Suse 8.0: only the gateway can be reached over internal network
After a reboot I can no longer get any network connection over the LAN from/to a SuSE Linux server (SuSE Linux 8.0 Professional). The server has two NIC's. One to the internet (eth0) the other two the internal network (eth1). Only the internal network is affected. While I still can ping between the gateway and the server I cannot ping between any other PC and the server using the internal network. Using YAST2 I made some changes in the configuration, but I'm not aware of having changed anything specific to the network or security configuration (actually I added another partition and made changes to the time configuration; that's all I remember). The gateway is a Windows NT server. All internal computers are configured to use this same gateway. Only the SuSE Linux server is affected by the problem. The configuration worked for months with SuSE 7.3 and it worked for about three weeks now with SuSE 8.0 as well. What could cause such a problem? Any hints? Peter
Peter Gloor wrote:
After a reboot I can no longer get any network connection over the LAN from/to a SuSE Linux server (SuSE Linux 8.0 Professional).
The server has two NIC's. One to the internet (eth0) the other two the internal network (eth1). Only the internal network is affected.
While I still can ping between the gateway and the server I cannot ping between any other PC and the server using the internal network.
Using YAST2 I made some changes in the configuration, but I'm not aware of having changed anything specific to the network or security configuration (actually I added another partition and made changes to the time configuration; that's all I remember).
The gateway is a Windows NT server. All internal computers are configured to use this same gateway. Only the SuSE Linux server is affected by the problem. The configuration worked for months with SuSE 7.3 and it worked for about three weeks now with SuSE 8.0 as well.
What could cause such a problem? Any hints?
Let me see if I understand this: You changed some unrelated settings on your Linux Server (SuSE 8.0), and now the following has happened: gateway and server can still reach each other other computers and server cannot reach each other other computers and gateway can(not?) reach each other? Some questions: Do you use DHCP on your network? Can the other computers and the gateway reach each other? Which addresses/netmasks do you use on your network? Regards, Pieter Hulshoff
Pieter Hulshoff wrote:
After a reboot I can no longer get any network connection over the LAN from/to a SuSE Linux server (SuSE Linux 8.0 Professional). [...]
Let me see if I understand this: You changed some unrelated settings on your Linux Server (SuSE 8.0), and now the following has happened: gateway and server can still reach each other other computers and server cannot reach each other
Yes
other computers and gateway can(not?) reach each other?
Yes, other computers and gateway can reach each other!!
Some questions: Do you use DHCP on your network?
No, no DHCP at all.
Can the other computers and the gateway reach each other?
Again, other computers and gateway can reach each other!!
Which addresses/netmasks do you use on your network?
Destination Gateway Genmask Iface 192.168.11.0 192.168.11.1 255.255.255.0 eth1 212.xx.yyy.192 0.0.0.0 255.255.255.240 eth0 0.0.0.0 212.xx.yyy.193 0.0.0.0 eth0 Btw, if I change the gateway to 192.168.11.70 which is an ISDN router in the network it works. However, it worked before with the above configuration I dont want to (ab)use the ISDN router. Regards, Peter Gloor
No, no DHCP at all.
Ok, that rules out some possibilities. :)
Destination Gateway Genmask Iface 192.168.11.0 192.168.11.1 255.255.255.0 eth1 212.xx.yyy.192 0.0.0.0 255.255.255.240 eth0 0.0.0.0 212.xx.yyy.193 0.0.0.0 eth0
Btw, if I change the gateway to 192.168.11.70 which is an ISDN router in the network it works. However, it worked before with the above configuration I dont want to (ab)use the ISDN router.
So your gateway is 192.168.11.1 on one interface, the server is 192.168.11.? on that same network, the ISDN router is 192.168.11.70 on that network, and then there are some computers with 192.168.11.? on that network, all with the mask on 255.255.255.0? Do you only have to change the gateway on the server to the ISDN router for the other computers to see this server, or do you have to change it on all computers in the network? My apologies for all the questions, but I'm trying to get a view of how your network is setup. This problem is slightly more complicated than I had hoped at first. :) Regards, Pieter Hulshoff
Pieter Hulshoff wrote on November 02, 2002 8:34 AM
Destination Gateway Genmask Iface 192.168.11.0 192.168.11.1 255.255.255.0 eth1 212.xx.yyy.192 0.0.0.0 255.255.255.240 eth0 0.0.0.0 212.xx.yyy.193 0.0.0.0 eth0
Btw, if I change the gateway to 192.168.11.70 which is an ISDN router in the network it works. However, it worked before with the above configuration I dont want to (ab)use the ISDN router.
