Networking problem

[mark88]

I have a wifi network with a mix of macs and PCs. All machines have a wifi intrerface with an IP of 192.168.1.x

I'd like to connect 2 machines together using a cross-cover cable so I can benefit from gigabit speeds between those 2 machines. I have done so and the ethernet interface on each machine gets an IP of 169.254.xxx.xx

The only problem I have is that in Finder when I click Network in the sidebar, the PC that has 2 IPs(1 for its wifi and 1 for its ethernet) keeps vanishing from the alias list of servers. It will be there when I boot, I can connect to it fine but afterwards it will disappear, even though I can still access it via command+k.

Any ideas as to why this is happening? None of the other machines do this and it only started happening when I starting using the cross-over cable along with wifi.

 

[Queso]

Is the PC's power saving allowed to put the interface to sleep?

 

[tyr2]

. I have done so and the ethernet interface on each machine gets an IP of 169.254.xxx.xx

You should assign a specific IP address to each machine. 169.254.x.x addresses are assigned when a machine has been unable to find a DHCP server to get an address. These addresses may change when you reboot your machine.

You could use 192.168.2.x with a netmask of 255.255.255.0 and a broadcast of 192.168.2.255 for the machines on the gigabit network.

 

[mark88]

Is the PC's power saving allowed to put the interface to sleep?

Do you know where abouts I might be able to find that out?

 

[mark88]

You should assign a specific IP address to each machine. 169.254.x.x addresses are assigned when a machine has been unable to find a DHCP server to get an address. These addresses may change when you reboot your machine.

You could use 192.168.2.x with a netmask of 255.255.255.0 and a broadcast of 192.168.2.255 for the machines on the gigabit network.

hi, what do you mean by 'broadcast'?

At the moment all the machines on the wifi network have a fixed IP of 192.168.1.x,

Can I ask why do you say to set them to 192.168.2.x? Is this so it doesn't conflict with 192.168.1.x?

I do recall trying yesterday to set the ethernet interface IP's to 192.168.1.x as well but this just didn't work at all.

 

[tyr2]

> hi, what do you mean by 'broadcast'?

It's the address that machines use to 'broadcast' messages to other machines on the same network. It seems you don't need to set this in OS X (it'll figure it out itself) I can't remember about Windows ottomh. If it doesn't ask don't worry about it

> Can I ask why do you say to set them to 192.168.2.x? Is this so it doesn't conflict with 192.168.1.x?

Yes. If you want gigabit connectivity between these two machines they'll be on a different physical network so you should assign addresses that reflect this. Otherwise you'll get into problems with routing the traffic correctly.

> I do recall trying yesterday to set the ethernet interface IP's to 192.168.1.x as well but this just didn't work at all.

No it won't. When you try to connect to (say) 192.168.1.10 your machine will probably send the request over the wireless network, it'll never get to the gigabit interface on the other machine. Set them to something in a different range.

 

[mark88]

> hi, what do you mean by 'broadcast'?

It's the address that machines use to 'broadcast' messages to other machines on the same network. It seems you don't need to set this in OS X (it'll figure it out itself) I can't remember about Windows ottomh. If it doesn't ask don't worry about it

> Can I ask why do you say to set them to 192.168.2.x? Is this so it doesn't conflict with 192.168.1.x?

Yes. If you want gigabit connectivity between these two machines they'll be on a different physical network so you should assign addresses that reflect this. Otherwise you'll get into problems with routing the traffic correctly.

> I do recall trying yesterday to set the ethernet interface IP's to 192.168.1.x as well but this just didn't work at all.

No it won't. When you try to connect to (say) 192.168.1.10 your machine will probably send the request over the wireless network, it'll never get to the gigabit interface on the other machine. Set them to something in a different range.

ok, here's what I have just tried.

PC:
Wifi IP = 192.168.1.2
Ethernet IP = 192.168.2.2
Both have router 192.168.1.1, subnet mask of 255.255.255.0

Mac:
Wifi IP = 192.168.1.10
Ethernet IP = 192.168.2.10
Both have router 192.168.1.1, subnet mask of 255.255.255.0

Once applied I could connect between the two machines perfectly, but the connection to the internet and other machines on the wifi network just stopped. Am I missing something?

thanks for your help

 

[mark88]

I also get this warning

 

[tyr2]

Leave the 'router' (or 'gateway') entry blank, it'll get confused otherwise.

You should only have a router specified on your wireless connection as that the interface you're using to get out to the internet.

edit: Leave it blank on the gigabit interface, and set it to 192.168.1.1 on the wireless connection, if that wasn't clear.

 

[mark88]

Thanks, that's working for now. I'll have to see if the windows machine alias remains in Network this time.

I'm in the same city as you well I just realized. Cheers

 

[tyr2]

> Thanks, that's working for now. I'll have to see if the windows machine alias remains in Network this time.

Excellent, glad to hear it's working

> I'm in the same city as you well I just realized.

Cool. Here's hoping the sunny days come back soon.