FHRP Visualizer
Interactive HSRP, VRRP, and GLBP Explorer
FHRP Protocol Comparison
Side-by-side comparison of HSRP, VRRP, and GLBP:
HSRP
Hot Standby Router Protocol
Vendor:
Cisco Proprietary
RFC/Standard:
None (Cisco only)
Active Routers:
1 (Active/Standby)
Multicast (v1):
224.0.0.2
Multicast (v2):
224.0.0.102
Transport:
UDP 1985
Virtual MAC (v1):
0000.0c07.acXX
Virtual MAC (v2):
0000.0c9f.fXXX
Hello Timer:
3 seconds
Hold Timer:
10 seconds
Default Priority:
100
Preemption:
Disabled (manual)
Load Balancing:
No
VRRP
Virtual Router Redundancy Protocol
Vendor:
Open Standard
RFC/Standard:
RFC 5798
Active Routers:
1 (Master/Backup)
Multicast:
224.0.0.18
Multicast (v2):
N/A
Transport:
IP Protocol 112
Virtual MAC:
0000.5e00.01XX
Virtual MAC (v2):
N/A
Advertisement:
1 second
Hold Timer:
3 × Advertisement
Default Priority:
100
Preemption:
Enabled (default)
Load Balancing:
No
GLBP
Gateway Load Balancing Protocol
Vendor:
Cisco Proprietary
RFC/Standard:
None (Cisco only)
Active Routers:
Up to 4 (AVG/AVF)
Multicast:
224.0.0.102
Multicast (v2):
N/A
Transport:
UDP 3222
Virtual MAC:
0007.b400.XXYY
Virtual MAC (v2):
N/A
Hello Timer:
3 seconds
Hold Timer:
10 seconds
Default Priority:
100
Preemption:
Disabled (manual)
Load Balancing:
Yes (round-robin)
Key Differences Summary
- HSRP: Cisco-only, most common in enterprise, simple active/standby model
- VRRP: Open standard for multi-vendor environments, preemption enabled by default
- GLBP: Cisco-only with load balancing, uses multiple virtual MACs for distribution
HSRP State Machine Simulator
Click on states to see the HSRP state transition sequence:
Initial
→
Learn
→
Listen
→
Active
←
Standby
←
Speak
State: Initial
Description: Starting state when HSRP first starts or the interface comes up.
Behavior: HSRP is not running yet. Interface is being configured.
Next State: Learn (if virtual IP not configured) or Listen (if virtual IP is configured).
Complete State Reference
| State | Description | Sends Hellos? | Forwards Traffic? |
|---|---|---|---|
| Initial | Starting state, HSRP beginning | No | No |
| Learn | Waiting to learn virtual IP from active router | No | No |
| Listen | Listening for hello messages | No | No |
| Speak | Participating in active/standby election | Yes | No |
| Standby | Backup router, ready to take over | Yes | No |
| Active | Forwarding router for virtual IP | Yes | Yes |
FHRP Configuration Builder
Generate configuration for HSRP, VRRP, or GLBP:
FHRP Knowledge Check
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