Objective is to ssh IPaddr in an array and use the consecutive IPaddr in the conf file. It should complete one full loop. See example in the comment.

looping_ips.sh

#!/usr/bin/env bash
# Objective is to ssh IPaddr in an array and use the consecutive IPaddr in the conf file.
# Something like this:
# ssh 192.168.0.1 -C "echo 192.168.0.2 >> ~/ips"
# ssh 192.168.0.2 -C "echo 192.168.0.3 >> ~/ips"
# ssh 192.168.0.3 -C "echo 192.168.0.4 >> ~/ips"
# ssh 192.168.0.4 -C "echo 192.168.0.1 >> ~/ips"

x="192.168.0.1 192.168.0.2 192.168.0.3 192.168.0.4"
arr=($(echo $x | tr " " "\n"))

len=${#arr[@]}

for (( i=0; i<${len}; i++ ));
do
    if [ $i -lt $(( $len - 1 )) ];
    then
	SSH_IP=${arr[$i]}
	CONFIG_IP=${arr[$i+1]}
    else
	SSH_IP=${arr[$i]}
	CONFIG_IP=${arr[0]}
    fi
    ssh ${SSH_IP} -C "echo ${CONFIG_IP} >> ~/ips"
done