Dell Networking N4000 Series Configuration Manual page 947

MLAG domain for the MLAG feature to automatically utilize the peer-link to
forward packets around failures. MLAG VLANs may have IP addresses
assigned, but MLAG VLANs cannot be used to route across MLAG or non-
redundant VLANs, as the MLAG feature does not correlate failures in one
VLAN with another VLAN to unblock packets crossing the MLAG peer-link.
Recommended L3 Connectivity
The topology shown in Figure 28-12 uses the MLAG switches as L2 switches.
All VLANs traverse the MLAG topology from the top switches/routers to the
bottom switches/routers. The LAGs for each VLAN host are in a separate
VPC. The router sees the port-channel as a single logical interface with
multiple VLANs. This topology is highly recommended as it utilizes MLAG
in the scenario for which it was intended (redundant full-bandwidth
replacement for spanning tree) and allows the MLAG peers to detect failures
and unblock the appropriate VLANs on the peer link so that traffic flow can
continue unimpeded.
Figure 28-12. Recommended L3 Connectivity
L3 Router
Failed Link MLAG
VLAN 10, 20, 30
Peer-Link
MLAG Router Peer MLAG Router Peer
MLAGs
VLAN 10 VLAN 20 VLAN 30
Host Host Host
947
Configuring Link Aggregation