[Leaplist] port inquiry fedora 5 boxen

[doug jones]

all,

I've been given access to a headless fedora box at a customer site with which
to experiement with from my office (via ssh).  It's fedora 5 and I don't know
details of install other than it would have been a simple one (firewall would
have one of their simple settings {low/medium/high, on/off} ).  

I'm playing with C code examples of sending and receiving udp packets.  I've
got my receiving code running on the fedora in question and transmitting code on
another remote box.  The remote box transmits a udp packet and I'm hoping to the
receive the udp packet at the fedora box in question.  I'm using remote boxes
for both ends because they both have static IPs and I can use hardcoded
IPs in the C code and not have to figure out DHCP stuff yet.

I can tell by using tcpdump that the udp packet gets to the fedora box but
it doesn't make it to the user space code (or even if I compile and run it
as root).  Since I know the packet makes it to the destination, I figure I
have a firewall issue.  

My question is, how do I determine what ports are allowed by whatever firewall
may exist on the fedora box.  I'll be doing whatever tweaking thru a ssh login
so no gui tools.  Also, I remembered something about nmap from long ago 
experiements and see that nmap is NOT on the fedora box (and I don't know how
to use YUM yet).  Are there other command line tools to determine if a 
particular port is usable?

I guess a very good thing to know is whether or not tcpdump is _after_ the 
firewall.  If it is, then I've probably just got a code problem.

Doug Jones
-- 
penguin accomplice

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