Except we might very well reach 1+ million routes soon without accepting longer prefixes than /24. Also route updates is a concern - do I really need to be informed every time someone on the other end of the world resets a link?
On 3 October 2015 at 12:57, William Waites <wwai...@tardis.ed.ac.uk> wrote: > On Sat, 3 Oct 2015 12:42:01 +0200, Baldur Norddahl < > baldur.nordd...@gmail.com> said: > > > 2 million routes will not be enough if we go full /27. This is > > not a scalable solution. Something else is needed to provide > > multihoming for small networks (LISP?). > > It's not too far off though. One way of looking at it is, for each > extra bit we allow, we potentially double the table size. So with 500k > routes and a /24 limit now, we might expect 4 million with /27. Not > exactly because it depends strongly on the distribution of prefix > lengths, but probably not a bad guess. > > Also there are optimisations that I wonder if the vendors are doing to > preserve TCAM such as aggregating adjacent networks with the same next > hop into the supernet. That would mitigate the impact of wanton > deaggregation at least and the algorithm doesn't look too hard. Do the > big iron vendors do this? > > -w > > -- > William Waites <wwai...@tardis.ed.ac.uk> | School of Informatics > http://tardis.ed.ac.uk/~wwaites/ | University of Edinburgh > https://hubs.net.uk/ | HUBS AS60241 > > The University of Edinburgh is a charitable body, registered in > Scotland, with registration number SC005336. >
