ping host unreachable
 

I have 4 PCs.

Boxes #2, #4, and #5 are running linux. Box #1 is running NT.

Three boxes (#1, #2, #5) can ping each other.

Box #5 can ping #4, other two boxes #1 and #2 can not ping #4.

Box #4 can ping #5, but can ping other two boxes #1 and #2.

Why box #4 is reachable by #5 but unreachable by #1 or #2?

Any help is greatly appreciated.

Thanks.

Charles Yang

What's the IP address/subnet mask of each host and how are they physicly connected?

Box NIC IP Subnet

#1 192.168.1.102 255.255.255.0

#2 eth0 192.168.1.103 255.255.255.0

#4 eth0 192.168.1.101 255.255.255.0
#4 eth1 192.168.2.101 255.255.255.0

#5 eth0 192.168.1.100 255.255.255.0
#5 eth1 192.168.2.100 255.255.255.0

I used two hubs.

eth1 of both #4 and #5 are connected to hub1.

Other NICs are connected to hub2.