[CentOS] nmap showing lots of ports open that shouldn't be

Sun Feb 12 20:17:08 UTC 2006
jim at datamantic.com <jim at datamantic.com>

I have a  CentOS 4.2 machine. lokkit shows that a firewall is  
enabled, and it is customized to allow SSH, Web, and DNS traffic only.

But if I run nmap against the server IP (from my home machine,  
outside the local network) it shows over 1000 open ports. Am I not  
understanding nmap, or is there something seriously wrong here?

Here is a small snip of the nmap output (I can include it all if that  
is helpful, but it is quite long):

(The 202 ports scanned but not shown below are in state: closed)
1/tcp     open  tcpmux
2/tcp     open  compressnet
3/tcp     open  compressnet
4/tcp     open  unknown
5/tcp     open  rje
6/tcp     open  unknown
7/tcp     open  echo
8/tcp     open  unknown
9/tcp     open  discard
11/tcp    open  systat
12/tcp    open  unknown
13/tcp    open  daytime
14/tcp    open  unknown
15/tcp    open  netstat
16/tcp    open  unknown
17/tcp    open  qotd
20/tcp    open  ftp-data
22/tcp    open  ssh
24/tcp    open  priv-mail
25/tcp    open  smtp
26/tcp    open  unknown