ACE PROFESSIONAL · CAMPUS

Arista: LACP port-channel and VRRP gateway

Two Arista distribution switches are joined by two links and share the users’ gateway. Bundle the links into a LACP port-channel that trunks VLAN 10, give each switch an SVI, and run VRRP so 192.168.10.1 stays up if one switch fails. DIST1 must be master.

Arista ACE Professional track · Arista · 5 objectives

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Objectives

The simulator ticks each one as soon as the network meets it.

Create VLAN 10 on both switches and put Ethernet3 in it.
Bundle Ethernet1–2 into Port-Channel1 with LACP active on both switches, and make it a trunk for VLAN 10.
Address Vlan10: DIST1 192.168.10.2/24, DIST2 192.168.10.3/24.
Run VRRP group 1 with virtual IP 192.168.10.1; DIST1 priority-level 120 so it is master.
PC2 pings the virtual gateway 192.168.10.1.

Start this lab

Before you start

interface Ethernet1-2 configures both links at once; channel-group 1 mode active creates Port-Channel1. Trunk settings go on the Port-Channel. EOS VRRP: vrrp 1 ipv4 192.168.10.1 and vrrp 1 priority-level 120. show vrrp shows which switch is master.

Concept

EtherChannel / Eth-Trunk with LACP

Link aggregation bundles parallel links into one logical link. Spanning tree then sees a single port, so all links forward at once instead of one being blocked, and traffic moves to the remaining links if one fails.

Concept

HSRP and VRRP: a gateway that survives a failure

Hosts have one default gateway. A first-hop redundancy protocol lets two routers share a virtual IP (and virtual MAC) as that gateway: one router answers for it, the other takes over if it fails.