I can hardly believe that. How do you know?

Marcel

Hi Marcel

You can check it by using the "show interface vlan x" command.

For me it showed 1000000kbits per second (1 Gbps) on a 6509 and a 4948.

Cheers:

Istvan

This is the administrative bandwidth, used by eg OSPF and EIGRP to make routing decisions.

I mean the real bandwidth, or speed (as used with real ethernet), or clock rate (used with serial lines).

That administrative BW can be changed with the interface command: bandwidth [1..10000000]

Marcel

Hi Marcel,

This is true, it is the administrative bandwidth.

Physically you can be connected to a Fastethernet, Gigabitethernet or a Tengigabitethernet interface. The physical connection will give you the real bandwith you can have.

Cheers:

Istvan

Marcel

I believe that there is a logical fallacy in your question. You ask:

"I mean the real bandwidth, or speed (as used with real ethernet), or clock rate (used with serial lines)."

but real bandwidth (or real speed) exists only on physical interfaces. A SVI is a virtual interface and as such does not have a real bandwidth. If anything the bandwidth of a SVI is the bandwidth of the backplane of the switch.

HTH

Rick

True, but I did not want to influence your answers.

What I've learned from several documents on CCO, that an SVI is using the backplane. On a cat6500 this is a 6 Gbps EtherChannel.

Is the folllowing correct:

All SVIs share the available bandwidth of 6 Gbps of the backplane.

The thing I try to get clear is related to the following configuration:

I have an FWSM in the cat6500, with multiple virtual firewalls. At this moment each outside interface of the firewall has it's own SVI on the router.

If I combine all outside interfaces on one SVI (all outsides are in the same L3 subnet), does this impact the available bandwidth?

How about SVI-SVI traffic, and FW-FW traffic?

As you can see, there is no physical port involved. The physical ports are all behind the firewalls.

I know I can configure QoS on the different FW-contexts, but this question is about the bandwidth on the router (or MSFC).

Looking forward to your insights!

Marcel