Bind won't accpet request on UDP

Issues related to configuring your network
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mghe
Posts: 762
Joined: 2015/11/24 12:04:43
Location: Katowice, Poland

Bind won't accpet request on UDP

Post by mghe » 2020/12/04 07:48:44

Dear Team,

Bind won't accept request on port 53 UDP protocol, on TCP is fine.
I enabled it on firewalld but it don't mater, because it same if firewalld is disable.
Bind listening on port 53 UDP on server. There isn't other services listening on port 53 UDP on server.
I can dig from server on port 53, UDP and TCP protocols both local and external IP.
I can dig from outside server on port 53, TCP protocol.

But I can't dig from outside server on port 53 UDP protocol.



result scan nmap form outside server port 53 UDP protocol:

Code: Select all

PORT   STATE         SERVICE
53/udp open|filtered domain
I still looking for a solution.

CidiRome
Posts: 5
Joined: 2020/12/02 13:33:09

Re: Bind won't accpet request on UDP

Post by CidiRome » 2020/12/04 13:03:02

Hi.

I'm not an expert but that is strange...
If there are not iptables* firewall rules left when you stop firewalld it would only leave acl problems in the named.conf, but it wouldn't justify working on tcp and not on udp...

* assuming iptables is in use on your system and not nftables.

Cheers.

mghe
Posts: 762
Joined: 2015/11/24 12:04:43
Location: Katowice, Poland

Re: Bind won't accpet request on UDP

Post by mghe » 2020/12/17 07:14:28

Problem solved, ISP block port :evil:

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