balajitvk Sun, 07/29/2007 - 00:03


The configuration overhead to do the loadbalancing is nil in GLBP as it is doing automatically so we find it better utilization of link as compared to default HSRP configuration.

And also serval operational modes that GLBP supports for load-balancing

1. Weighted loadbalancing

2. Host-dependent

3. Round-robin.

is providing higher flexibility on utilization of the links.

Rate if it does,


cfajardo1_2 Sun, 07/29/2007 - 00:21

would this solves the problem below;

- 2 routers config with mhsrp (2 groups)

- having 2 virtual ip (1 for each group)

- thereby having 2 diff def gateways for clients

will glbp solves the prob by having only single ip address in this case?

Amit Singh Sun, 07/29/2007 - 00:33

Are the clients in different vlans or in the same vlan. If the clients are in different vlans, then you still have to define two groups in the GLBP config but the difference here would be that both the routers will be active for each group, so you will see an effective load-balancing across both the routers.

If all the clients are in a single vlan and you are using 2 groups and gateways for load-balancing then you can have a single group defined and both the routers will be active and doing the effective load-balancing.

-amit singh

cfajardo1_2 Sun, 07/29/2007 - 00:57

what i mean is;

- hsrp can do load balncing with 2 routers by using multi group and thereby having 2 virtual ip's whereas

- glbp can do this load balancing the 2 routers by having only single ip



balajitvk Sun, 07/29/2007 - 01:44


Yes, your understanding is right but with a difference.

In HSRP, you can do loadbalancing by using multi-group and assigning each router as active for each group. But it is not a actual loadbalancing because if one of the group having higher traffic than other, then one router/link is highly utilized than other. Moreover, you need to do this manually.

But in GLBP, it is doing loadbalancing among a single group automatically which will give true loadbalancing among routers or links.

Rate if it does,


rajatsetia Sun, 07/29/2007 - 21:09

Hi all

GLBP does provide true load balancing as explained above..

correct me if i am wrong here ...

But in a campus network where you have various VLANs, GLBP does not provide load balancing,if you span vlan across campus network i.e. distribution at L2 ....

** I know it is not best practise to span vlan across but I have seen requirements like this ..


balajitvk Sun, 07/29/2007 - 21:37

Hi Rajat,

I don't see any probs in having GLBP even if the distribution @ L2. Simillarly GLBP can be used whereever HSRP can be used and i don't see any as such restriction.


rajatsetia Sun, 07/29/2007 - 21:57


I was saying that GLBP wonnt do true load balancing as it is designed to do in this case otherwise GLBP will work in this scenario also..



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