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d dsDNS Problem with source and destination port is same

cisco20
cisco20 asked
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Last Modified: 2013-12-23
Having an issue with d ns not resolaving properly.
Used Wwireshark to capure packets and noticed that source and destination port were the same.(53) Has anyone seen this problem ? shouldnt one be a random port.
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Top Expert 2011
Commented:
Here is how a DNS query works in the context of your question.

Request -- client (random port >1023) -> server port 53
Reply -- server port 53 -> client (same port >1023 that request was sent from)


If your nameserver is recursive and the query result tells your nameserver to ask a different nameserver for the actual result, then that will be UDP 53 <-> UDP 53.

Author

Commented:
I'm seeing a bunch of queries but no responses ?

On a wireshark capture

source is the client ip 192.168.10.20
destination is telco public dns host 63.241.156.107

udp source port (53), dst port (53)

is this correct ?
Top Expert 2011
Commented:
As I explained, requests from the client should be coming from ports >1023.
Top Expert 2011

Commented:
Hi, is this still an issue?
Commented:
Problem was firmware issue on client side. Thanks.

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