Netstat Question

Hi All,

I'm fairly new to Linux. I had a Red Hat server running fine as it was
set up for me. It was acting as a mail/web server and worked
perfectly.

I build a new server and installed CentOS. However, I cannot get
Postfix to run properly on this server. I cannot find any issues,
however, the output of netstat -atn is different between the two
servers.

Maybe someone can look at the output and direct my where to look? It
would be much appreciated.

Output of Red Hat 9.0 server, which works fine:

tcp 0 0 0.0.0.0:32768 0.0.0.0:*
LISTEN
tcp 0 0 127.0.0.1:32769 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:993 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:3306 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:110 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:143 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:111 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:80 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:6000 0.0.0.0:*
LISTEN
tcp 0 0 127.0.0.1:631 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:25 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:443 0.0.0.0:*
LISTEN


Output of CentOS server, which is not working:

tcp 0 0 0.0.0.0:3306 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:907 0.0.0.0:*
LISTEN
tcp 0 0 127.0.0.1:783 0.0.0.0:*
LISTEN
tcp 0 0 0.0.0.0:111 0.0.0.0:*
LISTEN
tcp 0 0 127.0.0.1:631 0.0.0.0:*
LISTEN
tcp 0 0 127.0.0.1:25 0.0.0.0:*
LISTEN
tcp 0 0 :::993 :::*
LISTEN
tcp 0 0 :::995 :::*
LISTEN
tcp 0 0 :::110 :::*
LISTEN
tcp 0 0 :::143 :::*
LISTEN
tcp 0 0 :::80 :::*
LISTEN
tcp 0 0 :::443 :::*
LISTEN

Thanks in advance.......

In comp.os.linux.networking amerar@iwc.net <amerar@iwc.net>:
> Hi All,

> I'm fairly new to Linux. I had a Red Hat server running fine as it was
> set up for me. It was acting as a mail/web server and worked
> perfectly.

> I build a new server and installed CentOS. However, I cannot get
> Postfix to run properly on this server. I cannot find any issues,
> however, the output of netstat -atn is different between the two
> servers.

Why would you want to use postfix? There are 2 excellent MTA
coming with your distribution, sendmail + exim.

> Maybe someone can look at the output and direct my where to look? It
> would be much appreciated.

> Output of Red Hat 9.0 server, which works fine:

> tcp 0 0 0.0.0.0:25 0.0.0.0:*
> LISTEN

Listening to anyone on port 25.

> Output of CentOS server, which is not working:

> tcp 0 0 127.0.0.1:25 0.0.0.0:*
> LISTEN

Only listening on localhost, a 'telnet localhost 25' on the box
should connect you to whatever is running on port 25, usually
some MTA.

That is the problem you need to fix, however for easier staying
in line with updates. I'd use one of the two MTA coming with
RHEL/CentOS and decide up on the purpose of the machine which one
to use.

Good luck

--
Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
mail: echo zvpunry@urvzvat.qr | perl -pe 'y/a-z/n-za-m/'
#bofh excuse 296: The hardware bus needs a new token.

Michael Heiming wrote:
> In comp.os.linux.networking amerar@iwc.net <amerar@iwc.net>:
> > Hi All,
>
> > I'm fairly new to Linux. I had a Red Hat server running fine as it was
> > set up for me. It was acting as a mail/web server and worked
> > perfectly.
>
> > I build a new server and installed CentOS. However, I cannot get
> > Postfix to run properly on this server. I cannot find any issues,
> > however, the output of netstat -atn is different between the two
> > servers.
>
> Why would you want to use postfix? There are 2 excellent MTA
> coming with your distribution, sendmail + exim.
>
> > Maybe someone can look at the output and direct my where to look? It
> > would be much appreciated.
>
> > Output of Red Hat 9.0 server, which works fine:
>
> > tcp 0 0 0.0.0.0:25 0.0.0.0:*
> > LISTEN
>
> Listening to anyone on port 25.
>
> > Output of CentOS server, which is not working:
>
> > tcp 0 0 127.0.0.1:25 0.0.0.0:*
> > LISTEN
>
> Only listening on localhost, a 'telnet localhost 25' on the box
> should connect you to whatever is running on port 25, usually
> some MTA.
>
> That is the problem you need to fix, however for easier staying
> in line with updates. I'd use one of the two MTA coming with
> RHEL/CentOS and decide up on the purpose of the machine which one
> to use.
>
> Good luck
>
> --
> Michael Heiming (X-PGP-Sig > GPG-Key ID: EDD27B94)
> mail: echo zvpunry@urvzvat.qr | perl -pe 'y/a-z/n-za-m/'
> #bofh excuse 296: The hardware bus needs a new token.

I'd take your advice on the mail program, but my entire application is
build around Postfix, not sendmail.......so, I'm gonna stick with
Postfix. Fixed the problem with port 25 listening on 127.0.0.1
only.......

Kind of curious what the 3 colons (:::) mean though......that looks
strange......

Hello,

amerar@iwc.net a écrit :
>
> Kind of curious what the 3 colons (:::) mean though.

Just as in the other lines, it means address "::" followed by a colon
and a port number. "::" is the short form of the IPv6 address
0:0:0:0:0:0:0:0 which means ANY. It is the equivalent of IPv4 0.0.0.0.
Note that by default Linux IPv6 sockets also accept IPv4 communications.