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run the &quot;ip dhcp snooping&quot; command on your switch and see if it accepts it.<br />
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if it does you should also use &quot;ip dhcp snooping vlan &lt;number&gt;&quot; and &quot;ip dhcp snooping trust&quot;<br />
on trusted interfaces - except if you want to ban DHCP altogether.
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run the "ip dhcp snooping" command on your switch and see if it accepts it.

if it does you should also use "ip dhcp snooping vlan <number>" and "ip dhcp snooping trust"
on trusted interfaces - except if you want to ban DHCP altogether.

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That's the info I needed. &nbsp;Thanks!
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I have manage the Ethernet network for an apartment building that consists of a 50Mb circuit, 7204VXR router, and five Catalyst 3548XL switches. &nbsp;This building is full of users that love to connect wireless routers &quot;backwards&quot; into the LAN and backfeed DHCP into the network and screw everything up. &nbsp;Is it possible to configure the 3548 switches to suppress this behavior? &nbsp;If not, what is the cheapest switch model (on the refurb market) to gain this functionality. &nbsp;Thanks!
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I have manage the Ethernet network for an apartment building that consists of a 50Mb circuit, 7204VXR router, and five Catalyst 3548XL switches.  This building is full of users that love to connect wireless routers "backwards" into the LAN and backfeed DHCP into the network and screw everything up.  Is it possible to configure the 3548 switches to suppress this behavior?  If not, what is the cheapest switch model (on the refurb market) to gain this functionality.  Thanks!

DHCP Snooping on Catalyst 3548XL Switches

A switch is a device that filters and forwards packets of data between LAN segments. Switches operate at the data link layer or the network layer of the Open Systems Interconnection (OSI) Reference Model and therefore support any packet protocol. LANs that use switches to join segments are called switched LANs or, in the case of Ethernet networks, switched Ethernet LANs. A hub is a connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports; when a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

Switches / Hubs

Networking hardware includes the physical devices facilitating the use of a computer network. Typically, networking hardware includes gateways, routers, network bridges, modems, wireless access points, networking cables, line drivers, switches, hubs, and repeaters. But it also includes hybrid network devices such as multilayer switches, protocol converters, bridge routers, proxy servers, firewalls, network address translators, multiplexers, network interface controllers, wireless network interface controllers, ISDN terminal adapters and other related hardware.