Elam Daly wrote:
gforte wrote:
With all (un)due respect, your ISP is probably full of crap. Your tcpdumps
indicate that your UDP connections to the DNS servers are getting through,
at the least. That's why you're able to resolve hostnames. The fact that
your TCP syns never get responded to suggest that they are being blocked
someplace. If the server is not running any firewall as you say, then the
only other logical place is at the border router.
-g
Does DNS resolve names through UDP? Would that explain why I can't telnet
to port 53 on the DNS servers,yet still get name resolutions? Am I wrong conceptually
on how DNS works?
Thanks
Elam
YES, and YES DNS service uses UDP, Telnet is TCP
However, there still appears to be a TCP block. If you look at /etc/services you see port 53 is defined as domain for both TCP and UDP.
