Dell PowerConnect 8024 User's Guide - Page 443

• Client Ifc Mismatch - The number of DHCP messages that are dropped based on the source MAC address and client hardware address verification. • DHCP Server Msgs Received - The number of server messages that are dropped on an untrusted port. Viewing DHCP Snooping Statistics With CLI Commands For information about the CLI commands that perform this function, refer to the following chapter in the CLI Reference Guide: • DHCP Snooping Commands The following table summarizes the equivalent CLI commands for this feature. Table 7-71. DHCP Snooping Statistics Commands CLI Command show ip dhcp snooping statistics clear ip dhcp snooping statistics Description Displays the DHCP snooping filtration statistics. clears all DHCP Snooping statistics. DHCP Relay When a DHCP client and server are in the same IP subnet, they can directly connect to exchange IP address requests and replies. However, having a DHCP server on each subnet can be expensive and is often impractical. Alternatively, network infrastructure devices can be used to relay packets between a DHCP client and server on different subnets. Such a device, a Layer 3 Relay agent, is generally a router that has IP interfaces on both the client and server subnets and can route between them. However, in Layer 2 switched networks, there may be one or more infrastructure devices (for example, a switch) between the client and the L3 Relay agent/DHCP server. In this instance, some of the client device information required by the L3 Relay agent may not be visible to it. In this case, an L2 Relay agent can be used to add the information that the L3 Relay Agent and DHCP server need to perform their roles in address and configuration and assignment. Before it relays DHCP requests from clients, the switch can add a Circuit ID and a Remote ID. These provide information about the circuit and port number connected to the client. This information is added as suboptions in the DHCP Option 82 packets (see sections 3.1 and 3.2 of RFC3046). The switch removes this option from packets that it relays from L3 Relay agents/DHCP servers to clients. These sub-options may be used by the DHCP server to affect how it treats the client, and also may be used by the relay agent to limit broadcast replies to the specific circuit or attachment point of the client. The Switching →DHCP Relay page provides links to the following pages: • DHCP Relay Global Configuration • DHCP Relay Interface Configuration • DHCP Relay Interface Statistics Configuring Switching Information 443