Administrator Guide

● The system provides 40K dhcp binding entries that can be divided between leased addresses and excluded addresses.
By extension, the maximum number of pools you can configure depends on the subnet mask that you give to each pool. For
example, if all pools were configured for a /24 mask, the total would be 40000/253 (approximately 158). If the subnet is
increased, more pools can be configured. The maximum subnet that can be configured for a single pool is /17. The system
displays an error message for configurations that exceed the allocated memory.
● The switch supports 4K DHCP Snooping entries.
● All platforms support Dynamic ARP Inspection on 16 VLANs per system. For more information, refer to Dynamic ARP
Inspection.
NOTE: If the DHCP server is on the top of rack (ToR) and the VLTi (ICL) is down due to a failed link, when a VLT node
is rebooted in JumpStart mode, it is not able to reach the DHCP server, resulting in bare metal provisioning (BMP)
failure.
Configure the System to be a DHCP Server
A DHCP server is a network device that has been programmed to provide network configuration parameters to clients upon
request. Servers typically serve many clients, making host management much more organized and efficient.
The following table lists the key responsibilities of DHCP servers.
Table 26. DHCP Server Responsibilities
DHCP Server Responsibility Description
Address Storage and Management DHCP servers are the owners of the addresses used by DHCP
clients. The server stores the addresses and manages their
use, keeping track of which addresses have been allocated
and which are still available.
Configuration Parameter Storage and Management DHCP servers also store and maintain other parameters that
are sent to clients when requested. These parameters specify
in detail how a client is to operate.
Lease Management DHCP servers use leases to allocate addresses to clients for a
limited time. The DHCP server maintains information about
each of the leases, including lease length.
Responding To Client Requests DHCP servers respond to different types of requests from
clients, primarily, granting, renewing, and terminating leases.
Providing Administration Services DHCP servers include functionality that allows an
administrator to implement policies that govern how DHCP
performs its other tasks.
NOTE: DHCP server is not supported on VLT.
Configuring the Server for Automatic Address Allocation
Automatic address allocation is an address assignment method by which the DHCP server leases an IP address to a client from a
pool of available addresses.
An address pool is a range of IP addresses that the DHCP server may assign. The subnet number indexes the address pools.
To create an address pool, follow these steps.
1. Access the DHCP server CLI context.
CONFIGURATION mode
ip dhcp server
2. Create an address pool and give it a name.
DHCP mode
pool name
3. Specify the range of IP addresses from which the DHCP server may assign addresses.
328
Dynamic Host Configuration Protocol (DHCP)