recursion in bash

#!/bin/bash
ip_up(){
        server_ip=$1
        trials=$2
        max_trials=2
        status=0
        echo "server ip is: $server_ip, trial $trials" >&2
        if ping -i 1 -c 3 "$server_ip" &> /dev/null
        then
            status=1
        else
            status=0
            while ((  "$trials" < "$max_trials" )); do
                echo -e "$server_ip is down: Trial $trials, checking again after 1 sec" >&2
                sleep 1
                ((trials++))
                ip_up "$server_ip" "$trials"
            done
        fi
        echo "$status"
}

status=$(ip_up "$ip" 1)
echo -e "the returned status is: ====$status====\n"

<<'COMMENT'
//results

 $ ./check_servers.sh
checking box1(173.36.232.6)
server ip is: 173.36.232.6, trial 1
173.36.232.6 is down: Trial 1, checking again after 1 sec
server ip is: 173.36.232.6, trial 2
the returned status is: ====0
0====

./check_servers.sh: line 41: [: 0
0: integer expression expected
Sat Jun  4 15:16:11 EAT 2016 box2 (173.36.232.7) is UP
checking box2 (173.36.232.7)
server ip is: 173.36.232.7, trial 1
the returned status is: ====1====

COMMENT