Hosts in LAN cannot see each other

Hi everyone, this is my first visit to the forum so my questions may already have been answered, but here goes. I have set up a LAN with a 5-port ethernet hub and uplink. Port 1 is connected with a straight-through cable to PC1 running XP Home; port 2 is connected with a straight-through cable to PC2 running Linux Mandrake 9.2 (dualled booted with Windows98); port 3 is connected with a cross-over to a DSL router. All the right connection LEDs are on, on hub and router.

Each PC connects to the Internet via LAN and each is able to manage the router adapter at 192.168.1.1, however they cannot see each other through GUI application interfaces or using PING or other tools. DHCP server is enabled with automatic IP allocation.

1) Should the cross-over be replaced with a straight cable?
2) Is it purely a software setup issue?

From your writeup, it is clear that both machines are correctly receiving IP addresses via DHCP as they are able to access the router as well as the internet. Therefore the crossover cable to the router is not an issue. The router probably have automatic crossover detection built-in anyway.

Your problem is definitely to do with the OSes on the PCs you're running. XP with SP2 will not respond to pings because of the built-in firewall. Also depending on your configuration of Mandrake, this may also be the case. Try disabling your XP firewall and then ping from the Mandrake PC. Or you could boot up in Win98 which has not firewall and try to ping from the XP machine.

Yeah most of the times its the default windows firewall or a alternate software firewall which prevents access between host's.
Btw have you shared any resources? Files/folders?

Thanks DaLight & digen,
I switched off both firewalls and rebooted and voila! the hosts can see each other. I now need to do a bit of tweaking to share my XP Printer. I can use it from Linux but nothing happens (must be to do with CUPS or Samba or something (I am a novice at all this, Linux and Networking)). XP Files are now shareable, again I am finding out about permissions and Samba etc. but in XP I don't have permission to view my Workgroups! I'll try a few more more options, at least my original questions have been answerd.

Now I am vulnerable because I have no Firewalls. Do I have to switch them on to use the internet and switch them off to use resource and file shares?

Thanks Again.

Your router should have a built in firewall, set that up as your default firewall, if not, either get a new router, or use a machine to act as a firewall/server.

It should be like this:


MODEM (INTERNET) > ROUTER (LAN) > FIREWALL (PC/ROUTER) - DESKTOP 1 - DESKTOP 2 - DESKTOP 3 - PRINTER - ETC


This way, all the machines are protected. You do not need to have any desktops with firewalls. All the connections flowing out of the router should be filtered.

Ofcourse, protected until you setup a 2nd NIC on one of the machines that will expose your lan! But lets not let that happen.

Now I am vulnerable because I have no Firewalls. Do I have to switch them on to use the internet and switch them off to use resource and file shares?

Naa.Which software firewall you got there.You will have a option of adding a LAN connection as something "trustable network" which wouldnt block connections to your internal network.
ZA has such a option which lets you allow a network to be configured to the way you want it.