Cisco 6509 switch w/MSFC card vs a router?

[JEDI]

A 6509 w/msfc is basically a router, but FASTER since it operates at the data layer (layer 2). Advantages/disadvantages of just using 6509's w/mfsc instead of a regular router?

THX

 

[spidey07]

The biggest reason is performance.

I believe the msfc can forward frames at 30 million packets per second. Also the msfc is a true router in the sense that it operates at layer3 and even layer4.

There really are no disadvantages that I can think of. If you have a 6509 you generally put a msfc in it to handle the routing.

 

[Lord Evermore]

Anything that only operates at Layer 2 can't be a "router" of any sort, since IP is Layer3. You can't "route" MAC addresses. However using only Layer 2 for switching should theoretically be faster than using routing since the processor doesn't have to do as much work. But I'd expect a slower processor in a switch than in a router, so the performance difference would be made up.

 

[SgtBuddy]

Just to throw this in.

Using VLANs (ISL, dot1q, yadda yadda) to "route" would only be a Layer 2 operation..right? Or are VLAN capable switches actually using "Layer 3 switching"?

 

[alrox]

A MSFC/MSFC2 equipped 6500 series router will let you create logical vlan interfaces and assign IP's to these interfaces and do everything a 'router' can do. A MSFC is basically a npe-200 blade from the 7200 series, same CPU and everything.

It is a 'layer 3 switch', 'routing switch' or whatever marketing term you wish to use.

 

[JEDI]

so why buy a router if a 6509 w/msfc can handle the job and handle it faster?

 

[spidey07]

Port adapter density is the primary reason.

You can get a WAN blade for the 6500 that has two port adapter slots for things like T3, HSSI, Serial, T1 or OC3. But many times you'd rather get a 7206 because it has 6 slots.

Also many times networks are built in a modular fashon where the LAN switches/routers only have to worry about lan routing, the WAN routers then only worries about WAN routing...it helps when the network starts to grow and you deal with modular pieces/blocks instead of individual gear.

 

[Garion]

Originally posted by: spidey07
Port adapter density is the primary reason.

You can get a WAN blade for the 6500 that has two port adapter slots for things like T3, HSSI, Serial, T1 or OC3. But many times you'd rather get a 7206 because it has 6 slots.

Also many times networks are built in a modular fashon where the LAN switches/routers only have to worry about lan routing, the WAN routers then only worries about WAN routing...it helps when the network starts to grow and you deal with modular pieces/blocks instead of individual gear.

Cost is also a huge factor - A loaded 6509 is way, way expensive - With L3 capacity, WAN blades and all the port adaptors, you're looking at well over $100K. A full loaded 7206 can be purchased for less than $30K.

- G

 

[Santa]

And don't forget redundancy.. You should start moving twords building more smaller boxes that are redundant than very large singular core boxes.

While it is possible to run everything/your whole company off of the Layer 3 Switch you wouldn't want to.

As Spidey mention modular design will help you isolate traffic and leave room in the chassis for growth.

Don't forget also if you don't need the extra power why pay for it? Pay for redundacy and your way ahead of the game.

 

[spidey07]

And to santa's point...

I can build the most beautiful, powerful networks the budget will allows.

BUT!!!! There is more to building networks than simplicity and beauty. What is simple for a few hardcore network guys is NOT simple for most others. So having a modular design allows for easier support/maintenance.

If you slam all of your routing into a 6500 or two then what happens when a 6500 fails (and it will)? Can you still provide service without that 6500? What services are impacted?

So apart from the performance and technology alone there are other aspects to why you would want your routing somewhere else...Garion's cost issue being a big one.

 

[cmetz]

A MSFC card gets you a router with the stability of a 6509. Woo-hoo.

The main reason to do it is one box. A lot of sites like that. One box is a heckova lot easier to manage than many.

The main reasons not to do it are cost and reliability. You can likely get an outboard router of the flavor you actually need for less money, and it'll be more reliable that way.