BGP CONFIGURATION ADVERTISEMENT ISSUE

[dissai]

Hello Team,

I have configured bgp with my isp but is not able to see my routes advertising.kindly assist to review my configuration

router bgp 329
bgp log-neighbor-changes
neighbor 41.207.242.133 remote-as 473
neighbor 41.207.242.133 update-source GigabitEthernet0/0/0

!
address-family ipv4
network 102.110.54.0 mask 255.255.254.0
network 102.110.54.0 mask 255.255.255.0
neighbor 41.207.242.133 activate
neighbor 41.207.242.133 next-hop-self
neighbor 41.207.242.133 allowas-in
neighbor 41.207.242.133 soft-reconfiguration inbound
neighbor 41.207.242.133 route-map Orange_PUBLIC_BLOCK_TO_Tango out

exit-address-family
!
ip default-gateway 41.207.242.133
!
!
!

!
ip prefix-list Orange_PUBLIC_BLOCK_TO_Tango seq 5 permit 102.110.54.0/23
ip prefix-list Orange_PUBLIC_BLOCK_TO_Tango seq 10 permit 102.110.54.0/24
!
ip prefix-list Orange_SUPERNET seq 5 permit 102.110.54.0/23

route-map Orange_PUBLIC_BLOCK_TO_Tango permit 30
match ip address prefix-list Orange_DR_PUBLIC_BLOCK
set as-path prepend 329393 329393 329393 329393 329393
!
route-map Orange_PUBLIC_BLOCK_TO_Tango permit 10
match ip address prefix-list Orange_PUBLIC_BLOCK_TO_Tango
!
route-map Orange_PUBLIC_BLOCK_TO_Tango permit 20
match ip address prefix-list Orange_SUPERNET
!

ip prefix-list DEFAULT seq 5 permit 0.0.0.0/0
!
ip prefix-list DEFAULT_ROUTE_ONLY seq 5 permit 0.0.0.0/0
!
ip prefix-list Orange _DR_PUBLIC_BLOCK seq 5 permit 102.110.55.0/24

[Harold Ritter]

Hi @dissai ,

Adding the static route to null0 for 102.220.128.0/23 will not create a routing loop. It will rather send all traffic to that prefix that does not have a more specific route to the null0 interface. 

You should normally have more specific routes (102.220.128.0/24 and 102.220.129.0/24) installed in the local routing table. These more specific routes can be learned via the routing protocol running on your internal network or via static routes.

Regards,

[MHM Cisco World]

as I mention before and again I repeat you need to make sure the prefix in RIB before advertise it via BGP 

but ip route x.x.x.x to null0 is work??
Yes it work but we use this static route to null0 for aggragate not to advertise subnet not found in RIB 

for more info let me explain 
in R that have multi static route 
10.0.0.0/24 
10.0.1.0/24 
10.0.2.0/24 
I need to redistribute these static route into bgp 
I can do redistribute static (you can filter which static route you want to redistribute via route-map)

but that make bgp send three prefix I need to aggregate it 
here we can use 
ip route 10.0.0.0 255.255.0.0 null0 
then under bgp 

net 10.0.0.0 mask 0.0.255.255

this will form blackhole ?
NO 
but why?
the traffic arrive to router
the router now have four static route 
10.0.0.0/24
10.0.1.0/24
10.0.2.0/24 
10.0.0.0/16
the router check the longest match and sure one for three static route /24 will be use to forward traffic and hence there is no blackhole

note:- to be more accurate use /23 or /22 not jump from /24 to /16 becuase /16 can include many other subnet 

MHM

[MHM Cisco World]

neighbor 41.207.242.133 route-map Orange_PUBLIC_BLOCK_TO_Tango out <<- this must match same prefix we use in redistribute, we can know if the prefix add to bgp via show ip bgp 
can I see last config of this route-map 

by the way you dont need this route0map if you already filter the prefix in redistribute