Editing FreeBSD Reference (section)

== Setting up bandwidth caps on a jail ==

If there's a situation where a VPS (or VPSs) on a jail are spiking bandwidth, but it's hard to tell who's the culprit, you can put in a global ipfw rule that will limit the connect speed for the entire server and/or each IP on the server.

The commands to limit the overall outbound connect speed are:
 /sbin/ipfw pipe 1 config bw 40Mbit/s
 /sbin/ipfw add 1 pipe 1 ip from me to any

The commands to limit the individual outbound connect speed are:
 /sbin/ipfw pipe 2 config bw 12Mbit/s mask src-ip 0xffffffff
 /sbin/ipfw add 2 pipe 2 ip from me to any