Re: Multiple routing table support commited

Zaphod Beeblebrox wrote:
> On Fri, May 9, 2008 at 8:52 PM, Julian Elischer <julian_at_elischer.org 
> <mailto:julian_at_elischer.org>> wrote:
> 
>     I have committed the base of teh Multi-routing-table support.
>     I am current;y waiting for it to loop back to me before a final
>     make universe test, but I think it should be ok.
>     if you do nothing you should not see any difference.
> 
>     for a description  of what and how, look at:
> 
>     http://perforce.freebsd.org/fileViewer.cgi?FSPC=//depot/user/julian/routing/plan.txt
> 
> 
>  >From my read of your file, this doesn't address FreeBSD's utter lack 
> of what they often call an RIB --- where routes are chosen to be put 
> into the FIB.  Zebra does this to some extent, but there is one glaring 
> case where zebra cannot fix the problem and FreeBSD's actions need be 
> improved.

There is a reason this stuff is called FIB stuff and not RIB stuff..


> 
> Consider a colocation facility where customer equipment is on a vlan and 
> every one of these vlan's has two routers (each advertising RIP default 
> routes to the customer equipment).  All of these routers synchronize 
> with OSPF.
> 
> Now ... if vlan 10 on router-a and router-b both service a particular 
> customer, you would (on router-a)
> 
> ifconfig vlan10 192.168.10.1/24 <http://192.168.10.1/24>

what has http got to do with ifconfig?
(or did your email agent add that?)


> 
> ... and on router-b
> 
> ifconfig vlan10 192.168.10.2/24 <http://192.168.10.2/24>
> 
> ... and then the customer would take the other addresses on that network 
> and listen to RIP for his default route.
> 
> But there's a problem.  When you type this command on router-a, it will 
> dutifully advertise 192.168.10.0/24 <http://192.168.10.0/24> to OSPF ... 
> including to router-b... at which point the ifconfig command on router-b 
> will fail unless you offline OSPF on router-b (which is an unattractive 
> solution).
> 
> Now... some would argue that for all other uses of multiple routes, 
> zebra forms an adequate solution.  However, it does not address this 
> particular problem and there are far more uses of multiple identical 
> routes (including multipath, etc) s.t. FreeBSD really does need a 
> multiple route plan.

yes but that's not the problem I'm trying to solve.

It IS however related to the multipath code that Qing Li committed a 
couple of weeks ago..