Middlebury

Network Troubleshooting - Windows

Revision as of 08:33, 25 July 2008 by Christopher Hunt (talk | contribs) (Added midd_secure section)

midd_secure

If user can't connect to midd_secure:

  • Does the connection repeatedly ask for the user's credentials? Check whether user can get onto webmail. If not, might be using wrong PW/UN or account could be locked out. Try logging on to Novell.

Common error messages

  • "Trust relationship with server could not be established." The computer likely needs to be re-added to the domain or needs its name checked. Usually this message will only happen with lab computers, which are under DeepFreeze so we can't make any meaningful changes - Networks will have to deal with it. Get any information you can think of (Is it just one computer, or all in a specific area? MIDD numbers? Does it go away on restarting?) and assign to SR.

General network troubleshooting steps

  • Run ipconfig then look for the message under “Media State” (if there is one) and check IP addresses[1].
  1. Message: “Media is disconnected” – NIC[2] thinks it’s unplugged. Possible solutions:
    1. Loose cable (“ensure that both ends of the cable are firmly connected”)
    2. Wrong jack (red jack or “Data” jack = GOOD; blue jack is turned OFF, usually)
    3. Bad cable (try a different cable), bad jack (try another jack or connect another computer to the original jack), bad network card (invite customer to LIB202)
  2. See below what some IPs may indicate. In ANY case, here are some generic steps to try:
    1. [ ipconfig /release followed by ipconfig /flushdns and ipconfig /renew ] [3]
    2. Disable the connection in Control Panel, wait 5 seconds, re-enable it.
    3. Unplug jack, wait 5 seconds, plug back in. Doesn’t help? - Reboot.
    4. Try disabling 3rd party firewall software (e.g. Norton, McAfee, etc. may interfere with our network). Also, check to see if the browser has a proxy server configured.

If you still can't resolve the issue after these steps, get some information from the customer:

  • Name and location (building, room #). Make sure we have their extension or cell #.
  • Jack ID (it’s on a silver or white tag around or ON the jack, e.g. “A-0-12”).
  • The customer then should run ipconfig /all and tell you the message under “Media State” (if there is one), the IP address, Physical (aka MAC) address and the DHCP server address.
  • Customer should ping the DHCP server address, run arp -a and tell you the output of arp.
  • Record all of the above and create a ticket for SR.

What IP addresses mean

  1. 140.233… Computer should have a normal connection. Not working? Try b), above.
  2. 172.17… - registration, 172.19… - penalty or 172.18… - quarantine – search http://kb for steps to take[4].
  3. 169…. Computer can’t find our DHCP server, try all the steps under a) and b)
  4. 192… or 10… (BAD addresses for on-campus, may be OK for off-campus, see footnote[5]). May indicate a manual IP address or rogue DHCP server. Set the computer to obtain an IP address automatically, then release/renew. If it still gets a 192… or 10… IP address, there may be a rogue DHCP server in that subnet/area. See 2. below.
  5. Any other messages from ipconfig (not listed above) may indicate a problem with the Ethernet card. Invite the customer to LIB202.



  1. Make sure they’re looking at the “Ethernet Adapter Local Area Connection” (i.e. the WIRED Ethernet card, NOT the wireless).
  2. NIC = Network card
  3. In Vista, run those commands with admin privileges (Start -> type “cmd” in search box -> right-click “cmd” in search results).
  4. 172.16… - midd_secure. 172.20… - midd_unplugged.
  5. Some off-campus college houses are supposed to have 192 or 10 addresses. Search http://kb for a list of off-campus locations.