Zte ZXR10 GER, Руководство пользователя

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Chapter 20 MPLS VPN Configuration
Confidential and Proprietary Information of ZTE CORPORATION 289
Related Terms
A BGP/MPLS VPN network system covers the following types of
network equipment.
A PE refers to a router connected to a CE in a client site on a
carrier’s network. A PE router supports VPN and labeling function
(the labeling function can be provided by RSVP, LDP or CR-LDP).
In a single VPN, a tunnel is used for connecting two PE routers,
and the tunnel can be an MPLS LSP tunnel or an LDP tunnel.
Here, “P” refers a router in the core of a carrier’s network, which
is not connected to any router in any customer site, but is a part
of the tunnel in a PE pair. “P” supports MPLS LSP or LDP, but
does not need to support VPN.
CE refers to a router or switch connected to a carrier’s network
in a customer site. Normally, CE refers to an IP router.
VPN function is provided by a PE router, while P and CE routers
do not have other VPN configuration requirements.
VPN-IPv4 Address and Route
Distinguisher (RD)
L3 VPN may be connected to private networks via the Internet;
these private networks can use public addresses or private
addresses. When private networks use private addresses,
addresses between different private networks may be repeated.
To avoid repetition of private addresses, public addresses can be
used in network equipment to replace private addresses. A
solution is provided in RFC2547bis, which uses an existing
private network ID to generate a definite new address.
New address is a part of VPN-IPv4 address cluster and is a BGP
address cluster of the MP-BGP protocol. In a VPN-IPv4 address,
there is a value used to differentiate different VPNs, called Route
Distinguisher (RD).
Format of a VPN-IPv4 address is an eight-byte Router
Distinguisher (RD) plus a four-byte IP address. RD is the eight-
byte value used for VPN differentiation. An RD consists of the
following domains:
„
Type domain (two bytes): Determines the length of the other
domains
If value of the type domain is 0, administrator (ADM) domain
is four bytes and the Assignment Number (AN) domain is two
bytes.
If value of the type domain is 1, administrator (ADM) domain
is two bytes and the Assignment Number (AN) domain is four
bytes.
PE (Provider
Edge)
P (Provider)
CE (Customer
Edge)
L3 VPN
RFC 2547bis
RD Definition