Very strange home networking problem

SuprSi

I've got a home built machine, connected to the Internet through IOLBB. I'm trying to share this connection with my flatmate but I'm getting strange results.

The first time we tried this it worked without a hitch, for about 10 minutes, then stopped working, even though we changed nothing on either machine. We're connecting directly from NIC to NIC using a cross-over cable, which is fine as we've tested it on another setup.

My machine detects that the cable is plugged in (or more to the point, it knows when it's been unplugged) and has a 169.254 address. My flatmates machine gets a 169.254 address when I plug the cable in, yet I can't ping it and he can't ping me. There's no activity on the connection, yet as I mentioned above when I unplug it Windows lets me know.

The funny part is that I can't even ping my own 169.254 address. I can ping localhost so I know the card is working, and I can connect to the Internet without any problems, but for some reason I can't contact my mates laptop.

I'm running Windows XP SP1, a 3Com network card, and I've got Symantec Personal Firewall installed - I've added my flatmate's machine into the trusted zone too.

Any help will be greatly appreciated.

Cheers!

joePC

Once you have ICS set up on the machine connected to the internet and allow it to accept connections from other computers,

Set the TCP/IP setting on both nics* to obtain an IP Automatic.....Shut down one machine and restart the other when this one is fully booted, start the other machine.

You will have connection between both comps.

Thanks joePC

ColmOT [MSFT]

If you are using ICS, you should be getting an IP address of 192.168.0.1 on the machine SHARING the connection, and another 192.168.0.x IP address on the machine sccessing the shared connection.

CHeck your networking settings again and verify this.

zoro

Originally posted by SuprSi
My machine detects that the cable is plugged in (or more to the point, it knows when it's been unplugged) and has a 169.254 address. My flatmates machine gets a 169.254 address when I plug the cable in, yet I can't ping it and he can't ping me.

At first glance I'd assume that you need to add an extra subnet to that ..

ie: 169.254.0.* instead of just 169.254.*.*

if you're on 169.254.1.1 and your friend is on 169.254.2.2 you wont be able to ping each other as you're both on different subnets (you're on 1, he's on 2)

as suggested, try manually setting the ip's to 192.168.0.1 (you) and 192.168.0.2 (your friend) and as you're both on the same subnet (192.168.0.*) it should work without a hitch after you setup the default gateway on your friend's machine to your own ip (as well as dns server)


Zoro

Emboss

Originally posted by zoro
At first glance I'd assume that you need to add an extra subnet to that ..

ie: 169.254.0.* instead of just 169.254.*.*

if you're on 169.254.1.1 and your friend is on 169.254.2.2 you wont be able to ping each other as you're both on different subnets (you're on 1, he's on 2)

as suggested, try manually setting the ip's to 192.168.0.1 (you) and 192.168.0.2 (your friend) and as you're both on the same subnet (192.168.0.*) it should work without a hitch after you setup the default gateway on your friend's machine to your own ip (as well as dns server)


Zoro

Lads 169.254.'s are assigned by windows when the nic is setup for DHCP and can't hit the DHCP server.......

169 is a reserved scope....

as mentioned all ready use 192.* or 10.* statically or setup DHCP correctly on the machine running ICS

zoro

Originally posted by Emboss
Lads 169.254.'s are assigned by windows when the nic is setup for DHCP and can't hit the DHCP server.......

What I meant was just that he wouldn't be able to access a machine on a different subnet - it doesnt make a difference what ip addresses you choose, be they 192.168..., 168.254... 10.... anything

I've had a similar problem before, and moving the machines onto the same branch of the subnet worked fine for me (that or bridging the connection)

Zoro

Emboss

Originally posted by zoro
What I meant was just that he wouldn't be able to access a machine on a different subnet - it doesnt make a difference what ip addresses you choose, be they 192.168..., 168.254... 10.... anything

I've had a similar problem before, and moving the machines onto the same branch of the subnet worked fine for me (that or bridging the connection)

Zoro

ugh,

I'm not missing your point

THE 169 IS ASSIGNED BY THE OS ITSELF....WHEN THERE IS AN ISSUE

i.e. A PROBLEM

the problem here being they are setup for DHCP with NO working DHCP server on the network....

assigning STATIC IP'S is a work around not a fix to the problem.


"sir we have 100,000 machines getting 169's seems to be an issue with

DHCP" "that's ok kid walk around to everyone of them and assign them static" "but sir that would take months" "DO IT!"