BGP stopped working in 4.2

RouterOS Forwarding Protocols
1

after upgrading to routeros 4.2, BGP stopped working

2

please be more definite

3

it shows peering established but not advertising my ip block.

my configuration is as under:

instance: name=default, AS=my ASN, Redistributed Static, Redistributed connected
peers: name=myISP, instance=default, Remote Address=IP of ISP, Remote AS=ISP’s ASN, multihop=yes, route reflect=no
networks: network=my ip block to advertise, synchronize=yes

I don’t know what I’m doin wrong. Earlier it was working fine. currently not using any filter list.

4

from what version have you upgraded?

also, you have ‘synchronize’ option switched on - do you have a routes you want to advertize in your routing table?

5

it’s working now. i referred mikrotik wiki and did exactly same as described in the wiki.

can i do load balancing with BGP ?? like creating filters??

6

BGP is for route distribution, not LB. you may use any load-balancing scheme you want (in parallel with BGP)

7

what load-balancing scheme you are referring to ?? is it hardware based or software based.

can you please explain me in details with supporting document/diagram.

thanks

8

what kind of load balancing do you need? with BGP, you can advertise your different PI-addresses to different uplink providers, so that incoming traffic go through that exact provider

9

load balancing in internet bandwidth. I have two DS3 coming in from two providers and want to use both links simultaneouly so that
total 90Mbps bandwidth I’ll get to use.

If I route traffic to two providers using filters, what will be the outcome. Only outbound traffic will go from two
providers or incoming traffic also will select the same path which it used for outbound ? Or for incoming it will select the best path? Coz I’m advertising entire pool with both the providers.

can you please share configuration as well?

thanks

10

as I said, you have to advertise different subnets to different providers - so that traffic to each block of addresses go via corresponding provider

for failover, use Routing Filters to set bgp-prepend at backup block of addresses on each link

11

You can use AS path prepending to make incoming traffic have a slight preference for the less prepended link. You probably won’t be able to get 50/50, but it helps some.

More drastically, you can break your netblock in two, and advertise the big netblock out the connection that is too full, and advertise it’s two half sized blocks on the link that is too empty, and routers choose more specific routes mostly unless they are filtering by network size, and will choose to send via the more specific route. i.e. if you have 192.168.0.0/23, you could advertise that via one link and 192.168.0.0/24 and 192.168.1.0/24 via the other link.

For outgoing, send a large block (say 0.0.0.0/4) out one link and it will go that link unless there is a specific BGP route to send it otherwise.

12

thanks for your solution.

as chupaka said

you have to advertise different subnets to different providers - so that traffic to each block of addresses go via corresponding provider

do I need to inform providers also that one should advertise only this much block and other should advertise remaining???

If so, then what would happen if one link fails.

can you please share configuration for better understanding ??