LDP esstablishes a session in 2 steps; hello messages peridically sent on all MPLS-enabled interfaces MPLS enabled routers respond to received hello messages by attampting to esstablish a session with teh source of the hello message LDP link hello is UDP sent to “all routers on this subnet” …

RFC1771 – you have control only over your AS, you cannt tell other AS how to route traffic passing through (attributes). Neighbor relationship; Neighbors start in IDLE 1st Stage: ACTIVE 2nd Stage: OPEN SENT 3rd Stage: OPEN CONFIRMED 4th Stage: ESSTABLISHED Hello messages sent every 60 sec and …

BGP process in MPLS VPN; Global BGP routes (Internet routing) are exchanges as in traditional BGP setup VPNv4 Prefixes are exchanged through MP-BGP VPN routes are exchanged with CE routers through per-VRF External BGP sessions Configuring; (config)# router bgp (config-router)# address-family vpn4 …

VRF Configuration tasks; Create a VRF table Assign RD to the VRF Specify export and import route targets (optional) Configure a VPN ID Assign interfaces to VRFs Commands; (config)# ip vrf <name> (config-vrf)# rd route-distinguisher - can be 16 bit AS number: 32 bit decimal no OR 32 bit IP:16 …

Mandatory Enable CEF switching Configure LDP on every label-enabled interface Optional Configure MPLS ID Configure MTU size for labelled packets Configure IP TTL propagation Configure conditional label advertising Config mpls ldp router-id interface [force] router(config-if)# mpls ip …

IP aggregation/sumerisation breaks an LSP into 2 segments Aggregation should not be used where end-to-end LSP’s are required such as witin; MPLS VPNs MPLS TE MPLS enabled ATM network Transit BGP where core routers are not running BGP Label allocatation and distribution in a frame-mode MPLS network …

A label is removed on the router before the last hop within an MPLS domain. PHP optimises MPLS performance (one less LFIB lookup) PHP does not work on ATM (Virtual Path Identifiers/virtual channel identifies cannot be removed) The pop or implicit null label uses a reserved value when being …

OK, so having known about MPLS for a few years and actually get a provided service in my work environment as well as the fact it is on the CCIE R&S blueprint I thought I should get a much better understanding of how it works and the various terminology’s. My notes so far; The benifits of MPLS; …

Root Guard is a mechanism that allows the administrator to control where candidate root bridges can be connected to the network, it will basically prevent the wrong switch (say a random one just added) from becoming the root bridge. If a Rood guard port receives a BPDU that might cause the sender to …

The following tables is the CCIE R&S Blueprint, it is a combination of DOC-4375 and DOC-6864. [table id=15 /]