User's Manual

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ip prefix-list abc deny 0.0.0.0/0 ge 25
This example: denies routes from network 10/8, because if the mask on class A network 10.0.0.0/8 is smaller
or equal to 32 bit, all routes from that network will be denied:
ip prefix -list abc deny 10.0.0.0/8 le 32
The following example: denies routes with mask length of more than 25 in network 204.70.1.24:
ip prefix-list abc deny 204.70.1.0/24 ge 25
The following example: permits all routes:
ip prefix-list abc permit any
61.5.6 Example of BGP Route Aggregation
The following example illusrates how to create aggregation routes in BGP.It may be created by route
redistribution or the using of conditional route aggregation function.
In the following example, command “redistribute static” is used to redistribute aggregation route 193.*.*.*:
ip route 193.0.0.0 255.0.0.0 null 0
!
router bgp 100
redistribute static
When there is at least one route in the routing table within the designated range, the following configuration
will create an aggregation route in BGP routing table. The aggregation route will be considered to be from your
AS, and has the “atomic” attribution, to indicate the possibilities of the loss of information.
router bgp 100
aggregate 193.0.0.0/8
The following example not only creates an aggregation route 193.*.*.*, but also prohibit it to broadcast the
more concrete routes to all the neighbours:
router bgp 100
aggregate 193.0.0.0/8 summary-only
61.5.7 Example of BGP Route Reflector
The following is an example of route reflector configuration. RTA, RTB, RTC, RTE all belong to the
same autonomous system AS200, RTA serves as route reflector, RTB and RTC are route reflector
clients, and RTE is normal IBGP neighbor. RTD belongs to AS100, and creates EBGP connection
with RTA, the configuration is illustrated as the following: