Bgp/Mpls Vpn Concepts - H3C S3610-28P Operation Manual

Operation Manual – MCE
H3C S3610&S5510 Series Ethernet Switches
Figure 1-1 A BGP/MPLS VPN implementation
CEs and PEs mark the boundary between the service providers and the customers.
A CE is usually a router. After a CE establishes adjacency with a directly connected PE,
it redistributes its VPN routes to the PE and learns remote VPN routes from the PE. A
CE and a PE use BGP/IGP to exchange routing information. You can also configure
static routes between them.
After a PE learns the VPN routing information of a CE, it uses BGP to exchange VPN
routing information with other PEs. A PE maintains routing information about only VPNs
that are directly connected, rather than all VPN routing information on the provider
network.
A P router maintains only routes to PEs. It does not need to know anything about VPN
routing information.
When VPN traffic travels over the MPLS backbone, the ingress PE functions as the
ingress LSR, the egress PE functions as the egress LSR, while P routers function as
the transit LSRs.
You can use H3C S3610&S5510 series switches as the CEs in a BGP/MPLS VPN
implementation.

1.1.2 BGP/MPLS VPN Concepts

I. Site
Site is often mentioned in the VPN, whose meanings are described as follows:
A site is a group of IP systems with IP connectivity that does not rely on any
service provider network to implement.
The classification of a site depends on the topology relationship of the devices,
rather than the geographical positions, though the devices at a site are adjacent to
each other geographically in most cases.
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Chapter 1 MCE Overview