Question : Problem: swapped switches in office, now DNS lookups are very slow

I recently swapped a switch with another switch in the office.  The #1 switch was loud... I wanted to get it in another location that is more enclosed while I get some fans ordered for it.  I did a swap between location #1 and #2.

Now my DNS lookups are very slow.  I have reset all three switches, upgraded the firmware to most recent versions... when I do a firmware backup to my laptop it is giving me 5k... this is coming from the switch directly to the laptop through a cat5 cable!

All I did was swap two switches in the office... what could be causing this?  I have flushed arp caches on our firewall and on the server.  I see no way to flush the arp cache on the switches themselves (nice huh?).

These are DLINK DGS1248t switches.  Thanks.

Answer : Problem: swapped switches in office, now DNS lookups are very slow

I had 4 forwarding servers specified on my DNS server.  I decided to try connecting to them and doing DNS lookups... 2 of the 4 timed out when using them for lookups.  They were the two at the top of the forwarding list.  I removed them from the list and now the internet is fast again.

I have no idea why this worked faster when the DNS server was plugged into a different switch... but after swapping the switches this problem became apparent but it looks like the problem was on the DNS server... not the switch.