[NANOG] Introducing latency for testing?

[regnauld at catpipe.net (Phil Regnauld)]

Joel Jaeggli (joelja) writes:
> The freebsd dummynet driver is all about latency simulation...
> 
> http://www.scalabledesign.com/articles/dummynet.html
> 
> linux has a netem which can do the same thing
> 
> http://www.linux-foundation.org/en/Net:Netem

	dummynet is significantly easier to set up, especially for
	doing things like random packet reordering / packet loss (using the
	'prob' rule of ipfw + delay property with pipes).

	ipfw pipe 42 config bw 1024Kbit/s delay 6ms
	ipfw pipe 666 config bw 64Kbit/s delay 350ms

	ipfw add 10 prob 0.05 deny ip from 1.2.3.4 to any
	ipfw add 10 prob 0.8 pipe 666 ip from A to B
	ipfw add 10 prob 0.5 pipe 42 ip from A to B

	... and it runs.