Did you tried to ping other host inside and outside your network, your gateway ?
If not working, did you tried to arping your gateway ?
Did you look for packet with "tcpdump -n -i eth0" ?
On 10/31/07, Shawn Everett <shawn@xxxxxxxxxx> wrote:
> Hi Guys,
>
> I'm 100% sure this is not a Linux issue but I want a second opinion...
>
> I have a Linux server running CentOS. It was been absolutely perfect
> without any errors or problems.
>
> Since Monday it has been unable to send email. It is configured to act as
> a smart host. All email gets forwarded to smtp.isp.net.
>
> The server is on a network behind a firewall completely nat'd. No ports
> are forwarded to it.
>
> telnet smtp.isp.net 25 generates the following:
> Trying a.b.c.d...
> Connected to smtp.isp.net.
> Escape character is '^]'.
>
> And then nothing. All other machines can connect to smtp.isp.net 25
> without a problem. They also use that host for their outgong mail server.
>
> Using links to surf the web has a similar result. It just hangs
>
> traceroute and nslookups work correctly.
>
> There are no errors anywhere.
>
> The network in question has various routing and vlan configurations, proxy
> servers and such. I tend to suspect they're the problem. They're also
> not in my control.
>
> The firewall does show the Linux box attempting to make SMTP connections
> but nothing else.
>
> Any ideas or suggestions would be appreciated. I have not yet rebooted the
> server.
>
> Shawn
> _______________________________________________
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> CentOS@xxxxxxxxxx
> http://lists.centos.org/mailman/listinfo/centos
>
--
Alain Spineux
aspineux gmail com
May the sources be with you
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