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Old 03-30-2009, 06:59 AM   #1
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Registered: Mar 2009
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Question Default Gateway not working ? (Ubuntu server)


I'm running the latest Ubuntu server version (intrepid), and have since a couple of weeks a strange problem.

I cannot reach the server anymore from the internet (i have port mappings in place). I also can't do a traceroute or ping on the shell to the internet:
root@hercules:~# uname -a
Linux hercules.domain.tld 2.6.24-21-xen #1 SMP Wed Oct 22 02:11:27 UTC 2008 i686 GNU/Linux
root@hercules:~# ifconfig
eth0      Link encap:Ethernet  HWaddr 9e:61:38:c7:07:e6
          inet addr:  Bcast:  Mask:
          inet6 addr: fe80::9c61:38ff:fec7:7e6/64 Scope:Link
          RX packets:1107993 errors:0 dropped:0 overruns:0 frame:0
          TX packets:713101 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:451206372 (451.2 MB)  TX bytes:197973608 (197.9 MB)

lo        Link encap:Local Loopback
          inet addr:  Mask:
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:5114 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5114 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:457520 (457.5 KB)  TX bytes:457520 (457.5 KB)

root@hercules:~# ping
PING ( 56(84) bytes of data.
From icmp_seq=1 Destination Port Unreachable
From icmp_seq=2 Destination Port Unreachable
From icmp_seq=3 Destination Port Unreachable
From icmp_seq=4 Destination Port Unreachable

--- ping statistics ---
4 packets transmitted, 0 received, +4 errors, 100% packet loss, time 2999ms

root@hercules:~# traceroute
traceroute to (, 30 hops max, 40 byte packets
 1  hercules (  0.359 ms  0.383 ms  0.390 ms
So ping doesn't work, and traceroute ends at himself ?
Below my hosts file and output of route and network config:
root@hercules:~# cat /etc/hosts       hercules.domain.tld localhost hercules     hercules.domain.tld hercules     w2003r2 w2003r2.domain.tld   Firewall

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
root@hercules:~# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface     *        U     0      0        0 eth0
default         Firewall         UG    0      0        0 eth0
root@hercules:~# cat /etc/network/interfaces
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet static
Strange thing is, updates with aptitude work fine, also lynx the CLI browser can access the Internet.

On my Firewall (it's the default gateway) i have rules in place that allow traffic from ANY to ANY, and all other PC's in the network can do ping/traceroute just fine.

Firewall logs:
2009-03-19 19:56:43	TCP PORT 8080	20 sec.	234	0	Close - AGE OUT
Please advise !
Old 03-30-2009, 08:15 AM   #2
LQ Newbie
Registered: Mar 2009
Posts: 7

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I forgot to mention: but all the other hosts on the local network have no troubles.

And another note, the Ubuntu is a virtualized OS on Xenserver 5 hypervisor. Altough i have a windows VM on it that works fine.


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