We're Sorry, Full Content Access is for Members Only...

If you like to keep on reading, Become a Member Now! Here is Why:

  • Learn any CCNA, CCNP and CCIE R&S Topic. Explained As Simple As Possible.
  • Try for Just $1. The Best Dollar You've Ever Spent on Your Cisco Career!
  • Full Access to our 618 Lessons. More Lessons Added Every Week!
  • Content created by Rene Molenaar (CCIE #41726)


390 New Members signed up the last 30 days!


100% Satisfaction Guaranteed!
You may cancel your monthly membership at any time.
No Questions Asked!

Tags: , ,

Forum Replies

  1. Thanks for your kind words :slight_smile: The e-books are available through Clickbank and the hardcopies through Amazon.com, you can use a creditcard or paypal. If those are not accepted then we can always look for another online payment method that you can use…

  2. Hi rené, i have another question: How can we use DHCP Relay when we have multiple subinterfaces for multiple VLANs on the fastethernet 0/0 ( ie: fastethernet 0/0.1, 0/0.2 and so on) of the middle router knowing that each VLAN has its own addressing scheme ??


  3. I just found this and i think it solves the problem: while configuring the DHCP router for multiple VLANs, we must specify the default-router (it’s the gateway adress of each VLAN) from which the request is comming (as shown below). This way the DHCP router assigns IPs from the particular pools of each VLAN.

    (config)# ip dhcp pool VLAN1
    (dhcp-config)# network
    (dhcp-config)# default-router
    (dhcp-config)# exit

  4. Hi Rene,

    Will the ip helper-address always be the address of the interface on the the DHCP server that connects to the DHCP relay?

  5. Hi Shree,

    Nothing will change. The router that is configured for DHCP relay will create these unicast packets. Other routers only have to route these packets to the DHCP server, that’s it. Here’s a packet capture of these unicast packets btw:

    DHCP Relay Unicast Packets


34 more replies! Ask a question or join the discussion by visiting our Community Forum