What is Giaddr in DHCP?

What is Giaddr in DHCP?

The DHCP server, by referring to the relay agent IP address (giaddr) in a DHCP Discover message, selects an IP address to allocate to the DHCP client from an IP pool, and sends a DHCP Offer message with the destination IP address set as the relay agent IP address2.

Should DHCP snooping be enabled?

DHCP snooping should be enabled on VLANs, after which the trust setting of ports connected to a DHCP server must be changed to trusted. DHCP packets for a VLAN with DHCP snooping enabled are inspected.

What happens when DHCP snooping is enabled?

With DHCP snooping MAC address verification enabled, DHCP snooping verifies that the source MAC address and the client hardware address match in DHCP packets that are received on untrusted ports.

What is DHCP snooping?

DHCP snooping is a security feature that acts like a firewall between untrusted hosts and trusted DHCP servers. The DHCP snooping feature performs the following activities: Validates DHCP messages received from untrusted sources and filters out invalid messages.

What is the Giaddr?

Typically, DHCP relay agents rely on the Gateway IP Address (GIADDR) field to communicate with DHCP servers. However, GIADDR is limited by its two operational functions: To inform the DHCP server about the subnet upon which the DHCP client that is requesting the IP address lease resides.

What is Option 82 in DHCP snooping?

Option 82 provides information about the network location of a DHCP client, and the DHCP server uses this information to implement IP addresses or other parameters for the client.

How do I turn off DHCP snooping?

Disabling DHCP snooping on an interface

1. Enter system view.
2. Enter interface view.
3. Disable DHCP snooping on the interface. dhcp snooping disable. By default: If you enable DHCP snooping globally or for a VLAN, DHCP snooping is enabled on all interfaces on the device or on all interfaces in the VLAN.

What is DHCP 82 Ubiquiti?

Option 82 is called the relay agent information option and is inserted by the DHCP relay agent when forwarding client-originated DHCP packets to a DHCP server. Servers recognizing the relay agent information option may use the information to implement IP address or other parameter assignment policies.

Is DHCP option 82 needed?

The routing switch can operate as a DHCP relay agent to enable communication between a client and a DHCP server on a different subnet. Without Option 82, DHCP operation modifies client IP address request packets to the extent needed to forward the packets to a DHCP server.

What is Cisco Dai?

Overview. Dynamic ARP Inspection (DAI) is a security feature in MS switches that protects networks against man-in-the-middle ARP spoofing attacks. DAI inspects Address Resolution Protocol (ARP) packets on the LAN and uses the information in the DHCP snooping table on the switch to validate ARP packets.