[tlug] Adding latency to network connection

[Edward Middleton <emiddleton@example.com>]

I have a web application that I am trying to test but our network is
being a bit to responsive and low in latency.  What I need is to add
about 500ms latency to all packets going to the server.

There is a fairly outdated perl script called countertrace[1], that has
been updated by someone at redhat[2], which should accomplish this. 
Unfortunately, it appears that not only is the ip_queue obsoleted in kernel

Networking --->
[*] Networking support
        Networking options -->
[*] Network packet filtering framework (Netfilter) --->
        IP: Netfilter Configuration --->
<*> IP Userspace queuing via NETLINK (OBSOLETE)

but the user space bindings (libipq) appear to have been removed from
recent iptables (1.4.0).  The previous mentioned script uses perl
binding[3] to libipq.

Lucky (sort of) the new netfilter netlink queue

Networking --->
[*] Networking support
        Networking options -->
[*] Network packet filtering framework (Netfilter) --->
        Core Netfilter Configuration --->
<*> Netfilter NFQUEUE over NFNETLINK interface

also comes with a libipq compatibility library[4] which I used to
compile IPQueue[3].  This allowed me to run delay-net.pl[5] but it keeps
on dying with the following error.

Delay by 0.25 seconds
NFNETLINK answers: File exists
Could not initialize IPQ: Unable to bind netlink socket: Illegal seek

Does anyone have any ideas what is happening here, or how one might
debug this?  Alternately does anyone have a better method or adding
latency to a network connections?

Cheers,

Edward

1. http://michael.toren.net/code/countertrace/
2. http://people.redhat.com/berrange/notes/network-delay.html
3. http://search.cpan.org/~jmorris/perlipq-1.25/IPQueue.pm
4.
http://git.netfilter.org/cgi-bin/gitweb.cgi?p=libnetfilter_queue.git;a=blob;f=src/libipq_compat.c;h=61283ed6c6aed1919f2b12d76dbe83aa62c9468a;hb=HEAD
5. http://people.redhat.com/berrange/notes/network-delay/delay-net.pl