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Hi Alex,MP-BGP and LDP running smooth over GRE.Here and example of 2 PE routers (R4 and R5) have GRE tunnel established and up between each others, MP-BGP and LDP running over the tunnel.In the below example i did used loopback 400 and 500 on R4 and R5 as CE routers under VRF VPN-A, also the below MTU configurations for MPLS-VPN only if you gone use AToM or TE you need to increase the MTU (4 bytes per label)((R4))ip vrf VPN-A rd 188.8.131.52:1 route-target export 1:1 route-target import 1:1interface Loopback400 ip vrf forwarding VPN-A ip address 184.108.40.206 255.255.255.0interface Tunnel1 ip address 220.127.116.11 255.255.255.252 ip mtu 1524 mpls ip mpls mtu 1532 keepalive 10 3 tunnel source Serial1/0 tunnel destination 10.10.45.5Router bgp 1 no synchronization bgp log-neighbor-changes neighbor 18.104.22.168 remote-as 1 no auto-summary ! address-family vpnv4 neighbor 22.214.171.124 activate neighbor 126.96.36.199 send-community both exit-address-family ! address-family ipv4 vrf VPN-A redistribute connected redistribute static no synchronization exit-address-family((R5))ip vrf VPN-A rd 188.8.131.52:1 route-target export 1:1 route-target import 1:1interface Loopback500 ip vrf forwarding VPN-A ip address 10.1.1.5 255.255.255.0!interface Tunnel1 ip address 184.108.40.206 255.255.255.252 ip mtu 1524 mpls ip mpls mtu 1532 keepalive 10 3 tunnel source Serial0/0/0 tunnel destination 10.10.45.4router bgp 1 no synchronization bgp log-neighbor-changes neighbor 220.127.116.11 remote-as 1 no auto-summary ! address-family vpnv4 neighbor 18.104.22.168 activate neighbor 22.214.171.124 send-community both exit-address-family ! address-family ipv4 vrf VPN-A redistribute connected redistribute static no auto-summary no synchronization exit-address-familyR5#show ip route vrf VPN-A bgp 126.96.36.199/24 is subnetted, 1 subnetsB 188.8.131.52 [200/0] via 184.108.40.206, 00:06:34R5#ping vrf VPN-A 220.127.116.11Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 18.104.22.168, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 72/72/76 msR5#ping vrf VPN-AProtocol [ip]: Target IP address: 22.214.171.124Repeat count : Datagram size : 1508Timeout in seconds : Extended commands [n]: ySource address or interface: Type of service : Set DF bit in IP header? [no]: yesValidate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: Sweep range of sizes [n]: Type escape sequence to abort.Sending 5, 1508-byte ICMP Echos to 126.96.36.199, timeout is 2 seconds:Packet sent with the DF bit set!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 776/776/776 msR5#show ip bg vp al summary BGP router identifier 188.8.131.52, local AS number 1BGP table version is 5, main routing table version 53 network entries using 411 bytes of memory3 path entries using 204 bytes of memory3/2 BGP path/bestpath attribute entries using 372 bytes of memory1 BGP extended community entries using 24 bytes of memory0 BGP route-map cache entries using 0 bytes of memory0 BGP filter-list cache entries using 0 bytes of memoryBGP using 1011 total bytes of memoryBGP activity 3/0 prefixes, 3/0 paths, scan interval 15 secsNeighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd184.108.40.206 4 1 30 30 5 0 0 00:13:16 1Bes Regards,Mounir Mohamed
HI Mounir,The Configuration you POSTED is really useful.I have some Questions:======================What is the difference between the MP-BGP and BGP ?Do you have a "Sample Template" for a MP-BGP Configuration between PE-PE ?In the above Configuration, there is a Tunnel between the PE-PE to form MP-BGP Mesh. In this case, if i have 10" PE's for example, so i should run Tunnel between each other to complete the MP-BGP Mesh ?Thanks in Advance.Best Regards,Guru Prasad R
Hi Guru,BGP Originally designed to carry routing information only for IPv4 address family,But actually this was limitation for BGP, because there is so many protocols need to be carry also, so IETF standardized the Multiprotocol extensions for BGP, this extension allow BGP4 to carry routing Information for multiple network layer protocols like (IPv6, IPX, and VPNv4)Regarding the MP-BGP configurations of PE-to-PE this is not the common case, usually MP-BGP Route-Reflector used to save resources and overhead.Please rate helpful posts.Best Regards,Mounir Mohamed