What exactly does configuring protocols mpls do? I've done some testing in the lab and here's what I observed:
LDP LSPs - Does not require protocols mpls
RSVP LSPs - Requires protocols mpls
LDP signalled VPN - Requires protocols mpls on PEs
BGP signalled L3VPN - Does not require protocols mpls
One of my PEs is an MX running 15.x, and other PE is an SRX running 12.x. So it's not a platform or code specific issue. Can anyone explain why protocols mpls is required for RSVP but not LDP LSPs? Why it's required for LDP signalled VPNs, but not BGP signalled L3VPN?