Administrator Guide

Link Aggregation 1091
A Complete MLAG Example
The following example configures eight VLANs (10–17) across two VPCs.
VPC 1 is connected to a Dell EMC Networking N2048 over two links
(gi1/0/23-24) over port-channel 2 on each MLAG peer. Interfaces Te1/0/1-2
on each MLAG peer connect to each other on port-channel 1 utilizing LACP.
UDLD is enabled on the two MLAG peer-links and the timers are configured
to the minimum values. DCPDP is enabled on VLAN 100 (interface gi1/0/8
on each MLAG peer). VLAN 100 is excluded from any MLAG interface,
including the peer-link.
VPC 2 is connected to a legacy Cisco 3750 over port-channel 3 on each
MLAG peer, and is also running LACP. The Cisco configuration is shown for
completeness.
Spanning tree instance 0 is configured for VLAN 1. Spanning tree instance 1
is configured for VLANs 10–17. Spanning-tree instance 2 carries VLAN 100
traffic on a redundant link between the two MLAG peers. The Cisco 3750
acts as the root bridge for the topology.
To support the redundant link using VLAN 200 running in MST instance 2
across gi1/0/8, configure the peer link with a high path cost for instance 2 on
the primary switch to discourage forwarding across the peer link. Likewise, on
the MLAG secondary switch, set the bridge priority to 0 for instance 2 to
encourage the secondary switch to select the root path. Be sure to name the
MST domain.
MLAG Peer A Configuration
Current Configuration:
• System Description “Dell EMC Networking N3024F, 6.0.0.0, Linux 3.6.5-
858bcf6e”
• System Software Version 6.0.0.0
console#configure
console(config)#vlan 10-17,100
console(config-vlan10-17)#exit
console(config)#hostname “MLAG-Peer-A”
MLAG-Peer-A(config)#slot 1/0 2 ! Dell EMC Networking N3024F
MLAG-Peer-A(config-stack)#stack
MLAG-Peer-A(config-stack)#member 1 2 ! N3024F
MLAG-Peer-A(config-stack)#exit
MLAG-Peer-A(config)#interface vlan 100