SMTP

[jln]

Hi everyone,

I have a problem with sendmail on a fedora distribution.
It was working but not anymore.

==========
[root@ns sbin]# ip6tables --list
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

[root@ns sbin]# lsof -i TCP:25
COMMAND    PID USER   FD   TYPE   DEVICE SIZE/OFF NODE NAME
sendmail 30654 root    4u  IPv4 30418180      0t0  TCP *:smtp (LISTEN)
sendmail 30654 root    6u  IPv6 30418182      0t0  TCP ns.stben.net:smtp (LISTEN)
sendmail 30654 root    7u  IPv6 30418183      0t0  TCP router.stben.net:smtp (LISTEN)
[root@ns sbin]# telnet 2001:470:792a::108 25
Trying 2001:470:792a::108...
telnet: connect to address 2001:470:792a::108: Connection refused
==========

I did it from the machine connected to internet.
That machine has 2 interfaces p3p1 [2001:470:792a::108/212.68.197.108] connected to internet
and p1p1 [2001:470:792a:1::1/10.149.85.30] connected to my internal net.
http://www.stben.net/phpsysinfo/

I can't find out what was gone wrong.
Could you help please?

Thanks.

Bye,
Jean-Louis

[jln]

Everything is all right now!
A misconfiguration.

sendmail.cf
==========
O DaemonPortOptions=Name=IPv6, Addr=2001:470:792a::108, Family=inet6
==========
I changed the IP address of the interface and forgot to change it in sendmail.cf!

[snarked]

OK, but is there a reason why you bind to a specific IPV6 address instead of "IPv6_Any" ("::")?  I find it more efficient to let sendmail bind to the wildcard address and let the firewall determine which IPv6 addresses are valid incoming destinations.

[jln]

If you look how sendmail reacts under ipv6 (my first post) it's not the same
than in ipv4.
ipv4 has only one bind.
ipv6 one bind for each interface.

[snarked]

It doesn't act that way for me.  I compile a custom kernel from the source at ftp.kernel.org.

[jln]

I use a standard Fedora (release 20).
Do you change sendmail.mc or sendmail.cf?

[kriteknetworks]

I attempted to connect, worked fine.

telnet 2001:470:792a::108 25                                                                       
Trying 2001:470:792a::108...
Connected to ns.stben.net.
Escape character is '^]'.
220 ns.stben.net ESMTP Sendmail 8.14.8/8.14.5; Sun, 6 Apr 2014 16:30:38 +0200

[jln]

Sure!
Everything is fine now. 8)

[snarked]

I use a sendmail.mc file and compile it through the M4 processor into a .cf file.  However, that shouldn't make a difference at all.

You don't need two IPv6 sockets - using an IPv6_addr_any (::0) socket will save one and do the same thing, and this also works for IPv4 (at least on my kernel):

DAEMON_OPTIONS(`Name=MTA, Family=inet6, Modifier=AEbf,Port=smtp')dnl

You may also want to enable this for local submissions:

DAEMON_OPTIONS(`Name=MSA, Family=inet6, Modifier=Eau, Port=submission')dnl

And such results in these open "files" (others deleted):

sendmail    993     root    4u     IPv6               6962          0t0        TCP *:submission (LISTEN)
sendmail    993     root    6u     IPv6               6964          0t0        TCP *:smtp (LISTEN)

[jln]

Could you post the line generated please?
Thanks.

[snarked]

O DaemonPortOptions=Name=MSA, Family=inet6, Modifier=Eau, Port=submission
O DaemonPortOptions=Name=MTA, Family=inet6, Modifier=AEbf,Port=smtp

[jln]

Thank you!