topic diff class c network and routes ... in Operating System - Linux

diff class c network and routes ...

K.C. Chan — Sat, 08 Jan 2005 10:51:50 GMT

All,
let say the router/firewall is 192.168.10.1/24 (router to the outside world) and I have two differenct class c network . One is on 192.168.10/24 and the other is on 192.168.20/24. Do I need a router to communicate between the two network? In a nutshell do I need a router to communicate btw two class c network.

Let say, the answ. is No, I do not need a router to communicate btw the two network. Then for 192.168.20/24, what is the route for this, can I used 192.168.10.1/24 as the default route? thanks.

Re: diff class c network and routes ...

Vitaly Karasik_1 — Sat, 08 Jan 2005 15:01:52 GMT

AFAIK, you need router; in fact you may just add one more NIC to your existing router/firewall.

Re: diff class c network and routes ...

Gerhard Roets — Sun, 09 Jan 2005 09:49:54 GMT

Yes you would need a router.

But since you have a router already inplace you might be able to use some creative interfacing assignments to achaive your goal. i.e. subinterfaces or vlans depending on the technology at your disposal.

The other way might be to investigate some other RFC1918 compliant addressing schemes

3. Private Address Space

The Internet Assigned Numbers Authority (IANA) has reserved the
following three blocks of the IP address space for private internets:

10.0.0.0 - 10.255.255.255 (10/8 prefix) - CLASS A
172.16.0.0 - 172.31.255.255 (172.16/12 prefix) - CLASS B
192.168.0.0 - 192.168.255.255 (192.168/16 prefix) - CLASS C

I would go for the 172.16.0.0 network. Just an option though.

There is also a good nummber of opensource ethernet routers available if re-orgnising your ip's is to daunting a task :)

HTH
Gerhard

Re: diff class c network and routes ...

Gerhard Roets — Sun, 09 Jan 2005 09:52:01 GMT

Hehehe

Just noticed this in under linux. Routed + 2 network cards in an always up machine would definitely be a very cheap solution :)

Gerhard

Re: diff class c network and routes ...

Marcus Augustus_1 — Fri, 14 Jan 2005 06:34:16 GMT

The really simple solution is to just use a different subnetmask so the two networks wil become one ... ofcourse this rather depends on how many nodes you got and whether or not you are using DHCP.

If its just a few hosts, try setting all subnetmasks to 255.255.224.0. That way you won't need an extra router.

Good luck!

Re: diff class c network and routes ...

K.C. Chan — Fri, 14 Jan 2005 11:34:57 GMT

OK,
Would a default route to 192.168.10.1/24 if I set this on server with 192.168.20.0/24? Was told by a fellow sysadmin, this works.

I am at work now, so I will try it when I get home. Mean while, any thoughts?