Re: Problem on Looback (127.0.0.1)

From: Neil Horman (nhorman_at_rNeOdShPaMt.com)
Date: 12/08/03 

Date: Mon, 08 Dec 2003 11:25:15 -0500

James News wrote:
> Hey Folks.
>
> Got a weird one. (I think, anyway.)
>
> Running RedHat 9 (2.4.20-24.9)
>
> I've got a problem with no traffic being allowed on the loopback (127.0.0.1)
> interface. As part of troubleshooting I've installed an Accept-All iptables
> policy, as well as turned off the iptables service but the results are the
> same.
>
> The interface is defined. ifconfig shows that.
> I am able to ping 127.0.0.1.
> There is a valid entry in the hosts file for localhost.localdomain.
>
> Sendmail (used only locally) is queuing up boat loads of mail all of which
> claim the connection was refused in 127.0.0.1
> Attempted to ssh 127.0.0.1 - that reports, "ssh_exchange_identification:
> Connection closed by remote host"
> I don't see anything in syslog that would designate an error related to
> attempted connections. When the firewall is running all connections are
> 127.0.0.1 are 'ACCEPTED'.
>
> Any ideas about what could be blocking traffic on loopback?
> ...or am I looking in the wrong place?
>
> Suggestions?
>
> Thanks.
Its also entirely possible that you have sendmail and ssh configured to
not accept connections from the loopback interface. Try going through
those configs to see if there are any interface restrictions set.

HTH
Neil 

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