On Tue, Sep 4, 2012 at 4:00 PM, James B. Byrne byrnejb@harte-lyne.ca wrote:
That should happen directly without C's involvement if the netmask is 255.255.0.0 on A and B's eth1 interfaces.
It is not. The netmask on those interfaces is 255.255.255.0.
Netmasks apply to (and describe) connected subnets, not individual interfaces. Linux will sort-of sometimes work with mismatched subnet masks but some things won't see arp broadcasts with the wrong broadcast address (which again is for the whole subnet).
Instead it goes to Eth0 on C where it dies as one would expect.
Why does C have both internet and LAN addresses on the same interfaces?
I am experimenting to see if this arrangement is workable. I want to know if it is possible to have two separate 192.168.x subnets on the same network.
Some things might work sometimes. You can overlay separate subnets on the same wire, each with a correct subnet mask, and a designated router between them, but random things will happen with mixed netmasks.
Why? I do not have a purpose in mind. I am just checking out whether it can work or not.
You would probably be better off using VLANs than overlays in any case.
If it is impossible then then I will discover why that is so, which I think will be useful in itself.
The broadcast address for a subnet is tied to the bits in the subnet mask, and ethernets need arp broadcasts to work.
-- Les Mikesell lesmikesell@gmail.com