[c-nsp] GLBP Groups Question

[TiM]

Hi,

Short version of question: Does putting multiple SVI's in the same GLBP
group save resources? i.e. is it more efficent to have 10 SVI's in 5 GLBP
groups, or is there no difference in resource usage?

Long version of question:

I'm looking to have ~10 3750 stacks connected to a couple of Cisco 7609s. 
To avoid any spanning tree hassles, a vlan on one stack will not appear on
any other stack.  A decision has been made to keep the management of the
3750's in a seperate VLAN, therefore I'll need ~10 extra vlans to manage
all 3750 stacks.

Therefore, assume that each stack has a Data, Voice and Management VLAN.

I'm going to be running GLBP on the 7609's, so that traffic is spread over
the 7609s and there is redundancy in th event of 7609 failure.

In order to ensure that I can always manage a 3750 Stack, I'm going to be
adding the Management VLAN into GLBP as well.  Will the extra 10 GLBP
sessions add extra CPU overhead/load to the 7609s?  Using the group
feature, if I have a group 10 for Stack 1, group 20 for stack 2 etc, does
adding the Management VLAN to that group save on CPU/keepalive traffic?

Really my question boils down to:

Is this configuration:

interface Vlan10
 description Data Stack 1
 ip address x.x.x.x 255.255.255.0
 glbp 10 ip x.x.x.x
!
interface Vlan11
 description Management Stack 1
 ip address y.y.y.y 255.255.255.0
 glbp 10 ip y.y.y.y

anymore efficent than this configuration:

interface Vlan10
 description Data Stack 1
 ip address x.x.x.x 255.255.255.0
 glbp 10 ip x.x.x.x
!
interface Vlan11
 description Management Stack 1
 ip address y.y.y.y 255.255.255.0
 glbp 11 ip y.y.y.y

Many Thanks,
Tim