Document revision 5-Sep-2002
This document applies to the MikroTik RouterOS 2.6
MikroTik RouterOS supports BGP Version 4, as defined in RFC1771.
The MikroTik RouterOS implementation of the BGP has the following features:
[admin@MikroTik] > system package print Flags: I - invalid # NAME VERSION BUILD-TIME UNINSTALL 0 system 2.6beta4 aug/09/2002 20:22:14 no 1 rip 2.6beta4 aug/09/2002 20:33:41 no 2 ppp 2.6beta4 aug/09/2002 20:28:01 no 3 plist 2.6beta4 aug/09/2002 20:32:58 no 4 pppoe 2.6beta4 aug/09/2002 20:29:18 no 5 pptp 2.6beta4 aug/09/2002 20:28:43 no 6 ssh 2.6beta4 aug/09/2002 20:25:31 no 7 advanced-tools 2.6beta4 aug/09/2002 20:53:37 no 7 bgp 2.6beta4 aug/09/2002 20:34:22 no 9 ipsec 2.6beta4 aug/09/2002 20:24:51 no 10 ospf 2.6beta4 aug/09/2002 20:34:08 no [admin@MikroTik] >
Hardware Resource Usage
The BGP requires additional RAM for storing the routing information.
It is recommended to have 128MB or more RAM.
BGP Description
For BGP description and implementation guidelines please refer to the readings
mentioned in the list of Additional Resources.
Current document discusses BGP configuration for MikroTik RouterOS.
BGP Setup
The BGP management can be accessed under the /routing bgp submenu.
[admin@MikroTik] routing bgp> print
enabled: no
as: 0
router-id: 0.0.0.0
redistribute-static: no
redistribute-connected: no
redistribute-rip: no
redistribute-ospf: no
state: disabled
[admin@MikroTik] routing bgp> set as=65002 router-id=159.148.147.206 enabled=yes \
\... redistribute-connected=yes
[admin@MikroTik] routing bgp> print
enabled: yes
as: 65002
router-id: 159.148.147.206
redistribute-static: no
redistribute-connected: yes
redistribute-rip: no
redistribute-ospf: no
state: running
[admin@MikroTik] routing bgp>
Argument description:
enabled - enable or disable the BGP
as - autonomous system number
router-id – the Router ID
redistribute-connected – if set to yes, then the router will redistribute the information about all connected routes, i.e., routes to networks, that can be directly reached from the router
redistribute-static – if set to yes, then the router will redistribute the information about all static routes added to its routing database, i.e., routes, that have been created using the /ip route add command of the router
redistribute-rip – if set to yes, then the router will redistribute the information about all routes learned by the RIP protocol
state - status of the BGP:
- disabled - not working, has been disabled
- running - working
Usually you want to redistribute connected and static routes, if any. Therefore change the settings for these arguments and proceed to the BGP networks.
To tell the BGP router which networks to advertise, use the /routing bgp network add command:
[admin@MikroTik] routing bgp network> add network=159.148.150.192/27 [admin@MikroTik] routing bgp network> print # NETWORK 0 159.148.150.192/27 [admin@MikroTik] routing bgp network>
Here, the network argument is used to specify the network/mask to advertise. You can add to the list as many networks as required. Also, you can use 0.0.0.0/0 to advertise all networks.
Note, that the OSPF uses network list for different purpose - to determine where to send updates.
You need to specify the BGP peer with whom you want to exchange the routing information. The BGP exchanges routing information only if it can establish a TCP connection to its peer. You can add as many peers as required, for example:
[admin@MikroTik] routing bgp peer> add remote-address=192.168.0.254 remote-as=217 [admin@MikroTik] routing bgp peer> print # REMOTE-ADDRESS REMOTE-AS MULTIHOP ROUTE-REFLECT PREFIX-LIS... PREFIX-LI... 0 192.168.0.254 217 no no none none [admin@MikroTik] routing bgp> peer print status # REMOTE-ADDRESS REMOTE-AS STATE ROUTES-RECEIVED 0 192.168.0.254 217 connected 1 [admin@MikroTik] routing bgp>
Argument description:
remote-address - address of the remote peer
remote-as - AS number of the remote peer
multihop - if set to yes, allows BGP sessions, even when the neighbor is not on a directly connected segment. The multihop session is not established if the only route to the multi-hop peer's address is the default route (0.0.0.0).
route-reflect - defines whether to further redistribute routes learned from the router of the same AS or not. If enabled, can significantly reduce traffic between routers in the same AS
prefix-list-in - Name of the filtering prefix list for receiving routes
prefix-list-out - Name of the filtering prefix list for advertising routes
state - Shows the status of the BGP connection to the peer. Can be not-connected or connected
routes-received - Shows the number of received routes from this peer
The prefix lists should be defined under the /routing prefix-list. See corresponding manual for the details on using prefix lists.
Additional Resources
Recommended readings for guidelines on building BGP networks:
(Not complete yet)