can't ping outside own network on ns1

["justin cunningham" <jcunningham@engine8.com>]

Hi, I don't understand why I cant ping outside my own network on my
primary nameserver.  I called the isp and according to them there's no
problem with connectivity (they always say that).  I also have a web,
mail and db server (all running potato) all of which I can reach the
outside but not the primary nameserver.  The only thing I've done
recently on the servers is apt-get update but if I had a broken package
I'd told me.  Syslog shows normal activity.  I also have apache running
(I use as a dev space for the www sites) and there all reachable via
http.  I can get to the server via ssh (with some latency).   Any ideas
on the cause of this?

Can:  reach locahost, gateway, external ip, ips in same range via name
and ip

Can't:  reach external sites like yahoo, provider's ns1 via ip nor apt
source.lists

Ps aux shows bind, apache, et al running.  I edited resolv.conf and
swapped nameservers with isp's= no change.

My nameserver is the authoritative for the sites et al while the isp is
the reverse lookup authoritative.  Could they have misdocumented my ips
ptr records for the reverse lookup?  

Thanks for any help on this, Justin