eBGP On V7.21.1

RouterOS Forwarding Protocols
1

I am creating a BGP connection with Cogent. The connection was established, but it was not able to send out the prefix.

I guess my out.network or filter has a problem.

Here is the Config:

/ip/firewall/address-list> print where list=BGP-OUT-V4

Columns: LIST, ADDRESS, CREATION-TIME

LIST ADDRESS CREATION-TIME

0 BGP-OUT-V4 144.79.252.0/24 2026-01-23 18:45:02
1 BGP-OUT-V4 154.22.137.0/24 2026-01-23 18:45:39

routing/filter/rule/print where chain=bgp-out-v4
Flags: X - disabled, I - inactive
0 ;;; added by filter-wizard
chain=bgp-out-v4 rule="if (dst in BGP-OUT-V4) { accept }"

routing/bgp/connection/print where name=bgp-V4
Flags: D - dynamic, X - disabled, I - inactive
0 name="bgp-V4" instance=BGP-ASXXXXX
remote.address=154.18.6.96/32 .as=XXX
local.address=154.18.6.97 .role=ebgp
connect=yes listen=yes routing-table=main as=XXXXX afi=ip
output.filter-chain=bgp-out-v4 .network=BGP-OUT-V4
.default-originate=never

Please help me with this, is there anything wrong with the filter or the address list.

Thanks!

2

Make sure you have a synced IGP route in the routing table for all the networks you want to advertise.

3

in a simple words... do you have these prefixes in your routing table?

4

Thanks! Looks like problem solved.

5

Thanks! Looks like problem solved with adding blackhole route.