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BigIron RX Series Configuration Guide
53-1002253-01
Configuring confederations
26
•
If BGP4 load sharing is disabled (maximum-paths 1), the device selects the path that came
from the neighbor with the lower router ID.
•
If BGP4 load sharing is enabled, the device load shares among the remaining paths. In this
case, the router ID is not used to select a path.
NOTE
Router ID comparison is disabled by default.
To enable router ID comparison, enter the following command at the BGP configuration level of the
CLI.
BigIron RX(config-bgp)# compare-routerid
Syntax: [no] compare-routerid
For more information, refer to
“How BGP4 selects a path for a route”
on page 740.
Configuring confederations
A
confederation
is a BGP4 Autonomous System (AS) that has been subdivided into multiple,
smaller ASs. Subdividing an AS into smaller ASs simplifies administration and reduces BGP-related
traffic, thus reducing the complexity of the Interior Border Gateway Protocol (IBGP) mesh among
the BGP routers in the AS.
The Brocade implementation of this feature is based on RFC 3065.
Normally, all BGP routers within an AS must be fully meshed, so that each BGP router has BGP
sessions to all the other BGP routers within the AS. This is feasible in smaller ASs but becomes
unmanageable in ASs containing many BGP routers.
When you configure BGP routers into a confederation, all the routers within a sub-AS (a subdivision
of the AS) use IBGP and must be fully meshed. However, routers use EBGP to communicate
between different sub-ASs.
NOTE
Another method for reducing the complexity of an IBGP mesh is to use route reflection. However, if
you want to run different Interior Gateway Protocols (IGPs) within an AS, configure a confederation.
You can run a separate IGP within each sub-AS.
To configure a confederation, configure groups of BGP routers into sub-ASs. A sub-AS is simply an
AS. The term “sub-AS” distinguishes ASs within a confederation from ASs that are not in a
confederation. For the viewpoint of remote ASs, the confederation ID is the AS ID. Remote ASs do
not know that the AS represents multiple sub-ASs with unique AS IDs.
NOTE
You can use any valid AS numbers for the sub-ASs. If your AS is connected to the Internet, Brocade
recommends that you use numbers from within the private AS range (64512 – 65535). These are
private ASs numbers and BGP4 routers do not propagate these AS numbers to the Internet.
Figure 114
shows an example of a BGP4 confederation.
Содержание BigIron RX Series
Страница 100: ...24 BigIron RX Series Configuration Guide 53 1002253 01 Logging on through the Web Management Interface 2 ...
Страница 192: ...116 BigIron RX Series Configuration Guide 53 1002253 01 Configuring authentication method lists 4 ...
Страница 228: ...152 BigIron RX Series Configuration Guide 53 1002253 01 Enabling WAN PHY mode support 6 ...
Страница 312: ...236 BigIron RX Series Configuration Guide 53 1002253 01 Displaying IP information 7 ...
Страница 356: ...280 BigIron RX Series Configuration Guide 53 1002253 01 Resetting LLDP statistics 9 ...
Страница 402: ...326 BigIron RX Series Configuration Guide 53 1002253 01 Transparent firewall mode 11 ...
Страница 432: ...356 BigIron RX Series Configuration Guide 53 1002253 01 SuperSpan 12 ...
Страница 500: ...424 BigIron RX Series Configuration Guide 53 1002253 01 MRP CLI example 14 ...
Страница 580: ...504 BigIron RX Series Configuration Guide 53 1002253 01 Configuring multicast traffic engineering 18 ...
Страница 591: ...BigIron RX Series Configuration Guide 515 53 1002253 01 Displaying traffic reduction 19 ...
Страница 592: ...516 BigIron RX Series Configuration Guide 53 1002253 01 Displaying traffic reduction 19 ...
Страница 598: ...522 BigIron RX Series Configuration Guide 53 1002253 01 Viewing Layer 2 ACLs 20 ...
Страница 656: ...580 BigIron RX Series Configuration Guide 53 1002253 01 Trunk formation 22 ...
Страница 754: ...678 BigIron RX Series Configuration Guide 53 1002253 01 Displaying RIP filters 24 ...
Страница 814: ...738 BigIron RX Series Configuration Guide 53 1002253 01 Displaying OSPF information 25 ...
Страница 932: ...856 BigIron RX Series Configuration Guide 53 1002253 01 Generalized TTL security mechanism support 26 ...
Страница 980: ...904 BigIron RX Series Configuration Guide 53 1002253 01 Clearing IS IS information 28 ...
Страница 1000: ...924 BigIron RX Series Configuration Guide 53 1002253 01 Using secure copy 30 ...
Страница 1088: ...1012 BigIron RX Series Configuration Guide 53 1002253 01 IP source guard 35 ...
Страница 1108: ...1032 BigIron RX Series Configuration Guide 53 1002253 01 Reading CDP packets 37 ...
Страница 1126: ...1050 BigIron RX Series Configuration Guide 53 1002253 01 Clearing sFlow statistics 39 ...
Страница 1140: ...1064 BigIron RX Series Configuration Guide 53 1002253 01 802 1s Multiple Spanning Tree Protocol 40 ...
Страница 1324: ...1248 BigIron RX Series Configuration Guide 53 1002253 01 Displaying OSPFv3 information 48 ...
Страница 1363: ...BigIron RX Series Configuration Guide 1287 53 1002253 01 Continuous System Monitor 51 ...
Страница 1364: ...1288 BigIron RX Series Configuration Guide 53 1002253 01 Continuous System Monitor 51 ...
Страница 1404: ...1328 BigIron RX Series Configuration Guide 53 1002253 01 Commands That Require a Reload D ...
Страница 1458: ...1382 BigIron RX Series Configuration Guide 53 1002253 01 VSRP E ...