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Cisco Switch - IP Helper command

Posted on 2016-09-16
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Last Modified: 2016-10-09
I have 2 Core Cisco 3650 switches and 5 Access Cisco 3560 switches.
I have IP Helper set up on the Core Switches to allow VLAN access to the DHCP Server.
The Core and Access Switches are connected via uplink trunk ports.
Do I also need to create IP Helper on the Access switches?
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Question by:fsaiexpert
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max_the_king earned 1004 total points (awarded by participants)
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Hi,
i believe you do not need to set ip helper address on access switches.
When a PC broadcasts for a DHCP server on a VLAN, the  Switched Virtual Interface of that VLAN will hear and relay it to your DHCP server.
hope this helps
max
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by:fsaiexpert
ID: 41801533
The Core Switch is Layer 3 and the Access Switch are Layer 2.
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by:max_the_king
max_the_king earned 1004 total points (awarded by participants)
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it doesn't matter. Layer 3 core switch will do the trick. You can configure an ip interface on access vlan2 switch, the uplink trunk on accss switch will go through the core switch, which will do the trick.
max
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by:Bryant Schaper
Bryant Schaper earned 332 total points (awarded by participants)
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Layer 3 switch on the vlan, or router.
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by:Pete Long
Pete Long earned 332 total points (awarded by participants)
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IP helpers are set where the IP address is set, If you have set the default gateway for that particular network on a routed port, you set it there, if not and the gateway for that network segment is an SVI on a VLAN you set it there (on the VLAN).

Cisco IOS – DHCP Helper (DHCP Relay) – IP-Helper Setup

Pete
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by:Craig Beck
Craig Beck earned 332 total points (awarded by participants)
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IP helpers are only set at layer-3 devices.  Layer-2 devices don't do IP routing, so they're not where you configure layer-3 functions.
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by:Craig Beck
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