MPLS

Label Distribution Protocol

Note

VyOS’ MPLS support is not finished yet, its funcitionality is limited. Currently it can only be configured as a P router, that is, an LSR in the core of an MPLS network.

The Multi-Protocol Label Switching (MPLS) architecture does not assume a single protocol to create MPLS paths. VyOS supports the Label Distribution Protocol (LDP) as implemented by FRR, based on RFC 5036.

LDT it is an MPLS signaling protocol that distributes labels creating MPLS paths in a dynamic manner. LDT is not exactly a routing protocol, as it relies on other routing protocols for forwarding decisions.

set protocols mpls ldp interface <interface>
Use this command to enable LDP in the interface you define.
set protocols mpls ldp router-id <address>
Use this command to configure the IP address used as the LDP router-id of the local device

In order to allow the exchange of label advertisements required for LDP, a TCP session should be established between routers. Routers will need to learn each other’s transport address in order to establish the TCP session.

You may want to use the same address for both the LDP router-id and the discovery transport address, but for VyOS MPLS LDP to work both parameters must be explicitely set in the configuration.

set protocols mpls ldp discovery transport-ipv4-address | transport-ipv6-address <address>
Use this command to set the IPv4 or IPv6 transport-address used by LDP.
set protocols mpls ldp neighbor <address> password <password>
Use this command to configure authentication for LDP peers. Set the IP address of the LDP peer and a password that should be shared in order to become neighbors.

Example

set interfaces dummy dum0 address '2.2.2.2/32'
set interfaces ethernet eth1 address '10.0.0.2/24'
set interfaces ethernet eth2 address '10.0.255.1/24'
set protocols mpls ldp discovery transport-ipv4-address '2.2.2.2'
set protocols mpls ldp interface 'eth1'
set protocols mpls ldp interface 'eth2'
set protocols mpls ldp router-id '2.2.2.2'
set protocols ospf area 0 network '0.0.0.0/0'
set protocols ospf parameters router-id '2.2.2.2'

show commands

When LDP is working, you will be able to see label information in the outcome of show ip route. Besides that information, there are also specific show commands for LDP:

show mpls ldp binding
Use this command to see the Label Information Base.
show mpls ldp discovery
Use this command to see Discovery Hello information
show mpls ldp interface
Use this command to see LDP interface information
show mpls ldp neighbor
Uset this command to see LDP neighbor information
show mpls ldp neighbor detail
Uset this command to see detailed LDP neighbor information