NistNet produces "No such device" errrors

I recently installed Nistnet on Slackware Linux version 2.4.20
(root@midas) (gcc version 3.2.2) to do some network utilization and
latency simulations.

It configured and compiled OK, but when I go to start it, either via
the GUI or commandline (cnistnet), it produces "No such device" errors
for any type of invocation.

Is it because I'm running a recent version of Slackware/Linux Kernel?

root@d7lxtest02:~# cnistnet -u
on: No such device
root@d7lxtest02:~# cnistnet -d
off: No such device
root@d7lxtest02:~# cnistnet -a 172.23.2.100 172.23.112.1 100 add new
addnistnet: 172.23.2.100:0 to 172.23.112.1:0 (prot 0 cos 100),
delay 0.000000 (sigma 0.000000 corr 0.000000),
bandwidth 0, drop 0.000000 (corr 0.000000),
dup 0.000000 (corr 0.000000),
drdmin 0, drdmax 0, drdcongest 0
util_binaddnistnet: No such device

Any help would greatly be appreciated!!

Thank you
Mike