What is MPLS (Multi-Protocol Label Switching) ? MPLS is lable base fast switching, MPLS is a technique which forward the packets in network on bases of labels. Why MPLS? Router use the process switching in which whenever router received a packet it checks its IP address match with routing table and forward packet, send ARP request for MAC addres. This Process become a little slow when router dealing with a lot of IP packets, in case of VOIP e.g. a IP-Phone call may using 50packets/second then router have to perform process switching for every packets But in MPLS instead of processing above large packet each time route just use a label to forward a packet which saving some processing cycle and made fast forwarding. MPLS Configuration on GNS3: Design above lab in gns3 and configure IP address and EIGRP according to EIGRP configuration on GNS3 . In our lab R3 is provider router where as R2, R4 and R5 are the provider edge routers. On Cisco router to enable the MPLS you required to : Enable CEF(cisco express forwarding) on router Change MTU (maximum transmission unit) from 1500 to 1512 on MPLS enabled interfaces, becase MPLS header is of 4 bytes and one interface have maximum of three. R2 MPLS configuration Commmands: R2#conf t R2(config)#ip cef R2(config)#int s1/1 R2(config-if)#mpls label protocol ldp R2(config-if)# mpls ip R2(config-if)# mpls mtu 1512 R2(config-if)#ip route-cache cef R3 MPLS configuration Commmands: R3(config)#ip cef R3(config)#int s1/1 R3(config-if)#ip route-cache cef R3(config-if)#mpls mtu 1512 R3(config-if)#mpls ip R3(config-if)#mpls label protocol ldp R3(config-if)#int s1/2 R3(config-if)#mpls mtu 1512 R3(config-if)#ip route-cache cef R3(config-if)#mpls ip R3(config-if)#mpls label protocol ldpR3(config)#int s1/0 R3(config-if)#mpls mtu 1512 R3(config-if)#ip route-cache cef R3(config-if)#mpls ip R3(config-if)#mpls label protocol ldp R4 MPLS configuration Commmands: R4(config)#ip cef R4(config)#int s1/0 R4(config-if)# mpls ip R4(config-if)#mpls label protocol ldp R4(config-if)# mpls mtu 1512 R5 MPLS configuration Commmands: R5(config)#ip cef R5(config)#int s1/0 R5(config-if)# mpls label protocol ldp R5(config-if)# mpls ip R5(config-if)# mpls mtu 1512 R5(config-if)# R5(config-if)#ip route-cache cef MPLS Verification Commands: R3#show mpls ldp neighbor R3#show mpls forwarding-table R3#show ip cef R3#sh mpls ip binding R3#sh mpls forwarding-table interface serial 1/1 Learn About OSPF, IS IS and EIGRP. Download MPLS Books:
