BGP | Use /24 in 2 different BGP Instances (Same AS)

RouterOS Forwarding Protocols
1

Hello,

I have 2 routers and these routers have BGP configured and running.

What I want to do is to separate /24 and use these blocks into these two routers. Currently I am only able to use this block one of the router. Also even if I disable BGP session on X router, Y router cannot use these IPs even with the same config as router X and shown as IGP.

Router A configuration;

> routing bgp instance print 
Flags: * - default, X - disabled 
 0 *X name="default" as=65530 router-id=0.0.0.0 redistribute-connected=
      redistribute-static=no redistribute-rip=no redistribute-ospf=no 
      redistribute-other-bgp=no out-filter="" client-to-client-reflecti
      ignore-as-path-len=no routing-table="" 

 1    name="router_1" as=2****6 router-id=10.***.4 
      redistribute-connected=yes redistribute-static=no redistribute-ri
      redistribute-ospf=no redistribute-other-bgp=no out-filter="" 
      client-to-client-reflection=yes ignore-as-path-len=no routing-tab

> routing bgp peer print 
Flags: X - disabled, E - established 
 #   INSTANCE          REMOTE-ADDRESS                                   REMOTE-AS  
 0 E router_1            10.**3                                           34984      

> routing bgp advertisements print 
PEER     PREFIX               NEXTHOP          AS-PATH                            ORIGIN     LOCAL-PREF
rout... 123.456.789.0/24      10.***4                                             igp       


> routing filter print 
Flags: X - disabled 
 0   chain=FSIT_in invert-match=no action=accept set-bgp-prepend-path="" 

 1   chain=FSIT_out prefix=123.456.789.0/24 invert-match=no action=accept set-bgp-prepend-path="" 

 2   chain=FSIT_out invert-match=no action=discard set-bgp-prepend-path=""

Router B configuration;

> routing bgp instance print 
Flags: * - default, X - disabled 
 0 *X name="default" as=65530 router-id=0.0.0.0 redistribute-connected=
      redistribute-static=no redistribute-rip=no redistribute-ospf=no 
      redistribute-other-bgp=no out-filter="" client-to-client-reflecti
      ignore-as-path-len=no routing-table="" 

 1    name="router_2" as=2****6 router-id=10.***.6 
      redistribute-connected=yes redistribute-static=no redistribute-ri
      redistribute-ospf=no redistribute-other-bgp=no out-filter="" 
      client-to-client-reflection=yes ignore-as-path-len=no routing-tab

> routing bgp peer print 
Flags: X - disabled, E - established 
 #   INSTANCE          REMOTE-ADDRESS                                   REMOTE-AS  
 0 E router_2            10.**5                                           34984      

> routing bgp advertisements print 
PEER     PREFIX               NEXTHOP          AS-PATH                            ORIGIN     LOCAL-PREF
rout... 123.456.789.0/24      10.***6                                             igp       

> routing filter print 
Flags: X - disabled 
 0   chain=FSIT_in invert-match=no action=accept set-bgp-prepend-path="" 

 1   chain=FSIT_out prefix=123.456.789.0/24 invert-match=no action=accept 
     set-bgp-prepend-path="" 

 2   chain=FSIT_out invert-match=no action=discard set-bgp-prepend-path=""

I tried to filter IPs, but then I couldnt see these IPs in Advertisement list.

So I have 2 issues;

1 - How could I divide /24 into these 2 BGP sessions? like 123.456.789.0/26, 123.456.789.64/26 router_1, 123.456.789.128/26, 123.456.789.192/26 for router_2

2 - Why I couldnt use my IPs entirely on router2 after disabling router1’s BGP session? Do I need to wait more than 10-15 mins in order to get route list to update or? Because I waited almost 10 minutes but I wasn’t able to use it on router_2. Router_1 and Router_2 has same configuration as well as same permissions

Thanks in advance.

2
  1. You have to discus this with your ISP because they must do more configurations on this case to make IP summary and declare them in RIPE/ARIN policy!
  2. What are the IP of peer that you get connect because if there is a different IP: Have your ISP configured both Instances?