BigIron RX Series Configuration Guide
761
53-1001810-01
Configuring confederations
26
Figure 114
shows an example of a BGP4 confederation.
FIGURE 114
Example BGP4 confederation
In this example, four routers are configured into two sub-ASs, each containing two of the routers.
The sub-ASs are members of confederation 10. Routers within a sub-AS must be fully meshed and
communicate using IBGP. In this example, routers A and B use IBGP to communicate. Routers C
and D also use IBGP. However, the sub-ASs communicate with one another using EBGP. For
example, router A communicates with router C using EBGP. The routers in the confederation
communicate with other ASs using EBGP.
Routers in other ASs are unaware that routers A – D are configured in a confederation. In fact,
when routers in confederation 10 send traffic to routers in other ASs, the confederation ID is the
same as the AS number for the routers in the confederation. Thus, routers in other ASs see traffic
from AS 10 and are unaware that the routers in AS 10 are subdivided into sub-ASs within a
confederation.
Configuring a BGP confederation
Perform the following configuration tasks on each BGP router within the confederation:
•
Configure the local AS number. The local AS number indicates membership in a sub-AS. All
BGP routers with the same local AS number are members of the same sub-AS. BGP routers
use the local AS number when communicating with other BGP routers within the
confederation.
•
Configure the confederation ID. The confederation ID is the AS number by which BGP routers
outside the confederation know the confederation. Thus, a BGP router outside the
confederation is not aware and does not care that your BGP routers are in multiple sub-ASs.
BGP routers use the confederation ID when communicating with routers outside the
confederation. The confederation ID must be different from the sub-AS numbers.
Router A
Router B
Router C
Router D
IBGP
IBGP
EBGP
Sub-AS 64513
Sub-AS 64512
EBGP
Confederation 10
AS 20
This BGP4 router sees all
traffic from Confederation 10
as traffic from AS 10.
Routers outside the confederation
do not know or care that the routers
are subdivided into sub-ASs within a
confederation.
Summary of Contents for Brocade DCX
Page 40: ...xl BigIron RX Series Configuration Guide 53 1001810 01 ...
Page 72: ...lxxii BigIron RX Series Configuration Guide 53 1001810 01 ...
Page 88: ...16 BigIron RX Series Configuration Guide 53 1001810 01 Searching and filtering output 1 ...
Page 300: ...228 BigIron RX Series Configuration Guide 53 1001810 01 Displaying IP information 7 ...
Page 318: ...246 BigIron RX Series Configuration Guide 53 1001810 01 Deploying a LAG 8 ...
Page 418: ...346 BigIron RX Series Configuration Guide 53 1001810 01 SuperSpan 12 ...
Page 482: ...410 BigIron RX Series Configuration Guide 53 1001810 01 MRP CLI example 14 ...
Page 506: ...434 BigIron RX Series Configuration Guide 53 1001810 01 Displaying VSRP information 15 ...
Page 582: ...510 BigIron RX Series Configuration Guide 53 1001810 01 Viewing Layer 2 ACLs 20 ...
Page 634: ...562 BigIron RX Series Configuration Guide 53 1001810 01 Troubleshooting ACLs 21 ...
Page 642: ...570 BigIron RX Series Configuration Guide 53 1001810 01 Trunk formation 22 ...
Page 746: ...674 BigIron RX Series Configuration Guide 53 1001810 01 Displaying RIP filters 24 ...
Page 808: ...736 BigIron RX Series Configuration Guide 53 1001810 01 Displaying OSPF information 25 ...
Page 938: ...866 BigIron RX Series Configuration Guide 53 1001810 01 Displaying MBGP information 27 ...
Page 950: ...878 BigIron RX Series Configuration Guide 53 1001810 01 Using secure copy 28 ...
Page 988: ...916 BigIron RX Series Configuration Guide 53 1001810 01 Clearing IS IS information 29 ...
Page 1054: ...982 BigIron RX Series Configuration Guide 53 1001810 01 Sample 802 1x configurations 33 ...
Page 1108: ...1036 BigIron RX Series Configuration Guide 53 1001810 01 sFlow 39 ...
Page 1190: ...1118 BigIron RX Series Configuration Guide 53 1001810 01 Displaying RIPng information 44 ...
Page 1270: ...1198 BigIron RX Series Configuration Guide 53 1001810 01 Displaying ACLs 47 ...
Page 1310: ...1238 BigIron RX Series Configuration Guide 53 1001810 01 Displaying OSPFv3 information 48 ...
Page 1382: ...1310 BigIron RX Series Configuration Guide 53 1001810 01 Commands That Require a Reload D ...
Page 1435: ...BigIron RX Series Configuration Guide 1363 53 1001810 01 VSRP E ...
Page 1436: ...1364 BigIron RX Series Configuration Guide 53 1001810 01 VSRP E ...