Network issues - potentially DNS?
Posted on 2010-11-25
Trying to do some trouble shooting here.... Office with two servers running SBS2003 - one the main server is primary DC, DNS server etc.... the other runs Exchange 2003.
Internet provided by Telco (Cisco modem); Firewall is Fortinet 80C.
Approximately 60 users in the office
For the last four or five days users have been experiencing what looks like a loss of internet connectivity - in particularly the connection to the Exchange server has been dropping or very slow. Browsers seem to have slow connections or can't "connect" to some sights.
At first since both preferred and alternate DNS where our ISPs I assumed potentially a problem with their DNS servers and set our alternate DNS to a public Google DNS server.
Nothing in the event logs is raising flags with me but pinging our gateway from either server yields mixed results (main server is better - with three out of four or four out of four connections most of the time).
Trying to ping our main server from the Exchange server however is showing mostly 1 or 2 out 4 ping transactions completing successfully most of the time.
Any ideas? Am I looking at a DNS issue (and where do I start digging?) or could it be something as simple as a failing NIC or faulty ethernet cable on one of the boxes?
I'm open for suggestions.....!