Dual Gateways

[scruge]

As anyone had any luck with operating dual WAN gateways on a small scale LAN?

I've got both DSL and Cable at home and I've been trying to get my 2 Linksys befsx41 routers to allow me to run 2 different gateways. I've got one router setup with the following IP 192.168.1.1, DHCP enabled and 2 PCs connected and their TCP/IP gateways set for 192.168.1.1.
The other router is configured as IP 192.168.1.128 and DHCP is disabled and there are 3 PCs connected to it with their TCP/IP gateways set for 192.168.1.128.

Router 1.1 is connected to the Cable modem via its WAN port and router 1.128 is connected to a DSL modem via its WAN port. The two router are connected together via the Uplink port of one router to port 2 of the other router. (linksys TS recommended port 2)

The problem..... Everything works great.. EXCEPT the fact that the 3 PCs connected to router 1.128 always use router 1.1 as the gateway dispite the fact their default TCP/IP gateway is configured as 1.128.


FYI Its seems the problem is with the DHCP services. If I enable DHCP in router 1.128 and disable DHCP in router 1.1 then all PCs start using router 1.128 as their gateway.

Does anyone have any suggestions?

[Greenstead]

Thats ineresting. I never tried this myself but I would have expected it to work the way you have configured it.

How do know for sure they are using the wrong router (I guess by watching the WAN leds flash).

What if you try setting one router LAN address to a different subnet (say 192.168.2.1), disable DHCP service on it, and force the NIC gateways to that.
(I'm guessing).

[scruge]

I can tell which gateway is being used by checking the Public IP with Whatismyip.com.

I was able to get everything working after trashing the junk Linksys routers and replacing them with a pair of $18 Airlink+ routers. Turns out the DHCP services in the linksys routers are crap.
Now my system works fantastic and hasn't been down a day for 8 months. Plus the Airlink+ routers port forwarding has 6x the capacity of the linksys and their tech support is 100x better than linksys.

[cszeto]

I just purchased an Airlink+ wireless PC Card, it seems to be pretty solid. Good to know that their routers have more flexibility in the areas that you identified.

[JackMDS]

The computers on the second Router has to be on another Subnet.

I.e. if the first Network is 192.168.1.x the second has to be 192.168.2.x

However you would have two separate Networks.

The Network behind the second Router would be able to access the First Network by using IP number.

But the Network on the First Router will not be able to access the Second Network since the Router's NAT will block it the way it Blocks the Internet.

You can configure a remote program like VNC to access the second Network through open ports.

Look at Note2 of the following page.

Link to: Ultr@VNC - Installation, and Settings.

[cszeto]

JackMDS, not sure what your posting has to do with setting up multiple gateways within a network or the Airlink+ products???

[scruge]

Originally posted by JackMDS
The computers on the second Router has to be on another Subnet.

I.e. if the first Network is 192.168.1.x the second has to be 192.168.2.x

However you would have two separate Networks.

The Network behind the second Router would be able to access the First Network by using IP number.

But the Network on the First Router will not be able to access the Second Network since the Router's NAT will block it the way it Blocks the Internet.

You can configure a remote program like VNC to access the second Network through open ports.

Look at Note2 of the following page.

Link to: Ultr@VNC - Installation, and Settings.

Interesting, it sounds as if you are saying NAT acts upon LAN traffic. I was under the impression NAT only acted upon traffic through its gateway.
Whatever the case both my gateways work fantastic on the same subnet.
If I want to change gateways for any pc all I do is change the default gateway on that pc and it instantly switches to that broadband service (gateway router). If one service drops then the PCs seek out the alternate if they've been configured to do so. The key here is to also configure DNS servers from both broadband services in the DNS settings for the PC. This will prevent your PC from not having a DNS listing for the alternate gateway when it switches.

[cszeto]

What he is trying to say is that when two NAT networks are stacked in series, the first network will only see the one "public" IP of the second NAT router and not the second network behind it.

He assumed that you had two NAT networks in series, when you are describing an arrangement where two NAT routers are in a parallel configuration to provide dual gateway access to the single overall network.

