Multihoming - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

Customer A
Network
10.1.1.0 /24
Figure 13-15. VFR
The ISP edge router connecting to the local site forms an MPLS Label Switch
Path (LSP) with the ISP edge router connecting to the authorized remote site.
(An LSP resembles a dynamic PVC.) The edge routers mark packets with an
MPLS label that directs them toward the other router through the LSP so that
only Customer A sites receive Customer A routes.

Multihoming

BGP is particularly useful when your router has more than one connection to
the Internet. These connections can be to the same provider or to two different
providers.
When you have only one Internet connection, static or RIP routing is some-
times a better choice. The lower overhead and simpler configuration outweigh
the loss in control. It does not matter that the router cannot balance loads
because all external traffic has the same destination.
However, in a network with two Internet connections, the router must decide
which connection to use for certain traffic. BGP allows a router to receive
different routes from the various ISPs to which it connects; it can then route
traffic accordingly. BGP also allows a router to advertise different networks
IP Routing—Configuring RIP, OSPF, BGP, and PBR
Routing table A
10.1.1.0 /24 1.1.1.2
Router A
1.1.1.2/30
Customer B
Configuring BGP
Routing table B
10.1.1.0 /24 2.2.2.2
ISP
2.2.2.2
Router B
Network
10.1.1.0 /24
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