Cisco 1811 routing question

[acole1]

Can a Cisco 1811 router (8xLAN, 2xWAN), route on the LAN ports. Or do they only operate in switch mode?

I am wanting to use the 1811 as the default gateway for three networks (192.168.1.0, 192.168.2.0, and 192.168.3.0).

I want them to all route through the 1811 to get to each other, and have another port go out to the MPLS router.

Will the LAN ports route like this?

Right now we are using an 1841, but it only has two FE ports, and HWIC's are ~$600, so it's almost cheaper to get a new 1811 than a HWIC for an 1841.

 

[imagoon]

1811 LAN ports are switched ports.

Do all those networks need to talk to each other? If so the 1800 series is going to be pretty slow. They are at heart WAN routers and have a forward rate that matches that.

 

[acole1]

Yes, they do all need to talk to each other. One network contains DHCP PC's, one is servers and printers, and the other is the VOIP phone network.

Do you have a suggestion for another router?

At this location we have about 100 PC's and thin clients, 30 printers, and 20 servers. About the same number of PC's and printers across three other locations. This would be the default gateway for everything.

 

[ScottFern]

If you can VLAN each switchport than I think you can do it. I am not sure if that router has VLAN capabilities since its like an entry level router?

 

[acole1]

We had considered doing VLANs, but there are an insufficient number of network drops, so there are many small SOHO switches strewn around that would not support VLANs. AFAIK, all switches in the network must support VLANs. This is why we were wanting to go with physically separated subnets.

 

[imagoon]

With that much load you need a better core router that an 1811. I am digging around trying to find specs for that as I only have 1841's to go on here. It seems that you could use vlan based routing on it, I can't seem to find a rate for it. The 1800's have tons more processor power than the 1700 series though so it might be able to maintain 100mpbs routed. Dunno what will happen if you need to use anything like NAT / VPN at the same time though.

 

[acole1]

NAT and VPN are done on another router, so this one will only be used for routing between these networks. It will passing internet or WAN traffic on to other routers.

 

[jlazzaro]

1811 may work, depends on the traffic characteristics...packets will be forwarded with CEF so you should have decent performance. 1811 does 70k pps and 35Mbps with 64-byte packets...expand that to 1500-byte packets and you get the idea. as for the port operation, they are switchports only with the routing being performed via L3 SVI interfaces.

which VoIP system do you use? i assume you're trying to use the 1811 because its existing equipment. you should really look into implementing a L3 switch (3550 or 3560). if you already have other routers doing WAN/NAT/VPN, the 1811 is out of place. this will also put you in a good position to start nixing the daisy chained soho switches...they will be the end of you

alternatively, you could simply buy a L2 switch capable of trunking and use the MPLS router as a router on a stick. hard to say for certain without knowing more about your infrastructure.

 

[Pheran]

Performance specs are here; the 1811 is almost identical (very slightly slower) in performance to an 1841:

http://www.cisco.com/web/partn.../routerperformance.pdf

The Mbps numbers they give are based on minimum packet sizes, so you can expect better than that in real world performance with large packets. Still, these are not particularly powerful routers, since they are SOHO devices.

You can certainly use VLAN interfaces on the router to route between several networks; this doesn't require every switch to support VLANs. Whether or not the performance is sufficient for what you want to do is another question entirely.

 

[drebo]

I wouldn't consider a Cisco 1800 series router a SOHO router. As explained earlier, it's more of a WAN router. $1500 is a bit more than any SOHO is going to spend for a router.

 

[imagoon]

Originally posted by: drebo
I wouldn't consider a Cisco 1800 series router a SOHO router. As explained earlier, it's more of a WAN router. $1500 is a bit more than any SOHO is going to spend for a router.

Exactly 50 users is not "small" any more. Anyway these routers are decent but I would not direct server traffic through them (at LAN speeds). I had something like what you are trying to do set up at a 36 station office however it was to segregate voice from data and to handle WAN. Servers stayed on the same subnets as the clients. The router performed perfectly with this config.

It is important to test it with your proposed environment first. 70,000PPS @ 64bytes represents about 35Mbps. This is with no options enabled. Depending on how the switch is designed, it might be using the same CPU so using it can lower the rate. Enabling any features with also lower this rate.

Any way, I personally use 3750G layer 3 switch routers to handle my core stuff. The 3550 etc is also good depending on cost and needs. The 1811 really should be used to handle the WAN only.

 

[Pheran]

Originally posted by: drebo
I wouldn't consider a Cisco 1800 series router a SOHO router. As explained earlier, it's more of a WAN router. $1500 is a bit more than any SOHO is going to spend for a router.

Point taken, I'm probably abusing the "SOHO" classification a bit. I'm just making the same point everyone else is - this wasn't really meant to route LAN traffic unless your LAN demands are pretty damn low. Cisco classifies the 1800 series as "small branch" routers.

 

[acole1]

We are using a 3560 for the few VOIP phones we currently have. It routes between the phone and primary subnets currently. This may be a good solution to the problem. We will just have to convince management the extra expense is justified.

 

[spidey07]

Originally posted by: imagoon

Originally posted by: drebo
I wouldn't consider a Cisco 1800 series router a SOHO router. As explained earlier, it's more of a WAN router. $1500 is a bit more than any SOHO is going to spend for a router.

Exactly 50 users is not "small" any more. Anyway these routers are decent but I would not direct server traffic through them (at LAN speeds). I had something like what you are trying to do set up at a 36 station office however it was to segregate voice from data and to handle WAN. Servers stayed on the same subnets as the clients. The router performed perfectly with this config.

It is important to test it with your proposed environment first. 70,000PPS @ 64bytes represents about 35Mbps. This is with no options enabled. Depending on how the switch is designed, it might be using the same CPU so using it can lower the rate. Enabling any features with also lower this rate.

Any way, I personally use 3750G layer 3 switch routers to handle my core stuff. The 3550 etc is also good depending on cost and needs. The 1811 really should be used to handle the WAN only.

I was going to suggest something similar. Using it to separate your voice and data networks is fine as there isn't much traffic that would go between them, keep voice servers and phones on the voice vlan and data/clients on the data vlan.

But asking it to route lan speeds is asking for performance problems. It's a WAN router, that's what it should be doing. This gets into the finer aspects of network design and planning - just because you "can" do something doesn't mean you "should".