how to listen to port 53 (DNS)

[=?ISO-8859-1?Q?Daniel_G=F3mez?=]

hello,

I am trying to listen to port 53 on localhost in order to read the
received information and then forward it to another host (a DNS server)
on port 53. I have therefore written:

ServerSocket listen = new ServerSocket(53);
Socket data = listen.accept();

I have changed DNS server configuration to 127.0.0.1, so that all DNS
queries should arrive here. But when I try to access to an URL, so that
a DNS query is generated, nothing happens. I cannot hear anything on
port 53.

What am I doing wrong?

thank you.

 

[Mark Thornton]

hello,

I am trying to listen to port 53 on localhost in order to read the
received information and then forward it to another host (a DNS server)
on port 53. I have therefore written:

ServerSocket listen = new ServerSocket(53);
Socket data = listen.accept();

I have changed DNS server configuration to 127.0.0.1, so that all DNS
queries should arrive here. But when I try to access to an URL, so that
a DNS query is generated, nothing happens. I cannot hear anything on
port 53.

What am I doing wrong?

thank you.

DNS queries are usually done using datagrams and not via sockets
(although I seem to remember that both are permitted). I'm assuming that
your operating system allows you to listen on port 53 (Windows will,
other OS may require appropriate permissions).

Mark Thornton

 

[=?ISO-8859-1?Q?Daniel_G=F3mez?=]

yes, I am using W2000. Shall I use DatagrammSocket instead?

Daniel

 

[Mark Thornton]

yes, I am using W2000. Shall I use DatagrammSocket instead?

Daniel
Yes.