Deployment Guide

4 Congure a PIM-SM compatible VLT node as a designated router (DR). For more information, refer to Conguring a Designated
Router.
5 Congure a PIM-enabled external neighboring router as a rendezvous point (RP). For more information, refer to Conguring a Static
Rendezvous Point.
6 Congure the VLT VLAN routing metrics to prefer VLT VLAN interfaces over non-VLT VLAN interfaces. For more information, refer to
Classify Trac.
7 Congure symmetrical Layer 2 and Layer 3 congurations on both VLT peers for any spanned VLAN.
VLT Unicast Routing
VLT unicast locally routes packets destined for the L3 endpoint of the VLT peer.
This method avoids sub-optimal routing. Peer-routing syncs the MAC addresses of both VLT peers and requires two local DA entries in
TCAM. In case a VLT node is down, resiliency is provided by a timer that allows you to congure the amount of time needed for peer
recovery.
VLT unicast also assists in conict resolution by updating the routing table when a path for an existing multicast route has been changed.
You can enable VLT unicast and multicast routing across multiple congurations using VLT links. ECMP can be enabled on VLT nodes using
VLT unicast; however, ECMP is not compatible on VLT nodes using VLT multicast. You must use a single VLAN.
VLT unicast is supported on both IPV6 / IPv4 . To enable VLT unicast, both VLT peers must be in L3 mode. Static route and routing
protocols such as RIP, OSPF, ISIS, and BGP are supported. However, point-to-point conguration is not supported. To enable VLT unicast,
VLAN conguration must be symmetrical on both peers. The same VLAN cannot be congured as Layer 2 on one node and as Layer 3 on
the other node. Conguration mismatches are logged in the syslog and displayed in the output of the
show vlt inconsistency
command.
When you enable VLT unicast, VLAN wildcarding is enabled to support up to 4094 VLANs. If you enable VLT unicast, the following actions
occur:
• L3 routing is enabled on any new IP address / IPV6 address congured for a VLAN interface that is up.
• L3 routing is enabled on any VLAN with an admin state of up.
• For PVLAN, if the IP address is congured for the primary VLAN, L3 routing is enabled.
NOTE
: If the CAM is full, do not enable peer-routing.
NOTE: The peer routing and peer-routing-timeout is applicable for both IPv6/ IPv4.
Conguring VLT Unicast
To enable and congure VLT unicast, follow these steps.
1 Enable VLT on a switch, then congure a VLT domain and enter VLT-domain conguration mode.
CONFIGURATION mode
vlt domain domain-id
2 Enable peer-routing.
VLT DOMAIN mode
peer-routing
3 Congure the peer-routing timeout.
VLT DOMAIN mode
peer-routing—timeout value
value: Specify a value (in seconds) from 1 to 65535.
Virtual Link Trunking (VLT)
871