> With the current “default free zone” containing around 1,000,000 routes
Back in ~1998 I was tasked with building a route collector/looking glass machine for an internet exchange point (sadly defunct). I remember the day we switched the collector on and acquired "all the routes", there were ~98,000 of them, you could've knocked me over with a feather. It was like looking into the Total Perspective Vortex. Having been out of that game for many years now I'd no idea we were up to 1M routes...wow. One of the RIPE conferences I attended back then there was much concern about the rapidly increasing size of the global routing table and whether vendors could build hardware powerful enough to keep up.
For anyone interested the route collector was built on FreeBSD (3.0 I think) and Zebra[0].
And finally, what cracking blog, especially stuff like this:
Just looked at my router in docklands, 833,000 IPv4 routes, from 1.0.0.0/24 to 223.255.64.0/18
32,528 of them are in the 103.0/8 range, but on the other hand 21.0.0.0/8 is advertised once, no subnets at all. (same with 26, 28, 30, 33, 73. I don't have a route for 9.0.0.0/8 aside from 9.9.9.0/24.
Two very different things are going on to cause the smaller number of IPv6 routes.
One of course is that some Autonomous Systems don't advertise IPv6, either they have no globally routable IPv6 or they only achieve IPv6 via a tunnel and so that's only advertised via their tunnel provider.
But more important, many Autonomous Systems only need to advertise one prefix in IPv6 because it's big enough. Even if your needs grow, because we'd done this before and because IPv6 addresses are plentiful the allocations were deliberately sparse - so your RIR can give you the adjacent addresses, meaning you still only need one route entry for your larger space.
With IPv4 a provider may find itself advertising hundreds or even sometimes thousands of routes to the same Autonomous System since the addresses they need to advertise aren't contiguous.
I remember back in 2008 when we reached 256k prefixes, the then limit of Cisco 6500 and 7600 routers, which were kind of the workhorses for a bunch of ISPs. Lots of places were buying memory expansion for those devices to cope. 6 years later, 512k day occurred.
Interesting historical perspective, thanks. And to put that growth into more recent perspective, in the last 7 years we have had a "512 K" day and "768 K" day. See:
> With the current “default free zone” containing around 1,000,000 routes
Back in ~1998 I was tasked with building a route collector/looking glass machine for an internet exchange point (sadly defunct). I remember the day we switched the collector on and acquired "all the routes", there were ~98,000 of them, you could've knocked me over with a feather. It was like looking into the Total Perspective Vortex. Having been out of that game for many years now I'd no idea we were up to 1M routes...wow. One of the RIPE conferences I attended back then there was much concern about the rapidly increasing size of the global routing table and whether vendors could build hardware powerful enough to keep up.
For anyone interested the route collector was built on FreeBSD (3.0 I think) and Zebra[0].
And finally, what cracking blog, especially stuff like this:
https://blog.benjojo.co.uk/post/eve-online-bgp-internet
[0]: https://en.wikipedia.org/wiki/GNU_Zebra