Brocade Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide (Supporting R05.6.00) - Manual (Page 641)

Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide 617
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BGP or MPLS VPN components and what they do
6
BGP
RFC 1771 – A Border Gateway Protocol 4 (BGP-4)
RFC 1997 – BGP Communities Attribute
RFC 2283 – Multiprotocol Extensions for BGP-4
RFC 2842 – Capabilities Advertisement with BGP-4
RFC 2858 – Multiprotocol Extensions for BGP-4
RFC 3107 – Carrying Label Information in BGP-4
Draft standards
draft-ietf-idr-route-filter-11
draft-ietf-idr-bgp-ext-communities-07
MIB support
RFC 4382 – MPLS or BGP Layer 3 Virtual Private Network (VPN) Management Information Base
(with full support introduced in version 03.2.00 of the Multi-Service IronWare software).
BGP or MPLS VPN components and what they do
This section describes each of the following components, which make up a BGP or MPLS VPN (refer
to
Figure 70 ):
• Customer Edge device (CE)
• Provider Edge device (PE)
• Virtual Routing and Forwarding table (VRF)
• Provider MPLS domain
The Customer Edge device (CE) – The CE provides connectivity with a customer’s network and a
Provider Edge device (PE). It can advertise routes available from the customer’s network using RIP,
OSPF or EBGP. Alternately, the CE can create a static default route to a PE. Outbound packets from
a customer’s network are forwarded from the CE to the PE, and inbound packets are forwarded
from the PE to the CE attached to the customer’s network.
The Provider Edge device (PE) – In a BGP or MPLS VPN, the central component is the PE. The PE
provides connectivity with the CE and with the MPLS domain. On one side of the PE, routing
information is exchanged with the CE using either static routes, RIP, OSPF, or EBGP. On the other
side, IBGP is used with BGP multiprotocol extensions to communicate with all of the other PEs that
are connected to networks in the same VPN and available to the customer’s network. When a CE
sends packets to a PE to forward across an MPLS domain, that PE functions as an MPLS ingress
Label Edge device (LER) and the PE on the other end of the domain functions as an MPLS egress
LER.
Virtual Routing and Forwarding table (VRF) – The PE maintains a Virtual Routing and Forwarding
table (VRF) for each customer that is attached to it through a CE. The VRF contains routes between
the PE and the CE and Label Switched Paths (LSPs) across the MPLS domain for each PE that is a
member of the customer’s VPN. VRFs are defined on interfaces of the PEs.