HSRP, VRRP, and GLBP all solve the same problem - first-hop redundancy for end-host gateways - but they make different trade-offs. HSRP is Cisco's default, simple and widely deployed. VRRP is the open standard, vendor-neutral, slightly faster failover. GLBP is Cisco's load-balancing variant, more complex but utilizes multiple routers simultaneously. The right choice depends on what is in your network, what your operators know, and whether load balancing matters.
This article walks through the side-by-side differences, the design implications, and the specific scenarios where each is the right answer. If you are choosing an FHRP for a new deployment or auditing an existing one, this is the comparison.
The Side-by-Side Table
| Trait | HSRP | VRRP | GLBP |
|---|---|---|---|
| Standard | Cisco-proprietary (RFC 2281 informational) | IETF (RFC 5798) | Cisco-proprietary |
| Vendor support | Cisco only | Universal (Cisco, Juniper, Arista, Nokia, etc.) | Cisco only |
| Active/standby vs Active/active | Active/standby (one router forwards) | Master/backup (one router forwards) | Active/active (up to 4 forwarders) |
| Load balancing | Per-VLAN (different active per VLAN) | Per-VLAN | Per-host (within VLAN) |
| Default Hello | 3 seconds | 1 second | 3 seconds |
| Default Hold/Dead | 10 seconds | 3 seconds | 10 seconds |
| Multicast address | 224.0.0.2 (v1) / 224.0.0.102 (v2) | 224.0.0.18 | 224.0.0.102 |
| Virtual MAC | 0000.0c07.acXX | 0000.5e00.01XX | 0007.b400.GGFF |
| States | 6 (Initial, Learn, Listen, Speak, Standby, Active) | 3 (Initialize, Backup, Master) | 6+ (per-AVG and per-AVF) |
| Authentication | Plain text or MD5 | None in v3 (deprecated v2 had MD5) | MD5 |
| IPv6 support | HSRPv2 with IPv6 group | VRRPv3 native | Yes, IPv6 group support |
| Object tracking | Yes | Yes | Yes (weighting tracking) |
| Configuration complexity | Low | Low | Medium-high |
| Operational maturity | Very high (decades of Cisco deployment) | High | Medium (less common) |
When HSRP Wins
- You are a Cisco-only shop. HSRP is the default, well-understood, and universally documented for Cisco networks.
- Your operators are HSRP-trained. Switching to VRRP for marginal benefits is rarely worth retraining.
- You want simple operations. The HSRP state machine is more verbose than VRRP's but the configuration is straightforward and troubleshooting tools are mature.
- You inherited an HSRP deployment. Migrating to something else is rarely justified by performance or cost.
When VRRP Wins
- Multi-vendor environment. Mandatory if any non-Cisco router participates in the FHRP group.
- Faster default failover matters. VRRP's 3-second Hold (vs HSRP's 10) gives sub-second improvement in failure detection.
- You want IETF-standard protocols across the board. Operational discipline / vendor neutrality preference.
- VRRPv3 IPv6 design. Modern VRRPv3 is cleaner for IPv6 than HSRPv2.
When GLBP Wins
- You specifically need active/active gateway forwarding without per-VLAN tuning. The single use case GLBP genuinely wins on.
- Cisco-only with homogeneous routers. GLBP needs Cisco and works best with similar capacity routers.
- You have idle redundant capacity and want to use it.
In practice, GLBP shows up less often than its capabilities suggest. Most Cisco campus designs use HSRP with different active gateways per VLAN, which achieves load distribution at the VLAN level without GLBP's complexity.
Failover Times Compared
| Scenario | HSRP | VRRP | GLBP |
|---|---|---|---|
| Default timers, link-down | ~10 seconds | ~3 seconds | ~10 seconds |
| Tuned timers (Hello 1s / Hold 3s) | 3 seconds | 3 seconds (already) | 3 seconds |
| Sub-second tuning | ~750ms (Hello 200ms / Hold 750ms) | ~750ms | ~750ms |
| BFD-tracked (with FHRP) | ~50-200ms | ~50-200ms | ~50-200ms |
With BFD object tracking, all three FHRPs converge in similar timeframes. Default timers favor VRRP, but tuning equalizes them.
Design Impact
The most common production pattern across all three:
- Two distribution switches per VLAN
- FHRP (HSRP, VRRP, or GLBP) configured for the VLAN
- Object tracking on upstream interface to decrement priority/weighting on uplink failure
- STP root alignment with the active FHRP gateway per VLAN
- For HSRP/VRRP: alternate which switch is active per VLAN to spread load
- For GLBP: both switches active in the same VLAN, hosts distributed automatically
HSRP and VRRP achieve load distribution by being active on different VLANs on different switches. GLBP achieves it within a single VLAN by distributing hosts across forwarders. Operationally HSRP/VRRP per-VLAN is more common because it integrates cleanly with STP per-VLAN root assignment.
For STP-FHRP alignment patterns, see Spanning Tree and First-Hop Redundancy.
Migrating Between FHRPs
Migration paths exist but are operationally fragile:
| From | To | Approach |
|---|---|---|
| HSRP | VRRP | Configure VRRP alongside HSRP on different group numbers; verify; migrate hosts (DHCP) to new virtual IP; remove HSRP |
| HSRP | GLBP | Same approach but GLBP needs more careful timer tuning; rarely justified |
| VRRP | HSRP | Reverse of HSRP-to-VRRP; only do this if removing non-Cisco gear |
The "configure new alongside old, migrate, remove" approach minimizes disruption. Both FHRPs run simultaneously on different group numbers; hosts use the old gateway IP until DHCP renews them to the new gateway IP.
Recommendations
Default recommendations for typical scenarios:
| Scenario | Recommendation |
|---|---|
| Cisco-only campus, new deployment | HSRP. Simpler, well-understood, mature. |
| Multi-vendor environment | VRRPv3. Mandatory. |
| Cisco-only, want active/active without per-VLAN tuning | GLBP. The one case it genuinely wins. |
| Existing HSRP deployment | Stay with HSRP unless multi-vendor migration forces VRRP. |
| Existing VRRP deployment | Stay with VRRP. Migrating to HSRP is regress. |
| Greenfield IPv6-only | VRRPv3. Cleanest IPv6 story. |
Summary
HSRP for Cisco-only simplicity. VRRP for multi-vendor and IETF-standard preference. GLBP for the specific case of active/active without per-VLAN tuning. All three converge similarly when tuned with BFD; default timers favor VRRP slightly.
The right answer is mostly determined by what is already in your network. Most enterprises run HSRP because they were Cisco-shops and HSRP was the default; few have a real reason to migrate. Bookmark this article alongside the FHRP cluster pillar, the VRRP article, and the GLBP article.