I was wondering how would load balance will work for a layer 3 switch acting as a router for inter-vlan. Like for instance, router 1 and router 2 were configured for glbp and a host that resides in vlan 10 initiate a traffic - will forward the request to its default gateway (which is the layer 3 switch), and the layer 3 switch will then forward to the forwarding router (for example router 2).

HSRP/VRRP and GLBP do not work the same way because they offer slightly different services. For HSRP/VRRP, only one router is Active/Master at one point. It answers all the ARP requests sent to the virtual IP (vIP) with the Virtual MAC (vMAC) of the group as both the MAC Source address of the frame and the ARP Sender MAC Address.

Also, just personally, if i had a non Cisco router in the mix (which i would never do ) i would just stick with VRRP on all routers rather than confuse things by using multiple FHRP's. And if its Cisco, then you might as well use GLBP and load balance without adding additional config and multiple default gateways.

GLBP is something completely different: it allows to loadbalance traffic to different devices (as the name implies: "Gateway LoadBalancing Protocol"). Even if GLBP also provides some kind of redundancy, it's primary purpose is different than the primary purpose of HSRP or VRRP.

To configure the time between hello packets sent by the Gateway Load Balancing Protocol (GLBP) gateway and the time that the virtual gateway and virtual forwarder information is considered valid, use the glbp timers command in interface configuration mode.

HSRPv2 & GLBP both have the same multicast address of 224.0.0.102. Even if it's rare, what would happen if you're running BOTH at the same time?

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then removed it R9 (config-if)#no glbp 1 load-balancing R9 (config-if)#do sho glbp de Ethernet0/0 - Group 1 State is Init (virtual IP in wrong subnet) Virtual IP address is 10.1.1.1 (wrong subnet for this interface) Hello time 3 sec, hold time 10 sec Redirect time 600 sec, forwarder timeout 14400 sec Preemption disabled Active is unknown ...

GLBP uses the hello messages to communicate the current state of the timers. The redirect time is the interval during which the AVG continues to redirect hosts to the old virtual forwarder MAC address.

I configured glbp group 20 on vlan 20 under fa0/0.20, only has an active router, while the second router is in init state. Hmm..I did not see anything wrong with the config on fa0/0.20, I have activated glbp 20 on fa0/0.20 on 2nd router, anything I missed out?