in server console

[cpt.joo]

hey iam trying to get this server thing to work and so far the problem is that only one person can see my server in the steam list and he can connect fine but when he gives out that ip of what the server says no one else can join and when i check the server console after leaving it on all day hoping some one had joined all i see is stuff like
No challange (then an ip)
Old challange (then an ip)
bad challange (then an ip) and i just see stuff like that anyone kno what i can do