(Error in makefile)RTNETLINK answers: File exists

Question

This is my makefile:

delay:
    tc qdisc add dev eth0 root netem delay 0ms
test4_s_delay:delay
    ./a.out 10 10 1 2 3 1 1 20 | tee server_delay.txt

but,I am getting the following error on executing the makefile:

root@superwii-laptop:/home/superwii/Desktop/Amogh# make test4_s_delay
tc qdisc add dev eth0 root netem delay 0ms
RTNETLINK answers: File exists
make: *** [delay] Error 2

I am unable to get through the error.please help.

Answer 1

Looks like your executable tc is exiting with non-zero value of 2.

Try running the command tc qdisc add dev eth0 root netem delay 0ms and see if it runs fine.