Computer Laboratory

Local System Information

This page offers pointers to detail of how to use lab systems, how to get help, and so on.

Getting help and introductory documents

Administrative matters

Workstation provision

Systems software

Communications and the network

Facilities

If you spot things missing from this page and its sub-pages, please notify sys-admin@cl.cam.ac.uk.

[rss feed]Sys-admin news

24 Feb 2014

Further NTP related changes

With the new routers, Lab machines lost the ability to NTP probe machines on the internet, as we lost stateful UDP reflexive rules.
With the recent NTP amplification attacks, we have added rules which mean that machines on the internet cannot NTP probe most Lab machines (our NTP servers should still be accessible).
Peerings (where source and destination ports are both 123) should still work.

18 Jan 2014

Purge of unused VLAN 100 IP addresses

As part of a campaign to clear the use of the original lab subnet, IP address on VLAN 100 in the subnet 128.232.0.0/20 which are believed not to have not been used for a year have been removed from the DNS. Further pruning is likely in future. If you believe an address has been retired but is still needed, please email sys-admin

23 Dec 2013

WordPress upgraded to 3.8

The instance of wordpress used for http://www.cl.cam.ac.uk/news/ has been upgraded to 3.8.
Please report any problems to sys-admin.

15 Nov 2013

DNSSEC for cl.cam.ac.uk

On Monday 18th November 2013 we plan to add a DS RR for cl.cam.ac.uk to the cam.ac.uk zone. This will mean that resolvers using DNSSEC will check our information, and ignore it if the information does not have a valid signature. Apart from making our information more secure, it also has the ability to take cl.cam.ac.uk out of the DNS if something goes wrong. Please report any DNS problems with cl.cam.ac.uk

18 Sep 2013

Filer running slowly

The filer is running slowly at the moment. This is because we’re copying
the entire filesystem to the replacement machine. The ultimate goal is
to make everything faster, but in the short term we have to suffer some
pain.