arp listing vanishes from cache at my ISP - virtual domain fails; native domain is OK!

arp listing vanishes from cache at my ISP - virtual domain fails; native domain is OK!

Post by Michael Kirschne » Thu, 15 Mar 2001 09:57:12



This is very weird: I have a linux box based on RedHat 7 which hosts an IP
based virtual domain in addition to the native domain; the machine is on the
end of a DSL line. All functions of the native domain (apache, sendmail,
ssh, etc.) work fine. All functions of the virtual domain (apache, sendmail)
were working up until Sunday. Then it just stopped working! I made no
changes to the system at all! Monday I find I'm getting no e-mails, I can't
reach the virtual domain from the outside world (but can from other machines
on the same side of the DSL line). My ISP says that my IP address for the
virtual domain doesn't appear in their arp cache (and never did!)! How can
this be? It worked before!!! Also, I can't ping my ISP's gateway with the
virtual domain's IP address but can with the native domain's IP address
(which I guess is what you'd expect if the gateway has no listing of my IP
and hardware address in it's arp cache).

Has anyone seen this before? Does anyone have a solution?

Thanks,
Mike

 
 
 

arp listing vanishes from cache at my ISP - virtual domain fails; native domain is OK!

Post by Michael Kirschne » Thu, 15 Mar 2001 12:40:07


I asked my ISP to hardwire the MAC address of my ethernet card into their
router...that solved the problem...until I change cards!


Quote:> This is very weird: I have a linux box based on RedHat 7 which hosts an IP
> based virtual domain in addition to the native domain; the machine is on
the
> end of a DSL line. All functions of the native domain (apache, sendmail,
> ssh, etc.) work fine. All functions of the virtual domain (apache,
sendmail)
> were working up until Sunday. Then it just stopped working! I made no
> changes to the system at all! Monday I find I'm getting no e-mails, I
can't
> reach the virtual domain from the outside world (but can from other
machines
> on the same side of the DSL line). My ISP says that my IP address for the
> virtual domain doesn't appear in their arp cache (and never did!)! How can
> this be? It worked before!!! Also, I can't ping my ISP's gateway with the
> virtual domain's IP address but can with the native domain's IP address
> (which I guess is what you'd expect if the gateway has no listing of my IP
> and hardware address in it's arp cache).

> Has anyone seen this before? Does anyone have a solution?

> Thanks,
> Mike