08/2009 @ 09:09

Our Networks Team are currently investigating this problem as a matter of urgency.

Comment updated on: 19/08/2009 @ 11:33

Analysis of the examples provided by affected customers suggests that the problem occurs where traffic is passing through our city lifeline gateways. This can be ascertained by running a traceroute as follows:

Tracing route to webmail.plus.net [84.92.1.1]
over a maximum of 30 hops:

1 2 ms 2 ms 1 ms home.gateway [192.168.1.254]
2 24 ms 22 ms 25 ms lo0-plusnet.**pcl-ag01**.plus.net [195.166.128.27]
3 27 ms 23 ms 23 ms gi1-2-803.**pcl-gw1**.plus.net [84.92.5.57]
4 * * * Request timed out.

If this assumption is correct then customers affected should be able to temporarily resolve the problem by rebooting their router or modem until they connect to a gateway that doesn't send traffic via the 'pcl' routers.

Comment updated on: 19/08/2009 @ 11:33

The CPU load on pcl-scs01 seems to be a lot higher than for the other switches.

Comment updated on: 19/08/2009 @ 11:34

We have now reloaded pcl-scs01. The CPU load is returning to normal levels and we will continue monitoring for further reports of problems.

Comment updated on: 19/08/2009 @ 11:35

Further reports continue to be received from customers unable to connect to Plusnet hosted services, in particular email. However there have also been reports of problems accessing our website and FTP servers.

Comment updated on: 19/08/2009 @ 11:35

There were some OSPF routing changes made around the time that problems started being reported. We're currently investigating the possibility that these changes may be causing/contributing to the problem.

Comment updated on: 19/08/2009 @ 11:45

It doesn't look like the routing changes are to blame so we're now looking at the traffic flows of some of the affected customers.

Comment updated on: 19/08/2009 @ 14:59

No problems seen with customers' traffic flows however we have noticed what we think to be a routing anomoly on the network that we're taking a look at now.

Comment updated on: 19/08/2009 @ 15:23

We've corrected some routing anomolies.

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