After installing the latest version of the Intel® Power Gadget, I noticed that the GPU speed on my late-2013 13" MacBook Pro never really deviated from 0.55 GHz. (Well, except when playing high definition video, then it goes to 0.4 GHz.)

So I found these WebGL demos. It's really unbelievable what can be done in a browser these days. And yes, most of these will stress both the CPU and GPU to the max.

Permalink

Documentation ASNs and IP prefixes

▼ As you may have noticed, I write about BGP from time to time. When coming up with example configurations, there's always the challenge of which AS numbers and IP addresses/prefixes to use. Although it's unlikely people will simply copy numbers and addresses from examples into their own BGP configurations, experience with NTP has shown that this can be a real problem, so it's a good idea to avoid "real" addresses and numbers in examples.

One obvious choice for IPv4 addresses in examples is the RFC 1918 space: 10.0.0.0/8, 172.16.0.0/12 and 192.168.0.0. For IPv6, you could use the unique (site) local addresses (ULA, RFC 4193: fc00::/7, or, more precisely, the ones you get to generate yourself in fd00::/8. I wouldn't recommend using the original site local IPv6 addresses (fec0::/10), as these are "deprecated" in RFC 3879.

For AS numbers, there's the private range 64512 - 65534 (16 bit) and 4200000000 - 4294967294 (32 bit) in the IANA registry.

However, there are also address and AS number ranges specifically set aside for example and documentation use. These have the advantage that they can easily be recognized as being intended for documentation, and won't clash with ranges used in private networks. They are:

16-bit AS numbers: 64496 - 64511 (RFC 5398)
32-bit AS numbers: 65536 - 65551 (RFC 5398)
IPv4 addresses: 192.0.2.0/24, 198.51.100.0/24, 203.0.113.0/24 (RFC 5737)
IPv6 addresses:2001:db8::/32 (as in "debate") (RFC 3849)

I actually didn't know about the documentation AS number ranges and the second and third IPv4 documentation ranges. The extra IPv4 ranges will be very useful, as just 192.0.2.0/24 often isn't enough in more complex BGP examples, especially as I don't want to give the impression that it's possible to deaggregate a /24 into smaller parts. The 16-bit documentation AS numbers will also be useful. Unfortunately, the 32-bit ones aren't really useful as they look too much like 16-bit numbers. However, the 65552 - 131071 range is "reserved" so I guess I'll continue to use AS numbers in the 9xxxx range as examples of 32-bit ASNs.

Permalink - posted 2015-04-24

"Get Your Hands Dirty with BGP" tutorial at next month's RIPE meeting

At the RIPE-70 meeting next month in Amsterdam I'll be doing a tutorial on BGP: "Get Your Hands Dirty with BGP".

This is the "light" version of the regular BGP training that I do several times a year: the theory part will be around 30 minutes and then about two hours of hands-on BGP using the Quagga routing software running in a virtual machine on the participant's laptops.

If you're attending the RIPE meeting and you're interested in participating, please go to this page and send me an email so I know how many people to expect.

Permalink

→ Keynote '09: Connecting Objects with an Adjustable Line

I honestly thought I knew pretty much everything there is to know about Apple's Keynote presentation program. I was wrong. I didn't know this:

When you want to join two objects with a line, the easiest way to do it is to use a connection line (rather than creating a separate line as a shape). Two objects joined by a connection line remain joined even if you reposition the objects on the slide canvas.

Permalink

→ 9 More Mind-Blowing WebGL Demos

Documentation ASNs and IP prefixes

Documentation ASNs and IP prefixes

Rolschaatsroutebordjes!

"Get Your Hands Dirty with BGP" tutorial at next month's RIPE meeting

Spring has arrived

→ Keynote '09: Connecting Objects with an Adjustable Line