Dynamic UDP in BIND 9.1.0

Jim Reid jim at rfc1035.com
Fri Feb 16 19:10:25 UTC 2001


>>>>> "Karl" == Karl Lovink <karl at lovink.net> writes:

    Karl> When investigating the open ports in a firewall. I saw named
    Karl> uses the wellknown ports 53 TCP and UDP. But is also uses a
    Karl> random high UDP port. Can somebody explain me for what
    Karl> purposes BIND is these ports.

It's the source port for the queries the server sends to other name
servers. The query-source option can be used to make the name server
use a fixed port number if you have to keep the firewall happy.


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