Network debugging guide
Contents
- 1 Network debugging guide for Free Geek Vancouver
Network debugging guide for Free Geek Vancouver
Common/semi-common issues
Network not working
Symptoms
Nothing works from one computer, other computers work fine. Or all the computers in an area are down. When attempting to debug always make sure the problem occurs on at least one other computer which is in a different room (actually a different switch).
Resolution
- Ensure network cable is plugged into machine
- Ensure the cable is plugged into a switch which is turned on
- Ensure the switch is connected to the rest of the network
- Reboot the switch
Internet connection down
Symptoms
Unable to visit an external website such as http://www.google.com/ or http://www.cbc.ca/. Internal websites such as http://fgdb.shop.lan/ and http://tasks.shop.lan/ are still available.
Resolution
- Ensure the cable modem has power and appropriate lights on (FILLIN).
- Reboot the router (nut)
Rebooting the router will disrupt all internal traffic and may take a couple of cycles before the internet works, be sure to give enough time after rebooting before testing again (5 minutes generally).
Generally slow/very slow network
Symptoms
Both internal (http://fgdb.shop.lan/) and external websites such as http://www.google.com/ or http://www.cbc.ca/ load slowly or intermittently. In the console running a command such as ping fir.shop.lan returns a time larger than 1-2 ms (such as 6ms).
Resolution
This has generally been caused by a switch having some difficulties, rebooting the switch generally fixes it. The two most likely switches are the D-Link switch in the back of the rack (pull the Keyboard/monitor out the front of the rack and then you can get access to the power cable from the rear of the rack) and the matching D-Link switch on top of the cupboards in the mezzanine. ping fir.shop.lan should usually have a time of less than 1ms (such as time=0.735ms) after rebooting the switch.
DHCP Down
Symptoms
After rebooting any terminal it will not allow any user login. Freshly booted build machines will not show an active network connection. Running sudo dhclient eth0 doesn't show a IP address assigned.
Resolution
Reboot the router. If that does not fix the issue then verify switches between the test machine and the router are powered on and working correctly.
One or more internal services down
Symptoms
External websites work, an internal website or multiple internal websites do not work.
Resolution
This has generally been caused by a VM server locking up: Check the console of fir, teak and elm. If one of them is saying something about a call trace and/or process blocked then that system is locked up. Ideally copy down the information on the screen and then reboot it.
Installations unable to find apt.shop.lan
Symptoms
During installation an error pops up saying unable to connect to apt.shop.lan or such
Resolution
- Log in to alder
- run: sudo service apt-cacher-ng restart
Occasionally this service crashes and needs a manual boot.
No incoming calls
Symptoms
People are unable to call in to Free Geek. Outgoing calls may still work. running sudo asterisk -vr on copper.shop.lan and then sip show peers does not show an IP address beside TrunkPrimary/...
Resolution
This is generally caused by our registration timing out with our provider, to fix:
- ssh copper.shop.lan
- sudo service asterisk restart
This could also be caused by the phones which usually ring being turned off or frozen.
External Web sites down
Symptoms
People from the outside unable to access Free Geek such as wiki.freegeekvancouver.org or tasks.freegeekvancouver.org Error 502 Bad Gateway nginx
Resolution
- ssh nut.shop.lan
- sudo service nginx restart or stop and start
