[tlug] Re: Adding latency to network connection

[Edward Middleton <emiddleton@example.com>]

Alberta, John,

Sorry bit of a delay in replying.  I had already tried John's suggestion
which worked well enough for what I needed.

John Fremlin wrote:
> Use tc netem?
>
> http://www.linuxfoundation.org/en/Net:Netem
>
>  Emulating wide area network delays
>
> This is the simplest example, it just adds a fixed amount of delay to all packets going out of the local Ethernet.
>
>  # tc qdisc add dev eth0 root netem delay 100ms  

Thanks that was pretty much what I was after.  It obviously only adds
the latency to outgoing packets so I also needed to add latency for
incoming packets.

# modprobe ifb
# ip link set dev ifb0 up
# tc qdisc add dev eth0 ingress
# tc filter add dev eth0 parent ffff: protocol ip u32 match u32 0 0 flowid 1:1 action mirred egress redirect dev ifb0
# tc qdisc add dev ifb0 root netem delay 500ms

If you are trying this at home you might also want ;)

# tc qdisc del dev eth0 root
# tc qdisc del dev ifb0 root

Edward