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troubleshooting:testing-dns-using-nslookup [2010-08-02 17:31:32]
garrett.plasky 		troubleshooting:testing-dns-using-nslookup [2010-08-02 17:41:21]
garrett.plasky
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 =====Interpreting Results===== =====Interpreting Results=====
-The first column, the hop count, represents the number of stops your information has made along the route to attempt to contact the other computer. The next three columns are the round-trip times in milliseconds for three different attempts to reach the destination. The last column is the name of the host that responded to the request.+Of particular interest to us is the //Address// field listed in the **Non-authoratative answer** section. This displays the IP that the domain name queried resolves to on the workstation locally. If the workstation is having DNS issues, this answer may come up blank.
  
-The above example shows a successful trace without any unreachable hosts. If your trace dies out after a specific hop by only returning full lines of asterisks ("* * * *"), then chances are the issue is at or just after the hop before the asterisks began. +If the domain's A record was recently updated the IP may be cached at the workstation's local resolver and the IP listed may differ from the new one. If this is the case, the PCs cache can be cleared forcing it to look to it's local resolver for the new record. This is done using the command //ipconfig /flushdns// from the same command prompt window the nslookup was run in. Note that this will only clear the workstation's cache and not the local DNS server(s), so if those have not been updated with the new record yet, this command will not have any effect.
- +
-Large jumps in response times can also mean a possible issue. If you are consistently seeing around 5ms for your first 3 hops, for example, and then on the 4th hop the response time jumps to 500ms, then there may be an issue with the 4th hop.+
  
 =====Sending Us the Results===== =====Sending Us the Results=====