На AS254 передаются все маршруты. На все остальные роутеры передается только маршрут до AS254.

root@vds2032565:~# telnet 0 2605
Trying 0.0.0.0...
Connected to 0.
Escape character is '^]'.

Hello, this is Quagga (version 1.2.4).
Copyright 1996-2005 Kunihiro Ishiguro, et al.


User Access Verification

Password: 
ihor> enable 
ihor# show running-config 

Current configuration:
!
hostname ihor
password zebra
log stdout
!
router bgp 2021
 bgp router-id 10.123.156.1
 neighbor 10.123.156.3 remote-as 254
 neighbor 10.123.156.3 description my_home_AS254_net254
 neighbor 10.123.156.3 update-source tap0
 neighbor 10.123.156.4 remote-as 22
 neighbor 10.123.156.4 description primorstroi_AS22_net22
 neighbor 10.123.156.4 update-source tap0
 neighbor 10.123.156.4 route-map NET_254 out
 neighbor 10.123.156.5 remote-as 44
 neighbor 10.123.156.5 description kommunar_AS44_net44
 neighbor 10.123.156.5 update-source tap0
 neighbor 10.123.156.5 route-map NET_254 out
 neighbor 10.123.156.6 remote-as 20
 neighbor 10.123.156.6 description vkus_AS20_net20
 neighbor 10.123.156.6 update-source tap0
 neighbor 10.123.156.6 route-map NET_254 out
!
 address-family ipv6
 exit-address-family
 exit
!
ip prefix-list FROM_AS254 seq 10 permit 192.168.254.0/24
!
route-map NET_254 permit 20
 match ip address prefix-list FROM_AS254
!         
line vty
!
end
ihor#