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Basically this is whats going on, I have an external SSH connection into a system running Ubuntu 12.04 desktop. However I have no external connection from that PC to the internet, to run apt-get or ping. I can however resolve IP addresses, the Ping command will correctly return the IP addresses of target hostnames.

From what their network guys tell me there shouldn't be anything on the router or server that stopping this PC from connecting out. My understanding of how their network is setup is that the server handles the firewall, DNS and internet connection, while the router is used for internal routing, the Server is on IP address 192.168.0.1 and the router is on 192.168.0.254, with the PC being 192.168.0.19.

I've tried doing a traceroute, after manually installing it, and it doesn't appear to get anywhere, not even to the local network first, which does reply to pings.

ifconfig

eth0      Link encap:Ethernet  HWaddr 54:04:a6:02:04:20  
          inet addr:192.168.0.19  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::5604:a6ff:fe02:420/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:10061 errors:0 dropped:0 overruns:0 frame:0
          TX packets:7793 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1564415 (1.5 MB)  TX bytes:1254821 (1.2 MB)
          Interrupt:46 Base address:0xe000 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:40916 errors:0 dropped:0 overruns:0 frame:0
          TX packets:40916 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:4393568 (4.3 MB)  TX bytes:4393568 (4.3 MB)

route -n

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.0.254   0.0.0.0         UG    0      0        0 eth0
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eth0
192.168.0.0     0.0.0.0         255.255.255.0   U     1      0        0 eth0

traceroute to my ip address

traceroute to ... (...), 30 hops max, 60 byte packets
 1  * * *
 2  * * *
 3  * * *
 4  * * *
 5  * * *
 6  * * *
 7  * * *
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16  * * *
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19  * * *
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23  * * *
24  * * *
25  * * *
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30  * * *

external traceroute to PC

traceroute to ... (...), 30 hops max, 60 byte packets
 1  dsldevice.lan (192.168.1.254)  16.894 ms  16.555 ms  16.287 ms
 2  lo0-central10.pcl-ag05.plus.net (195.166.128.186)  17.580 ms  18.230 ms  24.675 ms
 3  link8-central10.pcl-gw02.plus.net (84.93.249.142)  32.715 ms  33.488 ms  34.399 ms
 4  xe-8-2-0.pcl-cr02.plus.net (212.159.1.10)  34.976 ms  35.439 ms  35.909 ms
 5  ae1.ptw-cr02.plus.net (195.166.129.2)  36.818 ms  38.005 ms  39.118 ms
 6  ae2.ptw-cr01.plus.net (195.166.129.4)  39.596 ms  29.893 ms  30.118 ms
 7  xe-0-1-1.jprg-01.thn.uk.mdnx.net (195.66.224.33)  25.884 ms  16.471 ms  17.008 ms
 8  xe-0-0-1.jar-004.thn.uk.mdnx.net (135.196.65.114)  15.459 ms  16.204 ms  17.875 ms
 9  ge-6-0-0.core-02.tlh.uk.mdnx.net (135.196.69.94)  19.085 ms  19.727 ms  20.382 ms
10  gi4-0-105.resellers.erx-001.egh.uk.mdnx.net (135.196.154.46)  22.704 ms  23.290 ms  24.031 ms
11  92.54.178.213 (92.54.178.213)  41.196 ms  42.174 ms  33.699 ms
12  * * *
13  * * *
14  * * *
15  * * *
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/etc/network/interfaces

auto lo
iface lo inet loopback

/etc/hosts

127.0.0.1   localhost
127.0.1.1   TM-SCADA
192.168.0.19    TM-SCADA

# 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

/etc/resolv.conf

nameserver 192.168.0.1
nameserver 127.0.0.1
search sbserver.welland.local

Any ideas, or anything I've overlooked?

share|improve this question
You say My understanding of how their network is setup is that the server handles the firewall, DNS and internet connection, while the router is used for internal routing, however your route -n output shows that the PC is trying to use the router (182.168.0.254) for all traffic rather than the server (192.168.0.1). Have you tried adding a default route to the server? – StarNamer Aug 21 '12 at 10:56
Yes, most of the time if I do that it takes out my external connection and won't let me back in (I have a dial up modem connection I can use to revert changes that break the internal network though). The first time I did it though it took my connection out for a while then let me back in later. Basically their network management company told me the firewall was on the server and that the server address was 192.168.0.1, however dhcp provides 192.168.0.254 as the default gateway. – Skid Aug 21 '12 at 10:59
I no longer need help with this issue, I required the outbound connection to perform a system update, so we simply moved the computer to another network and did the update from there. – Skid Aug 23 '12 at 9:07

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