Dual Network Issue

jc0r

jc0r

jc0r

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1 Apr 2017
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20
Hi

I've got an issue with a machine been connected to 2 networks at the same time.

I have one network that I connect to with a wire that provides Internet, then my wireless adapter connects to a separate LAN that does not have Internet access but other LAN users I need to communicate with.

The ip address' are set to a different range so as to not conflict.

Initially all works well but after what would appear a random time, I lose access on my LAN network. I remain connected with an ip address to the network, but I cannot ping any other computers on that network and they can't ping me. I set the ip lease time to 24 hours on both networks incase that was doing anything but no joy. I also tried reserving IP address on both adapters, nothing. I looked into Metric index but can't see how that would help. I don't want to prioritise o e network over the other, I want them both to work at the same time.

Anyone got any ideas please?
 
Try increasing the DHCP lease time to a week or more. Or set yourself a static IP address for the LAN.

That said, are you sure it isn't the cable?
 
Thanks for the reply. I forgot to mention, when I lose access on the wireless lan, I can still ping the router just no other machine on that network and they can no longer ping me. The wired network that has Internet works fine.

Ive tried increasing lease time which doesn't help. I've set mine machine to have a static, that doesn't help either.
 
Sorry, I thought you were losing access to the wired LAN.

Have you tried checking for other wireless networks on the same wifi channel? Have you tried changing the channel of your wireless LAN?
 
Yeah there are no other networks in range. Like I say, I can still ping the wireless router, just not any of the other machines on the same network. It feels like a routing issue within the pc but I can't figure out what. I don't want to play with the metric as I don't want one network over another. I want access to both
 
Metric is irrelevant, it's used to set the "cost" of two available routes to prioritise.

Both networks need a different subnet and correct subnet mask. EG:
192.168.0.0/255.255.255.0
192.168.1.0/255.255.255.0

Does the wireless access point have wired link to the Internet router? Having multiple DHCP servers can cause issues as there is little way to determine which answers.

It actually just sounds like the Wireless network is broken and nothing to do with the dual networks.

Checking the route with the "route" command in a dos prompt would allow you to verify the route to each network is still via it's correct adapter.
 
If you can ping the router but not other clients it's not a metric issue but a routing issue. Have you tried adding a static route? You'll need to use the ROUTE ADD command.
 
There is no link between both networks. And as you say, one network range is 0.1, the other 1.1.

I will look into the route add cmd. Not something I've used before. Just seems strange it works on initial connection, then drops later. Many thanks
 
A route is only needed to get from one subnet to the other. The "device subnet" does not need a route as it's already on that subnet.

So if you wanted to access hosts on the wired lan from the wireless lan you would need a route to .. well... route the traffic via the gateway between them.

If you take the wired network out of the equation by unplugging it or admin'ing down the nic, can you reproduce the problem with the wireless still? I still think this is just a wireless network issue and the two lans is irelevant.

Is there any particular reason you want two subnets? You could just plug the wifi access point into the wired network and share the same subnet between all the devices. You will need to disable one of the DHCP servers or set one of them to relay to the other, but asides that it works fine.
 
jc0r said:
And as you say, one network range is 0.1, the other 1.1.
Click to expand...

That way lies madness. It's very easy to get confused when the IP address ranges are similar. I recommend having the networks on visibly different IP address ranges, e.g. 192.168.x.x and 172.16.x.x. It made sorting out problems so much simpler.
 
Quartz said:
That way lies madness. It's very easy to get confused when the IP address ranges are similar. I recommend having the networks on visibly different IP address ranges, e.g. 192.168.x.x and 172.16.x.x. It made sorting out problems so much simpler.
Click to expand...

LOL. I hear you. You should try having to divide 127.0.0.0 into a few thousand different subnets to test network management software. Now that gets to be a head melt and you need a calculator to work out which net is which.
 
An update after this setup was used yesterday. I rebuilt my machine that connects to both networks to get a fresh start. My setup worked flawlessly for 3 hours until I lost access to the machines on wireless lan. When this occurred, I was unable to ping the wireless access point however Windows reported I was connected to the network. The wired network was still functioning perfectly which gives me my Internet access. I disabled/enabled the wireless adapter which corrected the problem. I'm starting to think it may be a driver issue? I've got a stack of different wireless adapters so do you think it's worth swapping it out?
 
Try a different adapter, it sounds like it could be the adapter itself playing up. Maybe even a PCIe/USB ethernet adapter instead?
 
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