Suppressing Error Message is not working

I need to suppress the error message for commands. I have given the command like below

lsb_release -dr 2>/dev/null

But it is not working.

Am testing with Red Hat Linux release 9. Guide me.

Thanks in advance

what does this show?

strace -e=open,dup,dup2  lsb_release

It could be that something is causing stderr to be other than file descriptor 2. I'm assuming you did not previously redirect stderr with exec:

exec 2>&4 

If you're using a raw console, it may be these are messages from the system logger and not merely printed by your process.