25.02.2013 Views

TCP/IP Tutorial and Technical Overview - IBM Redbooks

TCP/IP Tutorial and Technical Overview - IBM Redbooks

TCP/IP Tutorial and Technical Overview - IBM Redbooks

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

5.9.1 BGP concepts <strong>and</strong> terminology<br />

BGP uses specific terminology to describe the operation of the protocol.<br />

Figure 5-21 illustrates this terminology.<br />

OSPF/R<strong>IP</strong><br />

OSPF/R<strong>IP</strong><br />

OSPF/R<strong>IP</strong><br />

OSPF/R<strong>IP</strong><br />

BGP Speaker<br />

Figure 5-21 Components of a BGP network<br />

BGP uses the following terms:<br />

► BGP speaker: A router configured to support BGP.<br />

► BGP neighbors (peers): A pair of BGP speakers that exchange routing<br />

information. There are two types of BGP neighbors:<br />

– Internal (IBGP) neighbor: A pair of BGP speakers within the same AS.<br />

– External (EBGP) neighbor: A pair of BGP neighbors, each in a different<br />

AS. These neighbors typically share a directly connected network.<br />

► BGP session: A <strong>TCP</strong> session connecting two BGP neighbors. The session is<br />

used to exchange routing information. The neighbors monitor the state of the<br />

session by sending keepalive messages. 1<br />

216 <strong>TCP</strong>/<strong>IP</strong> <strong>Tutorial</strong> <strong>and</strong> <strong>Technical</strong> <strong>Overview</strong><br />

EBGP<br />

AS1 AS2<br />

IBGP<br />

OSPF/R<strong>IP</strong><br />

BGP Speaker<br />

OSPF/R<strong>IP</strong><br />

BGP Speaker<br />

OSPF/R<strong>IP</strong><br />

BGP Speaker<br />

AS3<br />

OSPF/R<strong>IP</strong><br />

BGP Speaker<br />

EBGP<br />

OSPF/R<strong>IP</strong><br />

OSPF/R<strong>IP</strong><br />

IBGP<br />

OSPF/R<strong>IP</strong><br />

EBGP<br />

ASX

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!