Need help

[mithu_n123]

Dear All,

Hope you are well. I am facing a problem in e-BGP, I have 2 upstream, and I have 4 IP blocks. I want to upload 2 IP blocks from MANGO and another 2 IP blocks from L3. But I failed, every time my all IP blocks are uploaded from MANGO. Please give me a solution how to resolve the problem. Please check my network diagram in attachment.

[mludwig89]

Mithu,

By upload i assume you mean advertise. If this is the case, my recommendation would be to create a pre-fix list and route-map. Then apply the route map to the neighbor that you would like. Once you have done this, you will not have dynamic failover in the case that L3 or Mango is to go down. If you would like to do this you should look into AS-PATH PREPEND. I have attached an example of a route-map to only advertise specific routes to an eBGP neighbor. 

ip prefix-list Permit-Outbound seq 5 permit x.x.0.0/16
ip prefix-list Permit-Outbound seq 10 permit x.x.0.0/16
ip prefix-list Permit-Outbound seq 15 permit x.x.x.x/30

route-map PermitOutbound permit 20
match ip address prefix-list Permit-Outbound

router bgp 65xxx
network x.x.0.0 mask 255.255.0.0
network x.x.0.0 mask 255.255.0.0
network x.x.x.x mask 255.255.255.252
neighbor x.x.x.x remote-as 209
neighbor x.x.x.x route-map PermitOutbound out

[mithu_n123]

Dear

Thanks for your help. According to your post I configured it. But It does't work properly. I allowed 2 IP block (43.240.100.0/24, 43.240.101.0/24) from MANGO, when I check It form my "MN-ISP-AR-R3" then it move from MANGO. I also tried to ASPath Prepending but there was same result. Please check the trace report. Please give me an another solution. 

MN-ISP-AR-R3#traceroute 8.8.8.1 source 43.240.103.1
Type escape sequence to abort.
Tracing the route to 8.8.8.1
VRF info: (vrf in name/id, vrf out name/id)
1 192.168.1.1 [AS 200] 12 msec 10 msec 10 msec
2 4.4.4.2 [AS 200] 21 msec 21 msec 20 msec
3 192.168.2.1 [AS 200] 20 msec 21 msec 20 msec
4 192.168.4.2 [AS 200] 10 msec 9 msec 10 msec
 

[mludwig89]

Please run the following commands on MN-ISP-CR-R1 and attach the config to the post. 

term leng 0

sh run

*** I assume you are doing this in GNS3 or VIRL because of the IP addresses you are using but if this is live gear please remove in sensitive information (ex: passwords / snmp etc).