Cisco IP Helper-Address

Posted on 2012-08-16
Last Modified: 2012-09-03
On a Cisco 3750x and ME3600's, do you need to put an ip helper-address on the layer 2 switches ofrjust the layer 3 switches?
Question by:bsfoote
    LVL 17

    Accepted Solution

    Normally, you put an IP helper on a L3 device in order to allow for L2-protocols like DHCP to contact other devices on other networks ... if you need to use a device from a separate  L3 subnet, you should have a router in place ... put the helper in there and you should be fine ...
    LVL 11

    Expert Comment

    Garry-G is correct.

    If for example;

    you have a L3 core with connected L2 access switches with multiple vlans 2-10 and a dhcp server on

    a vlan conf could like like:

    conf t
    int vlan 2
    ip address
    ip helper-address

    Author Comment

    Both of you have covered my current setup, is there somewhere in VMware besides the IP and binding on the DHCP server?
    LVL 17

    Expert Comment

    VMWare has interfaces that are usually bound to certain vlans and physical ports. Make sure you're actually in the right vlan...

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