DNS stops working in between.

Hi,
i have setup DNS (BIND 9.*) server on Linux 9.0.
It works fine.
When i give command on commnad prompt. :
###################

[root@shn root]# dig networkshastrihall.com

; <<>> DiG 9.2.1 <<>> networkshastrihall.com
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 62500
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 0

;; QUESTION SECTION:
;networkshastrihall.com. IN A

;; ANSWER SECTION:
networkshastrihall.com. 20064 IN A 202.63.167.192

;; AUTHORITY SECTION:
networkshastrihall.com. 20064 IN NS ns2.networkshastrihall.com.
networkshastrihall.com. 20064 IN NS ns1.networkshastrihall.com.

;; Query time: 6 msec
;; SERVER: 202.63.164.17#53(202.63.164.17)
;; WHEN: Fri Apr 30 09:21:27 2004
;; MSG SIZE rcvd: 92

################

It semms with result it works fine with no error.
When I try to access "www.networkshastrihall.com" from It displays error page not found. Not able to locate problem whether it is DNS prob;lem OR apache problem.
Apache also works fine.

##########
[root@shn root]# /usr/local/apache2/bin/httpd -k restart

########
does not give any error.

Please tell me with above DNS and Apache is working properly OR not.

Thanks

TCP and UDP queries to port 53 on IP 202.63.167.192 time out. Please check your router and/or firewall settings.

Ya. It was firewall problem.
One more question.

I am forwarding port 53 tcp & udp to eth2. IP assigned to eth2 is 192.168.1.2. This case DNS works fine.
If I change IP address of eth2 to 192.168.1.1 from 192.168.1.2 and restart routing and DNS. This change will take effect immediatly OR it needs some time to activate with changed IP address?

Thanks for support.

If you're not changing the domain zone contents, then changes take effect immediately. If you do change domain zone contents, then changes may take a bit to take effect on resolver servers that have cached the old data - and take effect immediately for those that have not.