1 subnet 2 wans

[alimnios72]

Hi,

I have 2 routers, 2 wans and about 16 PC's, I want to know what is the most efficient solution if i need to route some computers into WAN1 and the others through WAN2. I've think about having 2 subnets and static routing to communicate between all PC's, but I read that some IT managers see more efficient to have just 1 subnet.
What do you recommend?

 

[jimbopalmer]

I reccomend a multi WAN router.

I use both RV042 and a sonicwall, both are fine.

I tried to remain child-like, all I acheived was childish.

 

[alimnios72]

In fact i have 2 Thomson TG585 routers, is there a way to achive what i'm expecting?

 

[jimbopalmer]

Sorry I thought you asked what I would recommend.

If you held a gun to my head and said "do it wrong and make it work'

I would make one router 192.168.1.1 and turn on DHCP from, 192.168.1.200 to 250.
I would make the other router 192.168.1.2 and disable DHCP.

Then I would Hard code 8 PCs with addresses 192.168.1.10 to 20 and mask 255.255.255.0 and gateway 192.168.1.2


I would refuse to support it, but it would work.

I tried to remain child-like, all I acheived was childish.

 

[alimnios72]

Thanks for your reply. I felt more comfortable with static routing between both routers, each subnet has it's own WAN access.

Thanks anyway

 

[muckermucker]

The thing is, none of that will work... even Jimbo's reply...
At least from what I read.

I am making some assumptions, these are that the two sites are in physically different locations and have to traverse the WAN or a router to get to each other. And that the router with IP 192.168.1.2 is at the remote site.

This means very simply that each site much have a unique subnet. If one site uses 192.168.1.x and so does the other then even hard coding the routing the way Jimbo said would not work because any traffic destined for the 192.168.1.x network would NEVER go across the WAN. This is because the remote network is seen as local/home/ it's own network. Traffic is ONLY EVER sent to a (default) gateway (to "route") if the destination IP address isn't a member of the local subnet. Because every IP destination will start with 192.168.1.x it sees these as local therefore they don't get sent to a gateway and never try to be routed.

Your scenario will fail every single time unless you give the two sites separate subnets. This is basic core of what routing is. It "routes" traffic between different subnets...

See the following article I wrote for the basics of IP addressing, subnets and gateways

http://think-like-a-computer.com/2011/03/09/the-differences-between-tcp-and-udp/

 

[muckermucker]

Errr where is the edit button for my post, cant you do it??
I posted the wrong link, here it is

http://think-like-a-computer.com/2011/03/04/the-basics-of-ip-addressing-subnet-masks-and-routing/

I forgot to say what I would recommend. That would be to create two separate subnets and just link then via a site-to-site VPN. This easily you best option. Routing is taken care of AS LONG AS THESE ROOUTERS ARE ALSO YOUR DEFAULT ROUTERS FOR INTERNET TRAFFIC. If they are different you need to do a bit more so let us know.

 

[alimnios72]

Thanks for your reply muckermucker, in fact both routers are in the same location and did solve this issue with static routing. I created three subnets, one common to both routers and I did the link through that subnet, now is working great.

BTW I found your article very interesting, keep it up!

 

[jimbopalmer]

Had you been at separate sites, the RV042 would still have worked, for the wrong reason, it is also a IPSec site to site VPN router, you would have needed two of them.

Correct me if I am wrong, but your solution has no failover right? If one ISP goes down, half the PCs are without internet?

I tried to remain child-like, all I acheived was childish.

 

[muckermucker]

Ahhh I see now what you both mean. I misread interupted your original post. I thought you were saying you had separate sites connectied via a WAN but they were on the same range. I see now that it is all the same network but you have two ways out onto the internet (gateways). In that case I take it back Jimbo was right first time ;-)

Alimnios I know this has nothing to do with this but if you wouldn't mind could you leave a comment on my blog pls? i would really appreciate it. The site is only 3 weeks old and it is nowhere to be seen yet on google hence the no comments. Trying to drive some traffic to it. No worries if you cant, thanks.

Take a look at my IT blog guides, knowledgebase and technical resources at

http://think-like-a-computer.com