DHCP lease problem in broadband connection

For many organizations, broadband connections to ISPs are controlled by a single network node or NIC and must first be given a DHCP leased line to properly connect to the Internet. The time for DHCP leases connected to broadband is set to different lengths, and when this length is exceeded, the leased line must be released or updated. The typical lease length is 1 days to 7 days, and the DNS server needs to be notified when an assignment or allocation change occurs. Assigns a leased line to a NIC based on the MAC address.

Some ISPs will provide some of the longer leased lines together, while other shorter leased lines will be placed together. If you already have a connected firewall, and your longer leased line has expired, and you may find that when you first update the firewall, it may not find a long leased line, or even update the command without a successful update. The DHCP address in the firewall is "blocked" and requires an entire system reboot to properly update.

In this case, it may take several iterations to successfully find a new leased line. If you use the Microsoft ISA Server at this point, you may find that performing ipconfig/renew after Ipconfig/release still does not work. After that, you can only enable and disable NICs in the ISA Server in the Network Connections folder, get a new leased line, or reboot the server.

This problem can occur in many cable modem settings. I guess this is because the original broadband network design assumes that computers connected to the network will be shut down every night. With 24x7 connectivity, people want to connect to a device or server that can serve multiple systems. For security reasons, there is a good reason to have a system dedicated to frequent updates of leased lines. One solution is to choose a time at night to shut down your connected server for a few hours when the network traffic is low. You can also write a script to disable/enable your firewall's NIC.