Riverstone Networks RS Switch Router User Guide Release 8.0 17-27
MPLS Configuration Configuring L3 Label Switched Paths
17.5 CONFIGURING L3 LABEL SWITCHED PATHS
The RS supports two basic types of LSPs:
•Static LSPs require that you configure all routers and assign all labels in the path. This is similar to
configuring static routes on the router, and there is no reporting of errors or statistics. MPLS must
be enabled. No signaling protocol is used, so yo u do not need to enable RSVP or LDP.
•Dynamic LSPs (also called signaled LSPs) use RSVP to set up the path and dynamically assign
labels. On the ingress LSR, you configure the LSP as well as enable MPLS and RSVP. On all other
LSRs in the dynamic LSP, you only need to enable MPLS and RSVP.
17.5.1 Configuring L3 Static LSPs
In a static LSP, each router in the path must be configured with static forwarding information. You can specify label
values between 16 and 1024. No signaling protocol is used. MPLS must be enabled on all routers, as described in
Section 17.2, "Enabling and Starting MPLS on the RS."
This section describes how to configure the ingress, transit, and PHP LSRs for a static LSP. (For a detailed example of
how to configure a static path on an RS router, see Section, "L3 Static Path Configuration Example.")
Ingress LSR Configuration
Use the mpls create static-path and mpls set static-path commands to configure a static LSP on the
ingress RS. When configuring the static LSP on the ingress LSR, you specify:
•destination IP address for the static path
•label value (between 16-1024) to be pushed onto the top of the label stack
•next-hop IP address (gateway) for the path
For example, the following command creates the static path SP1 on the ingress LSR. Packets to the destination 50.1.1.1
are assigned the label value 50 and are sent out on the next-hop 10.1.1.5.
Transit LSR Configuration
In a static LSP, transit LSRs can change (swap) the label value at the top of the label stack. Use the mpls set
interface command to configure the static LSP on the transit RS. When configuring the static LSP on the transit
LSR, you specify:
•the incoming interface or IP address for the path
•the next-hop interface or IP address for the path
•the incoming label value and one of the following actions to be taken on the label (the label map):
-swap the incoming label with a specified outgoing label value
-pop the top value on the label stack
-push a new label value on the top of the label stack
mpls create static-path SP1 to 50.1.1.1 push 50 gateway 10.1.1.5