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What is DHCP snooping on a switch?

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What is DHCP snooping on a switch?

DHCP Snooping is a layer 2 security technology incorporated into the operating system of a capable network switch that drops DHCP traffic determined to be unacceptable. DHCP Snooping prevents unauthorized (rogue) DHCP servers offering IP addresses to DHCP clients.

How does IP DHCP snooping work?

The DHCP snooping feature dynamically builds and maintains the database using information extracted from intercepted DHCP messages. The database contains an entry for each untrusted host with a leased IP address if the host is associated with a VLAN that has DHCP snooping enabled.

Where is DHCP snooping implemented and why?

DHCP Snooping is a Layer 2 security switch feature which blocks unauthorized (rogue) DHCP servers from distributing IP addresses to DHCP clients. In fact Cisco was the first vendor to implement DHCP Snooping as a security feature in its network switches and other vendors have since then followed with similar features.

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How do I enable DHCP snooping?

The minimum configuration steps for the DHCP snooping feature are as follows:

  1. Define and configure the DHCP server.
  2. Enable DHCP snooping on at least one VLAN.
  3. Ensure that DHCP server is connected through a trusted interface.
  4. Configure the DHCP snooping database agent.
  5. Enable DHCP snooping globally.

Should DHCP snooping be enabled?

DHCP snooping is disabled by default and the trust setting of ports is untrusted by default. DHCP snooping must be enabled on the client and the DHCP server VLANs. Enter global configuration mode by issuing the configure terminal command. Enable DHCP snooping on a VLAN.

What is DHCP snooping in Mcq?

Explanation: DHCP snooping is a security feature that is used in OS of a network in the layer 2. This technology prevents unauthorized DHCP servers offering IP addresses to DHCP clients.

How do I add snooping to DHCP?

DHCP snooping must be enabled on the client and the DHCP server VLANs.

  1. Enter global configuration mode by issuing the configure terminal command.
  2. Enable DHCP snooping on a VLAN.
  3. Change the trust setting of the ports that are connected to the DHCP server to trusted at the interface configuration level.
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What is DHCP snooping binding?

DHCP snooping binding table is used to identify and filter untrusted DHCP messages from the network. DHCP snooping binding table includes the client MAC address, IP address, DHCP lease time, binding type, VLAN number, and interface information on untrusted switch ports.

What is DHCP snooping limit?

On the Port tab, configure options for DHCP snooping. Rate limit (pkts/sec): Specifies the number of DHCP packets received per second on the interface. If the number exceeds the specified value, system will drop the excessive DHCP packets. The value range is 0 to 10000.

What is dhdhcp snooping and how does it work?

DHCP Snooping is a layer 2 security technology incorporated into the operating system of a capable network switch that drops DHCP traffic determined to be unacceptable. DHCP Snooping prevents unauthorized (rogue) DHCP servers offering IP addresses to DHCP clients. The DHCP Snooping feature performs the following activities:

What is the default VLAN for DHCP snooping?

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VLAN 1 is the default VLAN on Cisco switches. By default, all ports belong to this VLAN. Since DHCP snooping works on VLANs and we did not create any VLAN in our example, we implemented DHCP snooping on the default VLAN using the fourth command.

How many DHCP bindings can the DHCP snooping database store?

When configuring the DHCP snooping database agent, note the following information: † With releases earlier than Release 12.2(18)SXF5, the DHCP snooping database stores a maximum of 512 bindings. If the database attempts to add more than 512 DHCP bindings, all bindings are removed from the database.

How to configure DHCP snooping rate limit on a trusted interface?

Generally, the rate limit is applied to untrusted interfaces. But if required, you can also configure it on a trusted interface. To configure DHCP snooping rate limit on an interface, use the ‘ip dhcp snooping limit rate [number]’ command in interface configuration mode of the interface.