So your gateway is 192.168.11.1 on one interface, the server is 192.168.11.? on that same network, the ISDN router is 192.168.11.70 on that network, and then there are some computers with 192.168.11.? on that network, all with the mask on 255.255.255.0?
You got it. The Linux Servers IP address is 192.168.11.201 and the other computers ip addresses are something between 192.168.11.11 and 192.168.11.131 on that network. All have a mask on 255.255.255.0. As an example, this is what ipconfig on my PC reports: C:\WINDOWS>ipconfig Windows IP-Konfiguration 0 Ethernet Adapter : IP-Adresse. . . . . . . . . : 192.168.11.11 Subnetmask . . . . . . . . : 255.255.255.0 Standard-Gateway . . . . . . : 192.168.11.1 C:\WINDOWS>
Do you only have to change the gateway on the server to the ISDN router for the other computers to see this server, or do you have to change it on all computers in the network?
I only need to change the gateway on the Linux Server.
My apologies for all the questions, but I'm trying to get a view of how your network is setup. This problem is slightly more complicated than I had hoped at first. :)
No problem. In addition, on the same network, there is a MS Proxy server. The goal is to replace this proxy with a Linux (squid) proxy server. There might be one other thing you need to know. Physically the network is divided into two segments with two hubs. One hub (not sure, it might be a switch) serves all PC's and servers with 100 Mbit interfaces. The other one is a hub (for sure) which serves some older PC's and servers with 10 Mbit interfaces. There is also a coax attached to it which still serves 2 or 3 servers. There is a link between the two hubs. I'm telling this because first I used a 100 Mbit NIC, but I connected this with the 10 Mbit hub. This is similar to the gateway configuration which uses the same 100 Mbit NIC, but is attached (as the only exception) to the 10 Mbit hub (due to negotiation it automatically swites down to 10 Mbit). All Other PC and server have either 100 Mbit NICs attached to the other hub/switch or have 10 Mbit NICs attached to the same hub. I tried to change the NIC's, but the problem still exists. I expect the problem to be somewhere in the Linux config, but I have no idea where to look at. I cannot imagine an entry in the config that could cause this problem, like a kind of entry for "Don't use/use old routing protocol". The logs don't show any error or deny messages. Ping and traceroute indicate that the other NETWORK cannot be reached. I was a little bit surprised to find a completely new network configuration introduced with SuSE Linux 8.0. I will go thru the documentation to get familiar with it this weekend. Peter
Peter Gloor wrote on Friday, November 01, 2002 9:46 PM
After a reboot I can no longer get any network connection over the LAN from/to a SuSE Linux server (SuSE Linux 8.0 Professional).
The server has two NIC's. One to the internet (eth0) the other two the internal network (eth1). Only the internal network is affected.
While I still can ping between the gateway and the server I cannot ping between any other PC and the server using the internal network.
Using YAST2 I made some changes in the configuration, but I'm not aware of having changed anything specific to the network or security configuration (actually I added another partition and made changes to the time configuration; that's all I remember).
The gateway is a Windows NT server. All internal computers are configured to use this same gateway. Only the SuSE Linux server is affected by the problem. The configuration worked for months with SuSE 7.3 and it worked for about three weeks now with SuSE 8.0 as well.
What could cause such a problem? Any hints?
Peter
I just found a solution to my problem so I can give the answer myself. Pointing the gateway address to the Linux Server itself solved the problem. The IP address of the gateway (a Windows NT server) on the internal network is 192.168.11.1. The Linx servers internal network IP address is 192.168.11.201. My old configuration was: Destination Gateway Genmask Iface 212.xx.yyy.192 0.0.0.0 255.255.255.240 eth0 192.168.11.0 192.168.11.1 255.255.255.0 eth1 0.0.0.0 212.xx.yyy.193 0.0.0.0 eth0 My new configuration is (this solved the porblem): Destination Gateway Genmask Iface 212.xx.yyy.192 0.0.0.0 255.255.255.240 eth0 192.168.11.0 192.168.11.201 255.255.255.0 eth1 0.0.0.0 212.xx.yyy.193 0.0.0.0 eth0 Note: to protect our network from hackers some real numbers have been replaced by xx.yyy in the example above. Thanks for all the responses I've got. Peter
participants (2)
-
Peter Gloor -
Pieter Hulshoff