HPE FlexFabric 5950 Series User Manual

17
2BConfiguring LDP
31B
Overview
The Label Distribution Protocol (LDP) dynamically distributes FEC-label mapping information
between LSRs to establish LSPs.
146BTerminology
325BLDP session
Two LSRs establish a TCP-based LDP session to exchange FEC-label mappings.
326BLDP peer
Two LSRs that use LDP to exchange FEC-label mappings are LSR peers.
327BLabel spaces and LDP identifiers
Label spaces include the following types:
• Per-interface label space—Each interface uses a single, independent label space. Different
interfaces can use the same label values.
• Per-platform label space—Each LSR uses a single label space. The device only supports the
per-platform label space.
A six-byte LDP Identifier (LDP ID) identifies a label space on an LSR. It is in the format of <LSR
ID>:<label space number>, where:
• The LSR ID takes four bytes to identity the LSR.
• The label space number takes two bytes to identify a label space within the LSR.
A label space number of 0 indicates that the label space is a per-platform label space. A label space
number other than 0 indicates a per-interface label space.
LDP uses the same LDP ID format on IPv4 and IPv6 networks. An LDP ID must be globally unique.
328BFECs and FEC-label mappings
MPLS groups packets with the same characteristics (such as the same destination or service class)
into a class, called an FEC. The packets of the same FEC are handled in the same way on an MPLS
network.
LDP can classify FECs by destination IP address.
An LSR assigns a label for an FEC and advertises the FEC-label mapping, or FEC-label binding, to
its peers in a Label Mapping message.
147BLDP messages
LDP mainly uses the following types of messages:
• Discovery messages—Declare and maintain the presence of LSRs, such as Hello messages.
• Session messages—Establish, maintain, and terminate sessions between LDP peers, such
as Initialization messages used for parameter negotiation and Keepalive messages used to
maintain sessions.
• Advertisement messages—Create, alter, and remove FEC-label mappings, such as Label
Mapping messages used to advertise FEC-label mappings.

HPE FlexFabric 5950 Series Specifications

General

Brand	HPE
Model	FlexFabric 5950 Series
Category	Switch
Language	English