FC-5 iptables question

[Peter Horst]

Sorry, kind of a dumb question.  I'm trying to open a port to allow DNS 
traffic (port 53, UDP and TCP).  I tried a quick nmap from outside my 
network, and though the tcp port shows up open, there's no reading from 
the udp port. How can I tell if I've opened the port correctly? Here's 
what I think is the relevant output from 'service iptables status' - 
does this look right?  Thanks much...

Chain RH-Firewall-1-INPUT (2 references)
num  target     prot opt source               destination
1    ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0
2    ACCEPT     icmp --  0.0.0.0/0            0.0.0.0/0           icmp 
type 255
3    ACCEPT     esp  --  0.0.0.0/0            0.0.0.0/0
4    ACCEPT     ah   --  0.0.0.0/0            0.0.0.0/0
5    ACCEPT     udp  --  0.0.0.0/0            224.0.0.251         udp 
dpt:5353
6    ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0           udp dpt:53
7    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp dpt:53
8    ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0           udp 
dpt:631
9    ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           tcp 
dpt:631
10   ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state 
RELATED,ESTABLISHED
11   ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state 
NEW tcp dpt:22
12   ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state 
NEW tcp dpt:25
13   ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state 
NEW tcp dpt:80
14   ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state 
NEW tcp dpt:443
15   ACCEPT     tcp  --  0.0.0.0/0            0.0.0.0/0           state 
NEW tcp dpt:53
16   ACCEPT     udp  --  0.0.0.0/0            0.0.0.0/0           state 
NEW udp dpt:53
17   REJECT     all  --  0.0.0.0/0            0.0.0.0/0           
reject-with icmp-host-prohibited