This section explains the four major functions of LDP in more detail.
LSRs that are running LDP send LDP Hello messages on all links that are LDP enabled. These are all the interfaces with mpls ip configured on them. First, however, you must enable CEF with the global ip cef command. Then you must enable LDP globally with the mpls ip command. Example 4-1 shows you the basic global and interface commands to enable LDP.
! hostname london ! ip cef ! mpls ldp router-id Loopback0 force mpls label protocol ldp ! interface Loopback0 ip address 10.200.254.2 255.255.255.255 ! interface Ethernet0/1/3 ip address 10.200.210.2 255.255.255.0 mpls ip !