When configuring BGP, remember that BGP
supports two types of sessions, each with slightly different
configuration requirements:
- EBGP session - Occurs
between routers in two different autonomous systems. These
routers are usually adjacent to one another, sharing the same
medium and a subnet (see RTA in the figure).
- IBGP session - Occurs
between routers in the same AS, and is used to coordinate and
synchronize routing policy within the AS. Neighbors may be
located anywhere in the AS, even several hops away from one
another. An IBGP session typically occurs between routers in the
same AS in an ISP (see RTC in the figure).
If the AS-number
configured in the
router bgp command is identical to the
AS-number
configured in the
neighbor statement, BGP will initiate an internal session. If the
field values are different, BGP will build an external session.
 |
 |
Interactive
Lab Activity
(Flash,
367 kB) |
| |
In
this lab, you will configure the SanJose3 router
for BGP and verify its operation using show
commands. All routers have been already
configured for IP. The ISP routers are running
BGP. |
|
|
|
|