Need some help about static routing tables on two hosts.

[Eliezer Croitoru]

On 7/26/2012 1:54 AM, Ondrej Zajicek wrote:
<SNIP>
>> i have tried to use bgp in a local as between the  master and the LB but
>> it seems that on the LB when he gets the static route it states the
>> route:
>> 0.0.0.0 .... unreachable.
>
> This is probably caused by 'gateway recursive' mode on BGP (default for IBGP).
> See 'gateway direct' option and then question 'IBGP does not work ...' in FAQ:
>
> https://git.nic.cz/redmine/projects/bird/wiki/FAQ
>
>
>
> Another, completely different way how to implement this would be that
> 'master' would just announce which proxies are 'usable' (through one BGP
> session) and LBs would fill all tables from this information. That could
> be done using static recursive routes. For example for proxy 10.100.1.10
> we will use auxiliary pseudo-IP 10.100.2.10 and if 10.100.1.10 is
> usable, master will propagate pseudo-route:
>
> 10.100.2.10/32 via 10.100.1.10
>
> to LB. On LB, there will be static recusive route:
>
> route default recursive 10.100.2.10
>
> If master propagated that pseudo-route, this recursive route will appear as:
>
> route default via 10.100.1.10
>
> otherwise it will appear as
>
> route default unreachable
>
> You could have such recursive route for each proxy so you will get a
> table with a set of default routes that are either corrrect or
> unreachable. Unfortunately being unreachable does not lower route
> priority, so you would have to use another table connected with pipe and
> in pipe filter you do something like 'if dest = RTD_UNREACHABLE then
> prio = 1'. this will move all unreachable routes to the bottom, so the
> reachable route with highest configured priority will be used. This have
> to be replicated for each table on LB (probably with different priority
> for each static routes so that different one will be used as best one),
> only the table with pseudo-routes received from master will be shared.
>
> It is pretty complex and i don't know if it does what you really need,
> but it should work.
>
well i have tried to implement the mutipath idea i had but it seems that 
on bgp i cant send multipath + weight from one host static protocol to 
another.
is there any way to import a multipath statement with some coding?
what i mean is that i will advertise multiple statements of default 
route that are under 100 and 1 means unreachable.
and on the destination LB i will gather them all together and will put 
them in a multipath arrray.

since im not that experience with routing protocols i lack some knowledge.

Thanks,
Eliezer


-- 
Eliezer Croitoru
https://www1.ngtech.co.il
IT consulting for Nonprofit organizations
eliezer <at> ngtech.co.il