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How to advertise more specific route over aggregate route via BGP?

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TitleHow to advertise more specific route over aggregate route via BGP?
Symptoms
BGP route map is allowing the route to be advertised which isnot present inthe route Map:
MLX-A(10.18.7.49)---------MLX-B (10.18.7.50)
MLX-A (10.18.7.49)
BGP Config
router bgp
local-as 310
neighbor 10.84.223.3 remote-as 310
address-family ipv4 unicast
network 10.84.210.0/23
network 22.22.22.2/32
network 216.20.240.0/23
network 5.5.4.0/23
redistribute connected
neighbor 10.84.223.3 route-map out BGP-OUT
exit-address-family
telnet@config)#sh route-map BGP-OUT
route-map BGP-OUT permit 30
match ip address 27

access-list 27 permit 216.20.240.0 0.0.0.255
Environment
Software Release: 5100b
Fixed in Version: N/A
Cause
Resolution
Modify the Access listto match the exact prefix by adding a host statement in the access-list.

In the ACL below, the first address is the route prefix and the second address is the prefix mask.
access-list17 permit ip host 216.20.240.0 host 255.255.255.0
route-map BGP-OUT permit 30
match ip address17

When applying the route-map using the above access-list, it fixes the issue andadvertises one route 216.20.240.0/24 as per access list.

Alternatively, prefix list can also be used to advertise the specific route.

ip prefix-list test seq 10 permit 216.20.240.0/24

(config-bgp)# neighbor 10.84.223.3 prefix-list test out

After applying this access-list, it then advertises one route which is allowed in the route map.
telnet@)# sh ip bgp neighbors 10.84.223.3 advertised-routes
There is 1 route advertised to neighbor 10.84.223.3.
Status A:AGGREGATE B:BEST b:NOT-INSTALLED-BEST E:EBGP I:IBGP L:LOCAL
Prefix Next Hop MED LocPrf Weight Status
AS_PATH:
1 216.20.240.0/24 10.84.223.2 0 100 32768 BL
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