I seem to have broken my ICS

[Bursar 0]

I'm not sure exactly what's gone wrong, but here's the story, so maybe someone can help out.

 

I had a PC running WinXP with 2 network cards. One was hooked up to my cable modem, the other was connected to a switch into which another machine was connected. The cable modem was connected to a 3COM PCI card, and the LAN was run from the onboard NIC.

 

The cable modem NIC was set to DHCP, and the LAN NIC was as follows:

 

IP: 192.168.0.1

SN: 255.255.255.0

GW: <blank>

DNS: <blank>

 

The client machines was configured as follows:

 

IP: 192.168.0.2

SN: 255.255.255.0

GW: 192.168.0.1

DNS: 192.168.0.1

 

This all worked perfectly.

 

Over the past few days, I dismanted that PC and rebuilt it (new mobo, RAM, hard disk and so-on).

 

I reinstalled XP, installed all the patches and got the Internet up and working. I then came to look at the LAN, and I cannot get it working for the life of me.

 

The new motherboard in the 'server' machine has an onboard Realtek NIC, and it seems to be working OK. I have configured as above.

 

The client machine hasn't changed in anyway, but I can't get the PCs to talk to each other properly.

 

Pinging is very intermittent, and ICS just doesn't work at all. I don't think I've missed anything obvious, but if I have, I'd love to know what it is.

 

In the meantime, I'm going back to pulling my hair out.

 

Please save me before I'm completely bald....

[Bursar 0]

I've done some more tests, and here's what I have now...

 

PC1 (server) WinXP - all patches - 192.168.0.1

PC2 (client) Win2K - almost all patches - 192.168.0.2

PC3 (client) WinXP - no patches - 192.168.0.3

 

PC1 can now ping PC2 and PC3.

 

PC2 can ping PC3 but not PC1.

 

PC3 can ping PC2 but not PC1.

 

I've enabled logging on PC1, and here what I get. Hopefully the formatting hasn't gotten too mangled:

 

Code:

date time action protocol src-ip dst-ip src-port dst-port size tcpflags tcpsyn tcpack tcpwin icmptype icmpcode info2003-10-19 19:41:22 DROP UDP 192.168.0.1 239.255.255.250 1900 1900 436 - - - - - - -2003-10-19 19:41:22 DROP UDP 192.168.0.1 239.255.255.250 1900 1900 442 - - - - - - -2003-10-19 19:42:15 DROP UDP 192.168.0.2 192.168.0.1 1042 53 62 - - - - - - -2003-10-19 19:42:16 DROP UDP 192.168.0.2 192.168.0.1 1042 53 62 - - - - - - -2003-10-19 19:42:18 DROP UDP 192.168.0.2 192.168.0.1 1042 53 62 - - - - - - -2003-10-19 19:42:20 DROP UDP 192.168.0.2 192.168.0.1 1042 53 62 - - - - - - -2003-10-19 19:42:24 DROP UDP 192.168.0.2 192.168.0.1 1042 53 62 - - - - - - -2003-10-19 19:42:32 DROP UDP 192.168.0.2 192.168.0.1 1043 53 68 - - - - - - -2003-10-19 19:42:33 DROP UDP 192.168.0.2 192.168.0.1 1043 53 68 - - - - - - -2003-10-19 19:42:34 DROP UDP 192.168.0.2 192.168.0.1 1043 53 68 - - - - - - -

 

The first two entries are pings, the others are requests for a web page. So for some reason my machine is just dropping the incoming requests from my LAN. I'm a bit stumped about what to do...

[Bursar 0]

It's OK, I fixed it Realised I should have been setting up ICS on the broadband NIC rather than the LAN NIC. D'oh!