BigIron RX Series Configuration Guide
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Aggregating routes advertised to BGP4 neighbors
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Aggregating routes advertised to BGP4 neighbors
By default, the device advertises individual routes for all the networks. The aggregation feature
allows you to configure the device to aggregate routes in a range of networks into a single network
prefix. For example, without aggregation, the device will individually advertise routes for networks
207.95.1.0/24, 207.95.2.0/24, and 207.95.3.0/24. You can configure the device to instead send a
single, aggregate route for the networks. The aggregate route can be advertised as 207.95.0.0/16.
To aggregate routes for 209.157.22.0/24, 209.157.23.0/24, and 209.157.24.0/24, enter the
following command.
BigIron RX(config-bgp)# aggregate-address 209.157.0.0 255.255.0.0
Syntax: aggregate-address
<ip-addr>
<ip-mask>
[as-set] [summary-only] [suppress-map
<map-name>
] [advertise-map
<map-name>
] [attribute-map
<map-name>
]
The
<ip-addr>
and
<ip-mask>
parameters specify the aggregate value for the networks. Specify 0
for the host portion and for the network portion that differs among the networks in the aggregate.
For example, to aggregate 10.0.1.0/24, 10.0.2.0/24, and 10.0.3.0/24, enter the IP address
10.0.0.0 and the network mask 255.255.0.0.
The as-set parameter causes the router to aggregate AS-path information for all the routes in the
aggregate address into a single AS-path.
The summary-only parameter prevents the router from advertising more specific routes contained
within the aggregate route.
The suppress-map
<map-name>
parameter prevents the more specific routes contained in the
specified route map from being advertised.
The advertise-map
<map-name>
parameter configures the router to advertise the more specific
routes in the specified route map.
The attribute-map
<map-name>
parameter configures the router to set attributes for the aggregate
routes based on the specified route map.
NOTE
For the suppress-map, advertise-map, and attribute-map parameters, the route map must already
be defined. Refer to “
“Defining route maps”
on page 798 for information on defining a route map.
Configuring the BigIron RX to always compare Multi-Exit
Discriminators (MEDs)
A Multi-Exit Discriminator (MED) is a value that the BGP4 algorithm uses when comparing multiple
paths received from different BGP4 neighbors in the same AS for the same route. In BGP4, a
route’s MED is equivalent to its “metric”.
BGP4 compares the MEDs of two otherwise equivalent paths
if and only if
the routes were learned
from the same neighboring AS. This behavior is called deterministic MED. Deterministic MED is
always enabled and cannot be disabled.
In addition, you can enable the device to always compare the MEDs, regardless of the AS
information in the paths. To enable this comparison, enter the always-compare-med command at
the BGP4 configuration level of the CLI. This option is disabled by default.
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 ...