When using SSH connection inside while Bash loop, there is need to redirect SSH input to /dev/null, as SSH reads standard input by default:
#!/bin/bash
while read IP;
do
echo $IP;
ssh root@$IP -C hostname < /dev/null;
echo ""
done < ip.txt
while read IP;
do
echo $IP;
ssh root@$IP -C hostname < /dev/null;
echo ""
done < ip.txt
Contnet of ip.txt file:
192.168.0.10
192.168.0.11
192.168.0.12
192.168.0.11
192.168.0.12