An IP helper address is used to forward DHCP broadcasts to where they need to go. Through this process, you can use a single server for managing IP subnets on a network and checking client and device leases.
When an IP helper address is enabled, traffic for UDP ports are automatically forwarded to the specified address. Subnets not on their own DHCP server will be assigned an ip address helper command.
Using IP Helper Addresses
With an IP helper address enabled, routers can accept broadcast requests for UDP services, which are then forwarded as a unicast to a specific address. A helper address must be configured on an interface when forwarding a client UDP application broadcast request when the client and server are on different networks. Routers can also forward these requests to specific networks or subnetworks. This process is one that is typically used by C/C++ programmers.
Configuring IP Helper Addresses
It is important to note that anyone making these changes should have a working knowledge of Windows networking and TCP/IP concepts. In short, this isn’t something that should be done by beginners. In Windows, there are a few different ways to turn on/turn off IP helper.
The first method is through Services.msc. In the Start menu, search folders or files for Services.msc. Locate the IP helper option and select it to open. The option to turn on or turn off helper addresses is located under the General tab. Save changes and close.
Regedit can also be used to toggle IP helper on or off. This is done by accessing the User Account Control panel, and editing the registry. Warning: editing the registry can create serious problems with your system if done incorrectly. Anyone that chooses to use this method should be aware of the potential risks before making any registry changes.
The command prompt can also be used in Windows. This involves changing the startup type and inputting a command to start or stop the service.
IP helper can also be accessed through MSconfig similar to changing the option through Services.msc.
Final Notes
While an IP helper can offer benefits to your network, it’s important to remember that this should only be handled by network administrators or someone with technical know-how. These advanced options should be done with caution to prevent problems with your system.
Do you have more questions about IP helper? What has been your experience with IP helper? Comment below and let us know!
Sources
- http://www.dummies.com/programming/networking/cisco/ip-helper-address-utilization/
- http://www.ciscopress.com/articles/article.asp?p=330807&seqNum=9
- http://www.brocade.com/content/html/en/configuration-guide/FI_08030_L3/GUID-9B9DCF22-7E92-4E92-BF1F-C14B2DF0C734.html
- https://msdn.microsoft.com/en-us/library/windows/desktop/aa366073(v=vs.85).aspx.aspx)