Unit 9: VRR (Virtual Router Redundancy)

Per-unit concept, checklist, and command drill page

Unit 9 of 14

Objective

Implement active-active default gateway behavior for resilient VLAN gateway services.

Concept Notes

VRR protects host gateway continuity by abstracting a virtual identity across redundant switches. The key behavior to internalize is that hosts target a stable virtual gateway while physical peers can fail independently.

In troubleshooting, correlate host ARP state, SVI status, and virtual MAC/address configuration. Gateway symptoms often surface first at hosts even when the root cause is switch-side config drift.

Coverage Checklist

Default gateway redundancy concepts and failure impact.
VRR vs VRRP behavior differences.
VIP and VMAC consistency rules.
VRR operation with MLAG and no single L2/L3 failure point.
Interface-level validation of virtual gateway state.

Practice Outcomes

Keep VIP and VMAC identical across peers while preserving unique SVI addresses.
Validate gateway continuity during peer or link failures.
Confirm host ARP behavior maps to expected virtual identity.

Command Drills

nv set interface vlan2 ip vrr address 172.16.2.254/24 && nv set interface vlan2 ip vrr mac-address 00:00:5e:00:01:02

Configure deterministic virtual gateway identity.

nv show interface

Verify SVI and virtual gateway interfaces are operational.

Navigation

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