Adv. of HSRP over GLBP

moabdallah · ‎08-23-2007

What is the advantage of HSRP over GLBP ?

Regards

Mohamed

jwdoherty · ‎08-23-2007

The advantage of HSRP over GLBP, not the converse? Don't know if these are true advantages, but have seen an issue with GLBP if you have some other Brand X equipment in the mix, as in the Brand X switches couldn't find the gateway any longer (this too after refreshing ARP tables). However, user traffic, i.e. not sourced from the switch itself, found the gateway(s).

With GLBP, also need later equipment or IOS images that support it.

One issue of importance where HSRP might be an better choice over GLBP is if you're doing NBAR classification of stateful traffic. To get this truly right I believe you need to avoid asymmetrical paths. Since GLBP spreads the uplink path, this becomes difficult.

moabdallah · ‎08-23-2007

What about running voice traffic over HSRP or GLBP ?

jwdoherty · ‎08-23-2007

Haven't seen a difference since both provide a virtual gateway. Only issue, again with both, is failover might not be fast enough to keep a voice call up. GLBP and it's millisecond timers might be of benefit for that, as would HSRP V2. Or HSRP V1 running on a redundant hardware box that supports NSF. (For the latter, you would think HSRP wouldn't be necessary, but a second platform covers unlikely total box crashes.)