Re: networking problem
- From: noEMA <noEMA@xxxxxxxxxxxxxxxx>
- Date: Tue, 25 Apr 2006 20:20:29 -0400
On Tue, 25 Apr 2006 14:03:39 +0000, Beef wrote:
I have two computers. Sheaf (192.168.0.2) runs Mandriva 2006, Porter
(192.168.0.3) runs Ubuntu 5.10.
They are connected to a NetGear Wireless ADSL router (model DG834G)
(192.168.0.3), by ethernet cables.
I can ping from sheaf to porter, but not from porter back to sheaf.
Both machines can go through the router to the internet.
Here are the routing tables:
root@porter:~# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt
Iface 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0
0 eth0 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0
0 eth0 (netstat on porter doesn't list lo, but the interface is
configured OK)
[root@sheaf ~]# netstat -rn
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt
Iface 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0
0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0
0 lo 0.0.0.0 192.168.0.1 0.0.0.0 UG 0 0
0 eth1
I spent hours looking for traceroute on Ubuntu, before finding tracepath:
[root@sheaf ~]# tracepath porter
1: 192.168.0.2 (192.168.0.2) 0.348ms pmtu
1500 1: porter (192.168.0.3) 0.590ms
reached
Resume: pmtu 1500 hops 1 back 1
root@porter:~# tracepath sheaf
1: 192.168.0.3 (192.168.0.3) 0.437ms pmtu
1500 1: no reply
2: no reply
3: no reply
I think that the problem is with routing through the router, not really on
the computers themselves.
I tried creating static routes on the router from one machine to the
other, and this changed nothing.
Can anybody explain to me what is wrong, so I can fix it, please?
Beef.
Hi.
1 ) If I read your text correctly, you wrote that the DSL router address
is at 192.168.0.3.
But the routing table of both hosts are configured to go to 192.168.0.1.
I'll assume that it's only a typing mistake and your router is indeed
configured as 192.168.0.1.
If the DSL is indeed configured as 192.168.0.3, then you have an IP
address conflict. Both Porter and the DSL are at .3
2) Lets check the /etc/hosts file on each PCs.
Sheaf should look like :
# /etc/hosts
127.0.0.1 localhost.localdomain localhost
192.168.0.2 Sheaf.AnyDomain.AnyCountry Sheaf
192.168.0.3 Porter.AnyDomain.AnyCountry Porter
Now, Porter's /etc/hosts should also look like :
# /etc/hosts
127.0.0.1 localhost.localdomain localhost
192.168.0.2 Sheaf.AnyDomain.AnyCountry Sheaf
192.168.0.3 Porter.AnyDomain.AnyCountry Porter
3) If these files are the same, then I would look toward the "arp" command.
Install yourself in front of Porter's console.
Try to ping Sheaf :
$ ping 192.168.0.2
then :
$ /sbin/arp -a
(I hope to see something like the line below. NOTE: Ethernet adddress will
be different.)
? (192.168.0.2) at 01:02:03:04:05:06 [ether] on eth0
If we see something like that, then it's good sign. Ethernet cablings
and ports are Ok...
3) We might have a firewall on Sheaf which inhibit ping answers.
Check with :
# /sbin/iptables -L -n | grep icmp
I expect to see lines starting with ACCEPTs.
If not, then check the Firewall rules to allow answers to pings.
4) let's compare /etc/host.conf files on both servers
It should look more or less like this :
$ cat /etc/host.conf
order hosts, bind
Other advices :
1) When debugging, try to ping, traceroute and tracepath with numerical IP
addresses. You will not fail on name resolution problems.
Well, I hope it help...
.
- Follow-Ups:
- Re: networking problem
- From: Beef
- Re: networking problem
- Prev by Date: Re: Need tutorial for udev
- Next by Date: Re: DVD playing on FC5
- Previous by thread: Re: networking problem
- Next by thread: Re: networking problem
- Index(es):
Relevant Pages
|
