Hot Downloads



The forum is in read only mode.
Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1

TOPIC: ip helper

ip helper 10 years 3 months ago #26029

I'm looking for a clear detailing of how the "ip helper" command works. Anyone out there know this command's syntax and functionality inside and out? :?:

Re: ip helper 10 years 3 months ago #26030

  • S0lo
  • S0lo's Avatar
  • Offline
  • Moderator
  • Moderator
  • Posts: 1577
  • Karma: 3
  • Thank you received: 7
As far as I know, you use it to let the router work as a DHCP agent. forwarding all DHCP broadcasts to a DHCP server at another sub-net.

The following is what appears in ciscopedia:

ip helper-address address

no ip helper-address address

Syntax Description:
address Destination broadcast or host address to be used when forwarding UDP broadcasts. There can be more than one helper address per interface.

Command Description:
To have the Cisco IOS software forward User Datagram Protocol (UDP) broadcasts, including BOOTP, received on an interface, use the ip helper-address interface configuration command. To disable the forwarding of broadcast packets to specific addresses, use the no form of this command.

Router(config-if)#ip helper-address

Off to a good start 10 years 3 months ago #26031

I try in any thread I start to not just get an answer for myself, but to make my thread a go-to source of information for people who are interested in learning more or trying to tackle a problem that involves what I'm discussing in the future.

That said, it appears we're off to a good start. Anyone else care to throw their hat in the ring with their own explanation? How about an explanation in more clear terms than Cisco offers.

Re: ip helper 10 years 3 months ago #26120

In my terms, the ip-helper command will take a broadcast packet and sent it out unicast to a specific computer/device like a dhcp server.

I normally use the ip-helper command to forward the DHCP broadcasts to a server-based DHCP server.

The ip-helper command also sends other types of packets.
  • Page:
  • 1
Time to create page: 0.149 seconds


Cisco Routers

  • SSL WebVPN
  • Securing Routers
  • Policy Based Routing
  • Router on-a-Stick

VPN Security

  • Understand DMVPN
  • GRE/IPSec Configuration
  • Site-to-Site IPSec VPN
  • IPSec Modes

Cisco Help

  • VPN Client Windows 8
  • VPN Client Windows 7
  • CCP Display Problem
  • Cisco Support App.

Windows 2012

  • New Features
  • Licensing
  • Hyper-V / VDI
  • Install Hyper-V


  • File Permissions
  • Webmin
  • Groups - Users
  • Samba Setup