Disabling CSPF path calculations
By default, CSPF is enabled for signaled LSP calculations, but you can disable CSPF. For example, to allow a TE tunnel LSP to traverse OSPF areas, disable CSPF.
Disabling CSPF means that the full CSPF path is not computed up front. Instead, the vRouter queries the RIB for the next-hop information. This information is needed to reach the egress vRouter. Then, the vRouter sends the RSVP PATH message to the next hop without an Explicit Route Object (ERO). A similar process occurs at each hop along the path.
If you configure a full or partial explicit path, the vRouter queries the RIB for the next-hop information to reach the first hop in the explicit path. The vRouter sends the RSVP PATH message with an ERO whose first hop is the actual first next hop, and whose subsequent hops are from the configured path. Each hop along the path removes the first hop from the ERO and performs a RIB lookup on the next hop in the list.
To disable constraint-based path selection for a TE tunnel, use the following command:
set protocols mpls-rsvp tunnels tunnel name { primary | secondary } no-cspf
vyatta@vyatta# set protocols mpls-rsvp tunnels tunnel tunnel1 primary no-cspf
vyatta@vyatta# set protocols mpls-rsvp tunnels tunnel tunnel1 secondary no-cspf
vyatta@vyatta# commit
vyatta@vyatta# show mpls rsvp session detail
Ingress (Primary)
6.6.6.6
From: 1.1.1.1, LSPstate: Up, LSPname: tunnel1
Ingress FSM state: Operational
Setup priority: 7, Hold priority: 0
CSPF usage: Disabled
Reoptimization: Disabled
IGP-Shortcut: Disabled, LSP metric: 65
LSP Protection: None
Label in: -, Label out: -
Tspec rate: 0, Fspec rate: 0
...