[Xorp-hackers] New consolidated Xorp performance improvement patch uploaded.

[Bruce M Simpson]

Kristian Larsson wrote:
> Will it be possible to set administrative distance
> per route? This is _very_ useful for having
> floating static routes.
>   

OK, I just spent some moments reading code. If someone writes a patch to 
implement floating statics, I'm happy to review it, it's not on my plate 
at the moment.

It's certainly possible, as the admin distance is part of each route 
entry in the RIB; the per-route admin distance is used in comparisons 
whenever a route table change happens, when the RIB is deciding which 
route to replace.

It is gnarly in that it means manipulating the admin distance on a 
per-route basis, which is a use case which neither the XRLs nor the 
static_routes syntax are set up to deal with. The code to do this would 
need to be added. The XRLs to add/replace routes are specialized for 
interface routes, I see no reason why they couldn't be specialized for 
adding/changing a route with admin distance.

cheers
BMS

[P.S. The thing with floating statics is: there's something of a case 
for implementing them in the host's forwarding plane too, as they are 
very useful for folk who are hot swapping network interfaces and don't 
have a need to run a full routing daemon.
I've been thinking about doing same for FreeBSD. The disadvantage for 
XORP in doing it that way, however, is that the FEA would need to be 
taught to look for host based floating statics and update its state 
appropriately.]