Step 1: Blocking Connections Between Parent and Child Devices

Procedure

1. Select the first batch of devices to be upgraded (referred to hereafter as C1).
   1. Select a parent device.
   2. Select child devices.
   3. Modify the DNS record to stop sending messages to the selected devices.
2. Change the iptables on the second batch of child devices (referred to hereafter as C2).
   1. Change the iptables.
      # vi /etc/init.d/rcFirewall

      At the end of start(), add the following rules:

      iptables -I INPUT -s [parent's IP] -j REJECT

      iptables -I INPUT -s [C1's IP] -j REJECT

      iptables -I INPUT -s [parent's IP] -p tcp --sport 5432 -j ACCEPT

      iptables -I INPUT -s [parent's IP] -p tcp --dport 5432 -j ACCEPT

      iptables -I OUTPUT -d [C1's IP] -j REJECT

      iptables -I OUTPUT -d [parent's IP] -p tcp --sport 5432 -j ACCEPT
   2. Apply the added rules.
      # /etc/init.d/rcFirewall restart
3. Change the iptables on the parent device.
   1. On the parent device, add the following rule:
      iptables -I INPUT -s [C2's IP] -p tcp --sport 5432 -j ACCEPT
   2. Apply the added rules.
      # /etc/init.d/rcFirewall restart