20150423 – Level3 IP Transit Failure

At 1:34pm we received alerts regarding some destinations being unreachable.

Further investigation showed that our fibre link to Level3 was down unexpectedly.  This caused a BGP routing event.

Our configuration started the BGP reconvergance process as soon as the router saw the fibre link drop and outbound traffic was re-routed via other paths.

Other routers on the internet would take around 3-4 minutes to re-learn the alternate paths for inbound.  This is out of our control.

This only affected paths via Level3 and not via our other connectivity partners and as such would appear as a partial outage.


We have contacted Level3 and raised a ticket to investigate.  Our network is fully operational via alternate connectivity.

Advisory – HTTP.sys Remote Code Execution Vulnerability

A security vulnerability in various MS Windows OS’s

A remote code execution vulnerability exists in the HTTP protocol stack (HTTP.sys), and has the common vulnerability and exposures designation of CVE-2015-1635. It is caused when HTTP.sys improperly parses specially crafted HTTP requests. An attacker who successfully exploited this vulnerability could execute arbitrary code in the context of the System account. Effectively, this security bug allows attackers to knock windows web servers offline by sending a simple HTTP request, resulting in a blue screen of death.

Microsoft have fixed this with the recent patch Tuesday round of updates.

For more information see:

Or search for ‘ HTTP Pings of Death ‘ or ‘ CVE-2015-1635

If you have any further questions, please email support@netnorth.co.uk

Netnorth Support

Short fibre outage

We experienced a short fibre outage on one of our fibre circuits between Bolton and Manchester overnight.

This started at 12:05am and concluded at 12:52am.

No maintenance was scheduled for this period so we are awaiting a RFO (reason for outage) from VirginMedia for the circuit.


Due to our redundant ring topology network, traffic was automatically re-routed via our other vendor circuits within seconds and no outages were experienced.