Lan network won't work!?

Question

Our master P.C connects directly to the modem and a separate lan cable comes out to a switch which we use for other p.c's on the network, this has been working for months but recently our ISP had to reset the I.P on the master and the other slaves no longer work? We weren't using DNS, used different I.P's and the same subnet and gateways, nothing works, can't even ping the other PC's now either. Help!

Answer 1

Check the IPs allocated to each PC... if they are windows, open a command prompt and use ipconfig.



Check that they all look like they belong (i.e. all of the slaves and the master's connection to the switch have IP addresses in the same subnet). Check that the slaves all use the master as gateway. Check that the master's routing table routes internet traffic to the modem and routes internal traffic back to the slaves.



If the IP addresses have got messed up, set them right.



Then check with ping... make sure you can ping each machine from the others. If you can't your switch has coincidentally failed... or if your PCs have changed IP addresses, check your switch config to make sure it's not configured with a VLAN or otherwise se so it ignores the 'new' IP addresses as not acceptable.



If you think the switch is snafu, try connecting one slave directly to the master with a crossover cable. Itf that fixes it, your switch is to blame.



Your master PC shouldn't care what the ISP's allocated IP address is. It should use DHCP on that port to get one automatically... unless you've got a set IP address. Not sure I understand why you are setting the 'slave' pc addresses rather than using DHCP from the master.



Can you 'surf' from the master still?

Answer 2

Two things. Either the PCs are no longer on the same subnet or the switch is busted.



Can one slave ping another. If they can then the network is OK.



If the slaved can ping eachother, but not the 'master' then check the subnets and default gateways on all of the clients.



I suppose it is possible that the cable between the master and the switch is bust - maybe try changing that too....

Answer 3

If someone's changed the IP address of your "master", and suddenly it cannot communicate with any other computer on the network, the most likely problem is that it is on a different subnet. It's probably not a gateway or hardware issue, as those did not change.

Check the IP address of the master computer (the LAN card, not the modem). It should be on the same subnet as the other computers. If not, fix it. If so, then check the default gateway settings on the other computers to make sure they are pointing to the master's IP address.

Answer 4

The onboard LAN is a under pressure out Ethernet port. If it would not say it comes with WiFi, you ought to the two get a USB WiFi adapter (that is going outdoors the computing device) or a PCI WiFi adapter (that is going indoors). They fee approximately $15.

Answer 5

I have question about your net config., you can write me via email add... :-)