I bought a /24 bloc and a AS number.
I have opened two BGP sessions ISP1 and ISP2, from both i get default route + all metropolitan prefixes
What i want is to use both providers i really don’t care through the pachets are going, as long the traffic it’s shared somehow between them. (I have the same bandwidth from both) How i can do this ?
Also let’s assume one provider is down how i can keep /24 alive? or this is smth automatically done by the router?
Well, there are several different things that may be tweaked. But you can start with the AS-Path prepending on the sesson to the ISP that brings more traffic.
How it can be done is described here: http://wiki.mikrotik.com/wiki/Manual:Simple_BGP_Multihoming
well, thank you.
But now i have another problems.
It seems like i add the ip addresses for BGP 1 provider and BGP2 provider. They can’t be pinged from outside my country.
It’s strange, do i need to make sort of packet marking for each provider gateway ?
It’s difficult to say what happens but please use the Looking Glass sites of different (bigger) ISPs to check if they get your prefix. This is essencial. Also check via traceroute of your packet find their way to the routers of your ISP.
If your ISP gets your prefix but others don’t, you should talk to your ISP so they check their config. Maybe they are filtering your prefix.
There is no “Packet Marking” in BGP, but there is something called “BGP communities”, which can be used to influence the routing of your upstream ISP or get some information about the source of the prefixes (how or where they learned the prefix) you get from them. But usually you don’t need communities for basic connectivity.
On the router i have 3 gateways and 2 * /24 IP block
IPS1 - Gateway 1 & 2
ISP2 - Gateway 3.
The first /24 is older routed through my ISP1 with his AS, as a result i have in the routing table a static route for gateway, added by me.
Like this:
dst-address= 0.0.0.0/0 gateway=gateway1 distance=1 interface=WAN
The dynamic gateways from actual BGP they are in blue this means the gateway 1 is replaces them somehow.
It’s possible that this causes the problem ?
For traceroute the packets stops exaclty before my router.
This can’t work. You need to send the packets from the newer /24 to the correct gateway. The static route overrides a dynamic route. That’s why it doesn’t work.
I would change the routing so you announce both Prefixes, otherwise the first /24 has no redundancy. And kick the static route.
Ok i have deleted the static route, temporary to see if the BGP works.
Still the same.
But if i delete the static route and a BGP session also. It’s working !
With 2 BGP i have 2 gateways but still one of them is in blue. Maybe i have to do some extra settings ?
I was saying before if i stop one peer the /24 block starts to work. But this works only to one of the providers.
Is it posible that the ISP have some limits to external ? thus making conflicts ?
Also it is possible that my AS is not propagated yet? i bought the AS 24 hours ago.
. But still can’t ping my /24 block only if i disable one of the BGP peers.