Configuring Bgp; Bgp Advantages - HP ProCurve Secure Router 7203 dl Advanced Management And Configuration Manual

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Configuring BGP

BGP is an external protocol: it allows different autonomous systems to
exchange routes. BGP is the protocol most ISPs use, and it was designed to
allow diverse, sometimes competitive organizations to communicate:
BGP can filter both the routes it receives and those that it sends according
to bit length, thereby minimizing the number of routes exchanged.
BGP uses policies to determine best routes rather than per-hop counts,
like RIP does, or link states, like OSPF does. Autonomous systems can set
their own policy.
BGP routers communicate only with manually configured neighbors.
You can configure different policies for route exchange with different
neighbors.
BGP runs in External BGP (eBGP), which is the protocol used to communicate
between two autonomous systems, and Internal BGP (iBGP), which is the
protocol that the AS uses to synchronize its own routing tables.
Do not confuse eBGP with EGP, a nearly obsolete protocol once used on the
Internet. Also, do no confuse iBGP with an IGP such as OSPF. ISPs use iBGP
to distribute BGP routes between routers within an AS. However, ISPs usually
still need to run an IGP to generate routes for traffic within the AS.
On the ProCurve Secure Router, eBGP is intended to allow a private network
to send and receive routes from remote sites through the Internet. The private
network itself will run an IGP such as RIP or OSPF.
The WAN router runs BGP to communicate with the connecting ISP router,
also called the ISP edge router. The ISP tunnels the routes advertised by the
local router through the Internet to the remote sites. Only ISP routers that
connect to routers at the private organization's remote sites can receive these
routes, which they then pass to the private routers. Routers internal to the ISP
run an internal routing protocol and do not receive the private routes.

BGP Advantages

BGP is not the only way to use your ISP to advertise routes or distribute private
routes through the Internet. You can also use static routing or RIP v2.
IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring BGP
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