Network Nightmare... need some advice.

lelrod · 11-18-2002, 02:19 AM

I have a Linux server setup with Redhat 7.3. The system has 2 network cards. The network is a Class C Private Subnetted in half. the 192.168.1.0 sub is assigned to eth0 and the 192.168.1.128 subnet is assigned to eth1. I have 3 computers connected to a switch with the linux server running samba. All of the machines work fine except 1. System boots up works for a while (could be 5 mins or 1 weeks) then I loose internet connectivitiy. I am not using a proxied connection; I am using the caching name server on the linux machine but I completely loose connectivity with the server. I can ping the other machines and the router on the 192.168.1.0 subnet but I am not able to ping the server. I am also running VMware GSX server with a windows 2000 server on the linux server for remote access. I am able to ping that IP. But not the IP of the server with linux installed. I am ready to pull my hair out. I am not sure if this is maybe a bug with SAMBA or I have a NIC going bad or what.... Has anyone seen or heard about a problem like this? Any help or advice would be appreciated.

TIA
Louis

ICEBlur · 11-18-2002, 08:32 AM

Do you mean your subnet mask is 255.255.255.128? Unfortunately, that subnet mask only creates two subnets. As a general rule of thumb, you cannot normally use the first and last subnets. Since your subnet mask is 255.255.255.128, this only creates two subnets, which both are not useable.

I would recommend using this subnet mask: 255.255.255.192

This will make two useable subnets having 64 hosts per subnet.

Subnet 1 (Unuseable): 192.168.1.0 - 192.168.1.63
Subnet 2 (Usable) : 192.168.1.64 - 192.168.1.127
Subnet 3 (Usable) : 192.168.1.128 - 192.168.1.191
Subnet 4 (Unuseable): 192.168.1.192 - 192.168.1.255

I hope this helps you out!

stickman · 11-18-2002, 08:45 PM

Umm, I think that you (ICEBlur) mean that the first and last IP in each subnet should not be assigned to a machine. A 255.255.255.128 subnet is perfectly valid and very usable.

I'd be curious to know what IP addresses are assigned to eth0 and eth0 on the Linux system. You might also want to check the IP config (especially netmask) on the system that is not working.