Dhcp Relay - Dell PowerConnect 8024 User Manual

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
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port.
Viewing DHCP Snooping Statistics With CLI Commands
For information about the CLI commands that perform this function, refer to the following chapter in
CLI Reference Guide
the
• 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

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
:
Description
Displays the DHCP snooping filtration statistics.
clears all DHCP Snooping statistics.
Configuring Switching Information
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