"Network Unplugged" Madness

[ecorcor]

Hello Folks :wave:

I am new here and hoping for some help with this insanity. I have a 3 machine network and I just recently switched to Comcast from a dsl connection. Perhaps it just coincidence but when I switched I started getting "Network cable unplugged" balloons and losing internet connectivity. I am wondering if there is a virus that does this as I am having a hard time believing all my NICS, Cables and routers are all bad all of a sudden. I have tried different cables, switched NICS and have 2 Barricade routers, both SMC. The problem is intermittent and when the message ballon is flashing all my lights are green, seemingly I am connected but no access. I just reformatted a machine for a friend and plugged into the router to pass over some files and instantly got the Unplugged message. I am not a guru but have experience with these boxes but really I am at a loss to find out what's doing this. All machines are running XP and ran problem free untill aforementioned service switch. Also, when I log into the Barricade to see what numbers are there, my subnet mask is 255.255.252.0 while all my NICS have 255.255.255.0. Is this normal? I thought they should match and was wondering where the router was pulling it's numbers from? Any help with this will be appreciated. Thx for reading.

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[mikescorpio81]

So you router or whatever your PC's are using as their gateway has an active DHCP scope? Do you know the IP address of the router? Can you ping it from each PC? If not try the following:
On each PC, in the NIC properties under TCP\IP make sure they are all set to obtain IP address and DNS automatically. Then in a command prompt on each PC type ipconfig /release (followed by) ipconfig /renew
They should all get an IP address from the router (if properly configured) and you can check by doing an ipconfig /all afterwards on each PC.

Try this first and if you're still stuck we'll go from there.

Cheers

 

[Nodsu]

Are you sure this 255.255.252.0 netmask applies to your LAN and not the internet side of the router?

Are the routers identical? How about updating to the latest firmware?

Also, ethernet link speed autonegotiation is far from perfect. Try setting the link speed manually in the NIC properties to 100Mbit full duplex.

 

[DelJo63]

Also, when I log into the Barricade to see what numbers are there, my subnet mask is 255.255.252.0 while all my NICS have 255.255.255.0. Is this normal?

each system will be fine with the 255.0.

the routers having 252.0 allows them to pass extra traffic. no harm, no foul here.
this is a technique known as supernets, but let's not go into that until you get
a reliable connection. this is not a contributor to your problem.