Use of Router Alert Label MPLS applications

[KATTUBAVA E.S]

Hi Experts,

Can some one help me to understand use case of Router Alert Label?

Is this label present as TOP Label for all L3VPN/L2VPN data flow across MPLS backbone? (or) is there any special use case for using this label in MPLS backbone?

Thanks in advance

-KB

[KATTUBAVA E.S]

Can someone help me to understand the usecase of router alert label in L3VPN/L2VPN?

thanks

-KB

[Nagendra Kumar Nainar]

Hi,

The forwarding semantic associated with Router Alert label is to consider it as exception for packet processing. So any packet received with RA label will be punted to CPU for processing.

The current usage of Router Alert label is for LSP Ping. More specifically, for Pseudowire LSP Ping. This is to help egress PE differentiate OAM packet from data frames (on PW) and make sure it is not leaked out of the domain.

HTH

-Nagendra