[Xorp-hackers] BG 172

[Pavlin Radoslavov]

> Eddie Kohler wrote:
> > > set route static route4 10.0.0.0/24 next-hop 172.16.1.1
> > > set route static route4 10.0.0.0/24 next-hop 172.16.1.2
> >
> > It is really problematic when code or configuration statements silently
> > change meaning from one release to the next!
> 
> No, it isn't problematic. Xorp doesn't handle non-unique leaf nodes at all 
> at the moment, so there is nothing that breaks really. Policy with new 
> set command should be clear: it must change unique nodes and add 
> non-unique ones.

I believe the point Eddie was trying to make is that someone
accustomed with the current "set" command being used only to change
values of single-value nodes will suddenly start seeing different
behavior with the new "set" if we redefine a single-value node as a
multi-value node.

Yes, this could be a problem when using xorpsh, so at least we
should try to avoid redefining a single-value node as a multi-value
(or vice versa).

> As sidenote (it shouldn't matter any more), what would happen in 
> hypotetical case (if multiple nexthops would be supported) with current 
> set behaviour?
> 
> create route static route4 10.0.0.0/24 next-hop 172.16.1.1
> create route static route4 10.0.0.0/24 next-hop 172.16.1.2
> set route static route4 10.0.0.0/24 next-hop 172.16.1.3

The first two commands will create two next-hop nodes: 172.16.1.1
and 172.16.1.2.
The third command will return a syntax error.

Pavlin