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Old 10-27-2004, 02:12 PM   #1
mwmethe
LQ Newbie
 
Registered: Jun 2001
Location: Southwest New Hampshire
Distribution: Mandrake, RedHat
Posts: 22

Rep: Reputation: 15
2.4.20-8 port 25 closed, cant open


Hello All,

Redhat 9 box running apache, postfix, few other things. When I nmap my local box, I am told:

Port State Service
22/tcp open ssh
25/tcp open smtp
80/tcp open http
111/tcp open sunrpc
631/tcp open ipp
6000/tcp open X11
8080/tcp open http-proxy
10000/tcp open snet-sensor-mgmt

When I nmap my domain from outside my lan I get:

PORT STATE SERVICE
20/tcp closed ftp-data
21/tcp closed ftp
25/tcp closed smtp
80/tcp open http
81/tcp open hosts2-ns
110/tcp closed pop-3
113/tcp closed auth
232/tcp open unknown
252/tcp closed unknown
3389/tcp open ms-term-serv
5901/tcp closed vnc-1
8080/tcp open http-proxy

Why do 21, 25 110 all show up as closed from the outside. I have verified that my ISP (RoadRunner) does not block 25. I cant figure this out. Even iptabes looks clean:

Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination

Chain OUTPUT (policy ACCEPT)
target prot opt source destination


Any help you guys can offer would be GREATLY appreciated. I am running out of hair.


Thanks

-=Mike M
 
Old 10-27-2004, 02:29 PM   #2
david_ross
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Registered: Mar 2003
Location: Scotland
Distribution: Slackware, RedHat, Debian
Posts: 12,047

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IS your smtp server listening on all interfaces?
netstat -nlp

Does your server have a public IP address or do you need to forward a port from a router or firewall? has this been done?

Where did you scan from? perhaps that location blocked outgoing access?
 
Old 10-27-2004, 02:47 PM   #3
mwmethe
LQ Newbie
 
Registered: Jun 2001
Location: Southwest New Hampshire
Distribution: Mandrake, RedHat
Posts: 22

Original Poster
Rep: Reputation: 15
Quote:
Originally posted by david_ross
IS your smtp server listening on all interfaces?
netstat -nlp

Does your server have a public IP address or do you need to forward a port from a router or firewall? has this been done?

Where did you scan from? perhaps that location blocked outgoing access?
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 3491/

I see that in the netstat -nlp output

IPCOP firewall is forwarding port 25 requests to 192.168.1.10

Scanned from my office and it is not blocked...

Thanks for the help so far
 
Old 10-27-2004, 03:32 PM   #4
david_ross
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Registered: Mar 2003
Location: Scotland
Distribution: Slackware, RedHat, Debian
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The 127.0.0.1 shows that the smtp server is only listening on the loopback - hence it is not going to be availble anywhere other than on the server itself.

You can configure this with the inet_interfaces directive:
http://www.postfix.org/postconf.5.html#inet_interfaces
 
Old 10-27-2004, 03:54 PM   #5
mwmethe
LQ Newbie
 
Registered: Jun 2001
Location: Southwest New Hampshire
Distribution: Mandrake, RedHat
Posts: 22

Original Poster
Rep: Reputation: 15
Got it!

Perfect. Thanks so much for the help.

Seems obvious.

Thanks again

-=mwm
 
  


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