public OnPlayerConnect(playerid)
{
    if(IsPlayerNPC(playerid)) {
        new server_IP[16];
        format(server_IP, 16, "127.0.0.1");

        if(strcmp(ConnIP,server_IP,true) != 0) {
            Ban(playerid); // Ban is the safest thing here, as if you kick, they can still flood you with endless connections
            return 0;
        }
    } 
    return 1;
}

// maxips FS limits the number of players connecting from a
// single IP address.

#include <a_samp>

#define MAX_CONNECTIONS_FROM_IP     3

//---------------------------------------------

public OnFilterScriptInit()
{
    printf("\n*** Player IP limiting FS (maxips) Loaded. Max connections from 1 IP = %d\n",MAX_CONNECTIONS_FROM_IP);
}

//---------------------------------------------
// GetNumberOfPlayersOnThisIP
// Returns the number of players connecting from the
// provided IP address

stock GetNumberOfPlayersOnThisIP(test_ip[])
{
    new against_ip[32+1];
    new x = 0;
    new ip_count = 0;
    for(x=0; x<MAX_PLAYERS; x++) {
        if(IsPlayerConnected(x)) {
            GetPlayerIp(x,against_ip,32);
            if(!strcmp(against_ip,test_ip)) ip_count++;
        }
    }
    return ip_count;
}

//---------------------------------------------

public OnPlayerConnect(playerid)
{
    new connecting_ip[32+1];
    GetPlayerIp(playerid,connecting_ip,32);
    new num_players_on_ip = GetNumberOfPlayersOnThisIP(connecting_ip);
    
    if(num_players_on_ip > MAX_CONNECTIONS_FROM_IP) {
        printf("MAXIPs: Connecting player(%d) exceeded %d IP connections from %s.", playerid, MAX_CONNECTIONS_FROM_IP, connecting_ip);
        Kick(playerid);
        return 1;
    }

    return 0;
}
    
//---------------------------------------------

#include <a_samp>

#define MAX_CONNECT_IN_ROW 3
#define MAX_REJOIN_TIME 4000
new ipCheck[25], IPfound, IPtime;

public OnPlayerConnect(playerid)
{
    new pIP[25];
    GetPlayerIp(playerid, pIP, 25);
    if(strcmp(ipCheck, pIP, false) == 0 && ( GetTickCount() - IPtime ) < MAX_REJOIN_TIME )
    {
        IPfound++;
        if(IPfound > MAX_CONNECT_IN_ROW)
        {
            new str[100];
            format(str, 100, "banip %s", pIP);
            SendRconCommand(str);
            Kick(playerid);
            IPfound=0;
        }
    }
    else
    {
        IPfound=0;
    }
    format(ipCheck, 25, "%s", pIP);
    
    IPtime=GetTickCount();
    return 1;
}