The following CLI command enables the configuration on the PCC of a second PCEP session to the secondary backup PCE peer. A preference parameter value is used to indicate the primary or the secondary backup PCE peer role:
# configure router pcep pcc peer ip-address [preference preference]
A maximum of two PCE peers are supported. The PCE peer that is not in overload is always selected by the PCC as the active PCE. However, if neither of the PCEs are signaling the overload state, the PCE with the higher numerical preference value is selected. In case of a tie, the PCE with the lower IP address is selected.
To change the value of the preference parameter, the peer must be deleted and recreated.
CPROTO channels are established through the management port and, by default, use the local system address and open TCP port 4199 on both the primary and secondary VSR-NRCs.
In addition, the NRC-P always provides the active VSR-NRC acting as a CPROTO server with the system address of the mate VSR-NRC which to initiate the CPROTO channel to. The address is provided using the new Global Health and Notification CPROTO channel.
NRC-P provides a configuration for the primary VSR-NRC. This is the preferred active VSR-NRC. The other VSR-NRC is secondary. It is recommended to set the VSR-NRC co-located with the NRC-P as the primary VSR-NRC to take advantage of lowest latency and more reliable CPROTO channel.
In Figure 1, the primary VSR-NRC in the local site is VSR-NRC-A and the secondary VSR-NRC in the remote site is VSR-NRC-B. The reverse configuration is performed in the remote site. With single-site VSR-NRC redundancy, both VSR-NRCs are local and either can be configured as the primary VSR-NRC.