Information Technology Reference
In-Depth Information
Figure 8-3
Confederation-Based Topology
AS 200
R8
172.16.0.0/16
AS 65000
AS 65001
R1
R4
R6
192.168.200.0/24
192.168.201.0/24
192.168.202.0/24
R3
R2
R7
R5
Confederation 100
To simplify the addressing scheme, all the addresses within AS 100 are in the range of
192.168.0.0/16, and all link addresses are of /24 length. Router numbers are used as the
corresponding link addresses (the third octet) and host addresses (the fourth octet). For
example, the link between R1 and R2 has the address 192.168
.12.
0/24, with R1's and
R2's addresses as 192.168
.12.1
and 192.168
.12.2
, respectively. As another example, the
addresses of R4 and R7 for the link between them are 192.168
.47.4
and 192.168
.47.7
,
respectively. Loopback addresses are in the range of 192.168.100.0/24, with the router ID
as the host part of the addresses. For example, the loopback 0 interface address on R1 is
192.168.100
.1
/32. The loopback 0 address is used as the BGP router ID for that router.
All link addresses and loopback addresses are part of the IGP, which is IS-IS, in AS 100. A
single level, Level 2, is used for this chapter. The loopback address for each router is used
as its system ID.
To simulate external prefix advertisements, prefix 172.16.0.0/16 is advertised from AS 200
to AS 100. The prefix 192.168.200.0/24 is injected into BGP in R3 to simulate a customer
route. Additionally, 192.168.201.0/24 and 192.168.202.0/24 are injected on R6 and R7,
respectively.
