How do I subnet 2 different ip sets into one network?

[BamaMike]

Here's the problem. I help administer a network with 2 seperate ip sets (e.g. 192.168.123.xxx and 192.168.124.xxx). Currently the computers on the different sets can't talk to each other without going through the router which is putting some strain on my network. How can i use subnetting to allow the to talk to each other without hitting the router

 

[GigaCluster]

I believe the point of subnetting is to contain traffic to certain subnetworks and to allow a router to control the communications between those subnetworks.
If you want to avoid routers in your network, why are you using subnets?

 

[BamaMike]

What i'm trying to do is cut down on the traffic to the router. I want the 123 and 124 to be able to talk to each other without having to hit the router. Is subnetting the way to go on this or is there a better way?

 

[GigaCluster]

So what else, besides the router, is separating the two networks?

If the setup is something like [NETWORK A] --- [ROUTER] --- [NETWORK B], then obviously it has to go through the router no matter what... how is your network topology set up?

 

[BamaMike]

I'm sorry, I said I was subnetting, i meant to say that i was trying to use a subnet mask.

 

[GigaCluster]

Hmm, I don't know if I am right or not, but IP addresses beginning with 192.168.123.x and 192.168.124.x are not in the private IP range. It doesn't matter for this particular exercise, but your network is not on the Internet, is it?

Anyway, if you want the two networks to talk to each other, just use the same subnet mask. An appropriate one for your situation would be 255.255.0.0, although I may be wrong since your IP addresses are weird.

In regard to going through your router: is there another path that packets can take? If only the router is standing between the two networks, then packets have no choice but to go through it.

 

[BamaMike]

those aren't the real ip addresses. They are just something i used as an example. The IP's we are using are not within the private range.

 

[GigaCluster]

So every system on your network has a public (Internet-accessible) IP address? In that case, you should use the subnet mask that your ISP gives you.
You are avoiding my question for the second time now... how do you intend to cut down on the traffic to your router? Is there an alternate path that packets can take to avoid going through the router?

 

[BamaMike]

Thanks, using a subnet mask of 255.255.0.0 fixes the problem. Is there any advantage to using a mask of 254 since it limits the possible subnet masks?

 

[BamaMike]

in response to your question, we have [desktop]-[switch]-[router]

 

[BamaMike]

 

[GigaCluster]

Originally posted by: BamaMike
Thanks, using a subnet mask of 255.255.0.0 fixes the problem. Is there any advantage to using a mask of 254 since it limits the possible subnet masks?

Using the subnet mask of 255.255.255.254 is not possible, actually, because it does not leave any room for hosts. Do you know much about subnets?
An IP address in binary consists of network bits, subnet bits if any, and host bits. In a subnet mask, network and subnet bits are represented with ones, and host bits with zeroes
You cannot change your network bits. You can only manipulate subnet and host bits. "254" would be 11111110 in binary -- that is seven bits for subnet and one bit for hosts. Since two host addresses .0 and .255 are not usable by any machine, that effectively leaves you with no hosts.

If you don't want subnets, just use a subnet mask with only your network bits (you can ask your network administrator about that) represented; everything else would be zeroes.

Without knowing your true IP addresses, that's the most I can tell you about that.

Now, about your network topology. If your switch stands in the way of workstations and router, the router should not be disturbed unless there are communications with the Internet. Subnetting definitely isn't going to help you reduce (or at all affect) the router's bandwidth requirements.