IPv4 and VPNv4 labels

[wfgeorge3]

I'm learning about MPLS and just had a quick question- 

Does the LDP and BGP processes in IOS somehow tell each other what labels they have assigned to avoid conflicts for the label IDs?

[Vinit Jain]

Hello,

you can use the command show bgp <afi> <safi> labels command to check the BGP assigned labels. MPLS as you know, do not assign for labels for BGP learnt prefixes. It will only assign labels for IGP learnt prefixes.

Regards

Vinit

[wfgeorge3]

Hello,

That I know, but I was trying to figure out if an egress PE advertises a label to another PE, what happens if that label is used by the egress PE for something else too. Is that possible?

[Vinit Jain · Accepted solution]

Thanks for the reply. if a device allocates a label be it IGP or VPN label, that label is unique on the system. the labels allocated by BGP or LDP are from a common pool of labels. it is not like BGP has a seperate label space and LDP has a separate one. if there is an IGP label, it will be used for forwarding purpose or building the LSP in other words. If a VPN label is allocated, it will be used for VPN purpose only. 

Please let me know if that answers your question or if i understood it differently.

Regards

Vinit

[wfgeorge3]

Thanks for the clarification.