Users Guide

Layer 2 Switching Commands 653
User Guidelines
Changes to the DCPDP configuration do not take effect until the protocol is
disabled and then re-enabled. Both the local switch and the MLAG peer
switch must be configured identically. The recommended procedure to
update these parameters is to disable the DCPDP protocol on both switches,
configure the new parameters on both switches, and then re-enable the
DCPDP protocol on both switches.
The Dual Control Plane Detection Protocol is a UDP-based protocol. The
administrator must configure this protocol on an IP interface with a VLAN
that is not shared with any of the MLAG interfaces. This can include the out-
of-band port. When enabled, the dual-control plane detection protocol sends
a control plane detection message to the peer once every second. The
message is unidirectional and contains the sender’s MAC address. When a
switch receives a control plane detection message it sets the ‘peer is UP’
variable to TRUE to indicate that a peer is detected.
Do not configure DCPDP to use a port reserved by the switch. UDP, TCP and
RAW ports reserved by the switch and unavailable for use or configuration
are:
Ports 1, 17, 58, 255, 546, 547, 2222, 4567, 6343, 49160
Example
console(config)#vpc domain 1
console(config-vpc 1)#peer-keepalive enable
console(config-vpc 1)#peer-keepalive destination 192.168.0.2 source
192.168.0.1
console(config-vpc 1)#peer detection enable
console(config-vpc 1)#exit
peer-keepalive enable
Use the peer-keepalive enable command to enable the peer keepalive
protocol on the peer link. When enabled, if an MLAG switch does not receive
keepalive messages from the peer within the timeout value and DCPDP is
disabled, the switch begins the process of transitioning to the primary role (if
standby).
Use the no form of the command to disable the peer keepalive protocol.