1 Background
MPLS (Multi Protocol label switching) multi-protocol label switching, the first designed by Cisco, in order to solve the purpose of router forwarding efficiency. Because of early no hardware forwarding technology. It is to insert a tab between two and three heads, forward IP packet using a label on the router, compared to traditional routing forwarding, less See Layer 3 IP packet process, to reduce hardware costs, improving the forwarding efficiency.
2 MPLS operation of the process of
1, the MPLS region, each LSR first run routing protocols, a routing table is formed
2, and then run the LDP, after the LSR assigns a label to the routing table of each destination, these labels only local significance, and there is LIB library.
3, each followed by a LSR advertises its own label adjacent peers.
4, each LSR label (a label) according to the label (the label) of the received and sent self associate to form LFIB
5, is inserted into the tag will receive the FIB associated with the destination network.
Note: MPLS label only IGP routing points, BGP routing points is not the label, the IGP routes BGP next hop address to the tag data is transmitted.
3 steps configuring MPLS
1, enable CEF
2, label distribution protocol specifies the use of (optional)
3, MPLS LDP router-id lo0 (optional)
4, MPLS label range 200 299 (optional)
5, run the LDP
6, the MTU value (optional)
Basic commands:
ip cef
int s0/0
mpls ip // enable MPLS in the interface
Extended command:
rouer (config) #mpls label protocol ldp // specified hired LDP (International Standard)
rouer(config)#mpls ldp router-id lo0
rouer (config) #mpls label range specified range of the router to assign labels 200 299 // need to re-establish a TCP connection
int s1/1
mpls ldp discovery transport-address interface // do specify the IP transport-address with their own interface, the address is used to build and address of the neighbor neighbor relationship, you can also specify the use of other interfaces, each interface will use the default router-id's Interface IP do transport-address, to build neighbor relationships.
Query command :
show mpls interfaces // View MPLS-enabled interface
show mpls ldp neighbor // View LDP neighbor table
show mpls ldp bindings // table view LIB, LIB (TIB) TIB here is cisco own called, in fact, LIB
show mpls forwarding-table // Check the label forwarding LFIB (TFIB)
Note: LFIB table indicates the second column shows the POP tag label pop top only, untagged represents eject all tags
It will only show the optimal allocation of the next-hop router label
show mpls ip binding // you can see a direct route into the label and the label
show ip cef // Check the FIB
show ip cef 2.2.2.0 // FIB table a detailed view
show ip cef detail // View Details
show adjacency
show adjacency detail
show mpls ldp discovery detail // see transport-address
show mpls forwarding-talbe labels 304 detail
show mpls ldp parameters // view the configuration parameters of LDP
show tag-switching tdp neighbor originally used in the TDP command