mpls: basic LDP configuration

Basic configuration to act as a P router in an MPLS network.

docs/routing/index.rst

@@ -8,13 +8,20 @@ Routing
    :maxdepth: 1
 
    arp
+   bfd
    bgp
+   mpls
+   mss-clamp
+   multicast
+   routing-policy
+   static
+   rip
    rpki
    ospf
    pbr
-   rip
+   
-   static
+   
-   bfd
+   
-   mss-clamp
+   
-   routing-policy
+
-   multicast
+   

docs/routing/mpls.rst

@@ -0,0 +1,107 @@
+.. _mpls:
+
+****
+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 <https://tools.ietf.org/html/rfc5036.html>`__.
+
+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.
+
+
+.. cfgcmd:: set protocols mpls ldp interface <interface>
+
+   Use this command to enable LDP in the interface you define.
+
+
+.. cfgcmd:: 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.
+
+
+.. cfgcmd:: 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.
+
+.. cfgcmd:: 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
+-------
+
+.. code-block:: none
+
+   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: 
+
+
+.. opcmd:: show mpls ldp binding
+
+   Use this command to see the Label Information Base.
+
+
+.. opcmd:: show mpls ldp discovery
+
+   Use this command to see Discovery Hello information
+
+
+.. opcmd:: show mpls ldp interface
+
+   Use this command to see LDP interface information
+
+
+.. opcmd:: show mpls ldp neighbor
+
+   Uset this command to see LDP neighbor information
+
+
+.. opcmd:: show mpls ldp neighbor detail
+
+   Uset this command to see detailed LDP neighbor information
+
+