[Sysadmin] Firewall Issue on cerf?

[William Anderson]

On Tue, Oct 18, 2016 at 5:17 PM, Dean Mah <dean.mah at gmail.com> wrote:
> Try sending an email to yourself from cerf and then take a look at
> /var/log/mail.log.
>
> You can also test SMTP connectivity out by telnetting to port 25 on an MTA
> server , i.e.,
>
> cerf> telnet tron.evolt.org 25
>
> you should be able to enter SMTP commands at that point through telnet and
> have the mail server respond.

It's fixed now.  There's something funky going on at the IPv6 layer
that was preventing proper DNS resolution (probably the v6 resolvers
in resolv.conf), so I've changed the precedence in /etc/gai.conf to
prefer IPv4 rather than IPv6 for everything.  You should have the test
emails you've sent yourself now as well.

Bloody v6.

-n