Connecting To A Router In A Vpc Topology - Cisco Nexus 5000 Series Operation Manual

Connecting to a Router in a vPC Topology

S e n d d o c u m e n t a t i o n c o m m e n t s t o n 5 k d o c f e e d b a c k @ c i s c o . c o m
Figure 2-5
L3
L2
Note
Only the Layer 3 traffic needs to cross the peer link. The VLAN traffic is switched by N5k-2 locally.
The peer gateway is disabled on both vPC switches if the Layer 3 module fails on one switch.
For topologies with in-band management, the failure of a Layer 3 module means that the connectivity to
the management network and the management system is also lost.
Connecting to a Router in a vPC Topology
When you connect a router to a pair of Cisco Nexus 5500 Platform switches in a vPC topology and
enable routing, traffic forwarding may result in suboptimal traffic paths crossing the peer link similar to
the situation described in the
on page
5500 switch, instead of a port channel with an IP address.
Figure 2-6
may be hashed by the port channel to the wrong Cisco Nexus 5500 Platform switch, which would then
forward the control packets to the correct routing peer (1.1.1.1) in the picture.
Cisco Nexus 5000 Series NX-OS Interfaces Operations Guide, Release 5.0(3)N2(1)
2-6
Layer 3 Module Failure
L3 network
N5k-1
"Layer 3 Forwarding for Packets to a Peer Switch MAC Address" section
2-2. We recommend that you use Layer 3 links for connections between the router and the Nexus
illustrates the topology that is not recommended. In this topology, control protocol packets
Chapter 2 Cisco Nexus 5500 Platform Layer 3 and vPC Operations
N5k-2
x