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[ScreenOS] Maximum DHCP server and Relay Agent support



Article ID: KB26670 KB Last Updated: 23 Jan 2017Version: 2.0

This article explains the maximum number of DHCP servers and Relay Agents configurable on a ScreenOS device.


ScreenOS reports 'The maximum number (8) of DHCP servers has been reached'. 

Can this number be increased?



DHCP Server:

Concepts & Examples Guide - Fundamentals [PDF] states:

A security device can support up to eight DHCP servers on any physical or VLAN interface in any zone.

This number cannot be increased on any platform or version.

DHCP Relay Agent:

Concepts & Examples Guide - Fundamentals [PDF] states:

You can configure a DHCP relay agent on one or more physical or VLAN interfaces on a security device

In other words, each physical/VLAN interface can act as a Relay Agent. For example, if there are 15 physical/VLAN interfaces configured on a device, all the 15 interfaces can be configured as DHCP Relay Agents. Unlike the DHCP server, there is no upper limit to DHCP relay agent.

Important Notes:

1. A DHCP Relay Agent and DHCP server or client functions cannot exist on the same interface.
2. One can configure up to 3 DHCP servers for each DHCP Relay Agent.
3.  DHCP server is not supported on NS5200/5400.

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