[scruge]

Originally posted by cszeto
What he is trying to say is that when two NAT networks are stacked in series, the first network will only see the one "public" IP of the second NAT router and not the second network behind it.

It assumed that you had two NAT networks in series, when you are describing an arrangement where two NAT routers are in a parallel configuration to provide dual gateway access to the single overall network.

oh, I understand now. These routers are in parrallel. I actually modified the configuration slightly since my first post. But the results are still the same. I have a 16 port switch that both routers are plugged into now. Where as before I had the routers daisy chained via their LAN ports before being plugged into the switch.

Sidenote: Now that both gateways have been up and running so well for the past 8 months I'm now interested in a means of combining their speed. As I recall they used to have software that allowed you to use 2 dialup modems to combine their speed. I need something similar to combined the 2 gateways. I'm sure I'd probably need another NIC to access the other gateway. But software is still needed to combined their speed.

[cszeto]

That will require a dedicated two port router. The software that you are referring to only ran on a single machine that has two modems installed, effectively making it a single two port router via modems versus NICs.

The configurations within this thread are beyond the typical basic SOHO networking discussions that takes place around here. There may not be any other similar configurations to compare with around this forum.

[scruge]

I didn't mean to steer the topic clear of its original subject, but it did occur to me that perhaps a single server capable of combining the speed of the 2 gateways may derive some enhancement to its upload speed.

Thanks for all the help, so far the Airlink+ routers are tops in my opinion for the $18 price tag. Their only short coming is their inablility to work with an IP updater, which can be resolved by other means.

[cszeto]

The topic was already beyond the typical SOHO networking discussions around here as most folks do not have access to two different high speed ISPs. Good information on the Airlink+ routers though...

[lukas]

Well now it is an interesting idea, i would very much like to figure this out also, i have a dsl(2MBit) connection and a Radio link(4MBit) and harnesing both for the speed is a good idea, the only thing is how can it work so that both register as one link to whatever service or host you are uploading and downloading to? If both are from seperate service providers, as mine are and it sounds like yours are, you will have to seperate ip's on the WAN side, making a request with one and trying to utilise the other also to increase the speed wont work as the service your acting on will see 2 different ip's and couldnt associate them as one, and in reverse, if you are hosting a service, someone makes a request on one ip, and the second one tries to send a responce, the users NAT or the open request wont recognise the legitemacy of the returned packets and drop them or wont be able to recognise the relationship the received packets have in relation to the sent request.
:S
tough problem.
Maybe this conversation is better served in a thread to do with FailOver connection Techniques?

[scruge]

I think the concept of combining broadband services has some merit and isn't far from someone coming up with a solution.
I've got several neighbors including myself that enjoy playing around with networks. We bought 6 wireless network bridges and have been bridging our networks and ISPs together.
We've had the Lan running pretty well now for 5 months and have a central server we keep our share files on.
We've often thought about combining our internet services to get an ultra fast connection for a single server. Rates in our area for broadband are DSL 256/1280 = $27/ mo 512/1280= $80/mo Cable 384/2560- $55/mo.

If we could combine 2 dsl lines we could get 512/2560 for $54/mo.

I think the key to combining is within the tcp/ip packet.
I've got a nephew who has his degree in computer Science and just finished all the cisco certs including security whom I hope will help us work a solution.

[JackMDS]

It does not matter what you do, in order to combine two broadband services to one you need Sync. at the source, otherwise you get two independent signals that do not know how to relate one to the other. There are few ISPs that provide this service (i.e. they will feed you with two lines in Sync.) but naturally it is very expensive.

If you buy your own two connections to the Internet Backbone you can use special Server software to create double "Speed" (the software goes for Thousands $$$).

There are inexpensive two WAN Routers but they do not combine the Bandwidth. They are set as Fallback or to use the fastest available but would not combine.

P.S. This topic comes up rather often by “Need for Speed Guys”. Unfortunately Wishful thinking does not create Technical Reality.