PlantUML DiagramHSRP vs GLBP Behavior
A structured lesson workspace with readable content, hands-on examples, and a clean path to completion.
| Feature | HSRP | VRRP | GLBP |
|---|---|---|---|
| Standard | Cisco-proprietary | IEEE 802.1 (open) | Cisco-proprietary |
| Default priority | 100 | 100 | 100 |
| Virtual MAC | 0000.0C07.ACxx | 0000.5E00.01xx | 0007.B400.xxyy |
| Active routers | 1 active, 1+ standby | 1 master, 1+ backup | 1 AVG + multiple AVFs |
| Load balancing | None natively (use multiple groups) | None natively (use multiple groups) | Native — different clients to different routers |
| Hello timer | 3 sec | 1 sec | 3 sec |
| Preemption | Off by default | On by default | On by default |
| Track objects | Yes | Yes | Yes |
The three FHRP protocols solve the same problem with different trade-offs. HSRP is Cisco-proprietary but the most widely deployed in Cisco shops. VRRP is the open standard — use it in multi-vendor environments. GLBP adds load balancing, letting different clients use different physical routers simultaneously.
HSRP's standby router is idle under normal operation. If you have heavy internal traffic, that's wasted capacity. GLBP fixes this by having different clients use different physical routers, while still presenting a single virtual IP. All routers are active — the AVG (Active Virtual Gateway) assigns clients to AVFs (Active Virtual Forwarders).
Cisco's own preferred load-balancing approach with HSRP is to run multiple groups, with different groups active on different routers. Group 1 might have R1 active, Group 2 might have R2 active. Half of your VLANs use Group 1's VIP, half use Group 2's. Both routers are productive.
Preemption determines whether a higher-priority router takes over the active role when it comes back online. If preemption is on and R1 (higher priority) fails and recovers, R1 reclaims active role from R2. If preemption is off, R2 stays active until it fails.
HSRP preemption is off by default. If you don't enable it, a recovered higher-priority router stays standby — traffic keeps flowing through the lower-priority router. Sometimes you want this (stability), sometimes you don't (expecting the best router to be active). Decide deliberately, don't just accept the default.
Configure HSRP in a two-router lab. Fail the active router and time how long the standby takes to take over (~3-10 seconds depending on timers). Then try GLBP with the same topology and see load distribution across both routers.
Finish the lesson once you have worked through the material. This awards ★ 15 XP.