Adding a Subnet

[Guntha]

I was hoping I could get some opinions on something I'm trying to get done. Recently I revamped our LAN at work using a fiber/gigabit backbone. Now our process LAN would like to utilize my existing LAN wire and backbone. The engineers would like to gain access to their PLC's and process PC's thru their regular PC's (on my network). Their IP scheme is diferent from mine and I know I would need a router to connect the two LANs. Would I be better off mulithoming an NT box or putting in a new router? What model router would be the best for my needs? I have an existing 2610 but it is serving basic router functions an internal IOS firewall and VPN services so it's pretty busy. There would be no more that 50 devices on the Process LAN, 100 on my LAN. If the engineers would want to access the Process LAN I have to change their default gateway to the new Router (or multihomed NT box), how would they be able to access the Internet now that their default Gateway is no lnger my normal router? I hope I made sense here. Thanks and I appreciate any and all suggeestions!!

Alex

 

[rburke]

Well, it I would say that a 2621 or another 2611 would work find connect the two LAN's... the only idfference between teh two is that the 2621 has 2 Fast Ethernet built-in ports and the 2611 has the two built-in Ethernet ports. Also, you could try a 2514, it has 2 built-in Ehternet ports, and hte benift would be the cost... it is alot cheaper than a 2611, or 2621. Plus it would be able to handle the amount of users you described.... The only problem is that you would need 3 ehternet ports to get out to the internet, one for hte engineers, one for the LAN and one to get to the 2611 that goes out to the net. Really the only other option, in terms of cisco routers, would be to try a 4000 series router, actually the 4500 or 4700 models. It is end of Sale already, but it is modular (3 slots) and has modules with 6 ethernet ports, 2 ethernet ports, or one Fast Ethernet port. Along with assorted other modules(token ring, serial, etc.) Plus it has the processor of a 3640 router, so it could easilh handle the workload and then some.... Plus they are pretty cheap, you can pick on up on Ebay with 12.x.x Enterprise IOS, for around $500. I have 2514's and a 4500, so if you want more info on those routers(the specs, not for sale) let me know.... Hope this helps....

burke

 

[Guntha]

Thanks for the reply!
In researching the 2514 I have found that it has only one 10 MB ethernet port and one port for console (going by the piuctures) is there an option that would add the second ethernet port? I have a switched 10/100 LAN but all my devices run at 100 MB full duplex. I would assume that the 2514 would become a bottle neck on my LAN. Would this be reason enought to go to the 4xxx series of router for the fast ethernet capabilities?. $500 is more along the lines I would like spend. Would the 4500 series router be to replace the 2610 I have in place and add the functionality I would need to connect the 2 LANS? Sorry for all the questions but I'm not an expert in these matters by any stretch. If I could keep my existing 2610 in place I would rather do that. There is a lot of shtuff on there that was kind of a bear to get working properly.
Thanks.

Alex

 

[rburke]

It sounds like you were looking at the 2501, it has the one fixed 10 Mbit ehternet interface, but the 2514 has 2 fixed 10 Mbit ethernet interfaces. And both of them have console, auxilary and 2 serial interfaces. The 4500 itself(IOS, memory, etc) is around $500, but the Fast Ethernet (100Mbit) module is around another $400-500 and you would need 2, since you would want to connect the two LAN's at 100Mbit. Probably from what you are saying, the 2621 would wuit you best. It has a 50 Mhz processor, like the 2610, but it has 2 10/100 interfaces built in. Unfortunetly, it is around $1400-1500 for one off of Ebay which is the cheapest place you'll find them. So the choice is to try to find a 4500 with 2 Fast Ethernet modules with a total price of around $1400-1500, look for a 2621 for around the same price, or deal with a bottleneck in the network but for ALOT cheaper. It really depends on how much traffic will be traveling through.
Eventhough the 2514 has 2 10Mbit Ethernet interfaces, those would be fine if there wasn't ALOT of traffic, but if it is going to have alot of traffic, then you should probably go with the 100Mbit routers.... Let us know a little more about hte type and amount of traffic that will be going between the LAN's and we can help you make a more informed decision... As you can see there are lots of options to fix the situation.... Let us know....

burke

 

[Guntha]

The traffic would not be a lot at all. 5-7 engineers on my LAN crossing to theirs, and the rest of the nodes on the other side would be PLC processors, drive packs and about 12 NT 4.0 W/S PC's. Only a few of these PC's would actually traverse the LAN's for data collection from the PLC's to the AS400. Should be a minimal amount of traffic, so the 2514 should probably suit me fine.
Would physical location of the router be a factor? I want to keep the router in the main building. You mentioned something about me needing 3 ports on my router for my Engineers to be able to acces the Process LAN and also be able to get pout to the internet. Could I solve this by using satatic addresses, using the new router as the default gateway, but providing the Engineers PC's with my ISP's DNS server addresses?
Thanks for all your help

Alex

 

[rburke]

This is what I understand from your network:

internet
|
Gateway (2610)
|
LAN 1----(router in question)------LAN 2

I'm sure that it is much more complicated, but that is the jist of what I understand minuw all the switches hubs etc.

The problem that I see is that you will need the 2 ethernet interfaces to connect LAN 1 to LAN 2, but then you would need a third ethernet interface to connect the (unknown router) to the 2610 to get to the internet. Is this a correct assumption of the skeleton of the network we are talking about? Let me know and we'll see what we can do.... Sorry about all the questions, just trying to figure out the best solution for you....

burke

 

[Guntha]

That is pretty much what I need to get done while still being able to have the Engineers get out thru the 2610. You have been a great help , Thank you very much!!

Alex