Ubuntu 12.10 Server inital apt-get update taking a very long time

[sanderj]

All of those got stuck after "HTTP request sent, awaiting response..."

... and www.google.com went OK. Weird.

I'll now leave to you to narrow it down what is going between www.google.com versus the archive.ubuntu.com sites. Try different URLs, and see what happens. Remove one (or two?) of the routers. Connector your computer to another LAN and see if it works. In other words: explore & narrow it down.

With that info, I can help you further

[amosjackson]

Something weird: mirrors that timeout on the server load perfectly fine on other computers on the same network (and router)

[sanderj]

Something weird: mirrors that timeout on the server load perfectly fine on other computers on the same network (and router)

And what if you live-boot Ubuntu from a CD/USB-stick in the server hardware?

[amosjackson]

I forgot to tell you that I also have a raspberry pi webserver on the same router as this one. The router forwards port 80 to it. Also, live-booting made no difference

[amosjackson]

Oh, and one more thing: I can ping 'uk.archive.ubuntu.com' perfectly well but curl and wget time out.

[amosjackson]

Everything finally works!!! All I had to do was reduce the mtu from 1500 to 1412. Thanks for all your help, anyway.

[sanderj]

Everything finally works!!! All I had to do was reduce the mtu from 1500 to 1412. Thanks for all your help, anyway.

MTU? Ouch! That was the one thing I wanted to mention but I didn't because I thought it was too unlikely and too difficult.

How can MTU be a problem? Do you use some kind of tunneling / VPN / ... ?

[amosjackson]

I really don't know. I just read on a forum somewhere that lowering your mtu might solve a problem. And no, I don't use any tunnelling.

[sanderj]

You can manually discover the MTU size with "ping -s":

ping -c4 -M do -s 900 nl.archive.ubuntu.com
ping -c4 -M do -s 1400 nl.archive.ubuntu.com
ping -c4 -M do -s 1500 nl.archive.ubuntu.com

Note: add 28 to that number to get the MTU size.

EDIT: one-liner to get the MTU:

$ ping -c1 -M do -s 10000 www.google.com | grep mtu | awk '{ print $NF }' | sed -e s/\)//
1500

HTH