(Optional) Configuring Tunnel Constraints

Context

Constraints such as bandwidth and explicit path attributes can be configured on the ingress to accurately and flexibly establish an RSVP-TE tunnel.

Perform the following configurations on the ingress node of an MPLS TE tunnel.

Configuring an MPLS TE Explicit Path

You need to configure an explicit path before you can configure constraints on the explicit path.

An explicit path refers to a vector path on which a series of nodes are arranged in configuration sequence. The IP address of an interface on the egress is usually used as the destination address of the explicit path. Links or nodes can be specified for an explicit path so that a CR-LSP can be established over the specified path, facilitating resource allocation and efficiently controlling CR-LSP establishment.

Two adjacent nodes are connected in either of the following modes on an explicit path:
- Strict: Two consecutive hops must be directly connected. This mode strictly controls the path through which the LSP passes.
- Loose: Other nodes may exist between a hop and its next hop.
The strict and loose modes are used either separately or together.
Configuring Tunnel Constraints

After constraints are configured for tunnel establishment, a CR-LSP is established over a path calculated by CSPF.

Procedure

Configure an MPLS TE explicit path.
1. Run system-view
  The system view is displayed.
2. Run explicit-path path-name
  An explicit path is created and the explicit path view is displayed.
3. Run next hop ip-address [ include [ [ loose | strict ] | [ incoming | outgoing ] ] ^* | exclude ]
  A next-hop address is specified for the explicit path.
  
  By default, the include strict parameter is configured, meaning that a hop and its next hop must be directly connected. An explicit path can be configured to pass through a specified node or not to pass through a specified node.
  Either of the following parameters can be configured:
  - incoming: sets the ip-address to the IP address of an inbound interface of a next-hop node.
  - outgoing: sets the ip-address to the IP address of an outbound interface of a next-hop node.
4. You can run the following commands to add, modify, or delete nodes on the explicit path.
  - Run list hop [ ip-address ]
    
    Information about nodes on the explicit path is displayed.
  - Run add hop ip-address1 [ include [ [ loose | strict ] | [ incoming | outgoing ] ] ^* | exclude ] { after | before } ip-address2
    
    A node is added to the explicit path.
    
    By default, the include strict parameter is configured, meaning that a hop and its next hop must be directly connected. An explicit path can be configured to pass through a specified node or not to pass through a specified node.
    Either of the following parameters can be configured:
    - incoming: sets the ip-address1 to the IP address of an inbound interface of a new-added node.
    - outgoing: sets the ip-address1 to the IP address of an outbound interface of a new-added node.
  - Run modify hop ip-address1 ip-address2 [ include [ [ loose | strict ] | [ incoming | outgoing ] ] ^* | exclude ]
    
    The address of a node is changed to allow another specified node to be used by the explicit path.
    
    By default, the include strict parameter is configured, meaning that a hop and its next hop must be directly connected. An explicit path can be configured to pass through a specified node or not to pass through a specified node.
    Either of the following parameters can be configured:
    - incoming: sets the ip-address2 to the IP address of an inbound interface of the modified node.
    - outgoing: sets the ip-address2 to the IP address of an outbound interface of the modified node.
  - Run delete hop ip-address
    
    A node is deleted from the explicit path.
Configure tunnel constraints.
1. Run system-view
  The system view is displayed.
2. Run interface tunnel tunnel-number
  The tunnel interface view is displayed.
3. Run mpls te bandwidth { ct0 ct0-bw-value | ct1 ct1-bw-value }
  The bandwidth is configured for the tunnel.
  
  The bandwidth used by the tunnel cannot be greater than the maximum reservable link bandwidth.
  
  Ignore this step if only an explicit path is required.
  
  The configured bandwidth takes effect only during tunnel establishment and protocol negotiation, and does not limit the bandwidth for traffic forwarding. (S5720-HI does not have this restriction.)
4. Run mpls te path explicit-path path-name
  An explicit path is configured for the tunnel.
  
  Ignore this step if only the bandwidth needs to be specified.
5. Run mpls te commit
  The configuration is committed.