Difference between revisions of "Network Troubleshooting - Windows"

(New page: <center>'''Network Troubleshooting Reference for Windows'''</center> # Run ipconfig then look for the message under “Media State” (if there is one) and check IP addresses<ref name="f...)
m (Windows moved to Network Troubleshooting - Windows: Make name more descriptive.)
(No difference)

Revision as of 12:21, 11 July 2008

Network Troubleshooting Reference for Windows

  1. 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. Jack out, wait 5 seconds, jack 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.
    3. 140.233… Computer should have a normal connection. Not working? Try b), above.
    4. 172.17… - registration, 172.19… - penalty or 172.18… - quarantine – search http://kb for steps to take[4].
    5. 169…. Computer can’t find our DHCP server, try all the steps under a) and b)
    6. 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.
    7. Any other messages from ipconfig (not listed above) may indicate a problem with the Ethernet card. Invite the customer to LIB202.
  1. If you reach f) and you still haven’t resolved the issue, get the customer’s:
    1. Name and location (building, room #). Make sure we have their extension or cell #.
    2. Jack ID (it’s on a silver or white tag around or ON the jack, e.g. “A-0-12”).
    3. 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.
    4. Customer should ping the DHCP server address, run arp -a and tell you the output of arp.
    5. Record all of the above and create a ticket for SR.
  1. Rogue Servers and entire building losing connectivity:
    1. Talk to someone in SR immediately. Still make tickets assigned to SR.
    2. If this happens after 5pm, check “SNS After Hours” (it’s a Public Folder/Calendar in Outlook) and call the person listed there. Be prepared to give all the information you would put in a ticket. Still make tickets and indicate that you have contacted someone, if that’s true.
    3. Note that one person calling with connection issues doesn’t mean the whole building is down. Ask the customer if anyone else is having the same issue. Generally we need a few calls to consider the issue to be building wide.

  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.