Re: [NANOG] Introducing latency for testing?

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.