Administrator Guide

Layer 2 Switching Commands 325
DHCP Client Commands
Dell Networking N1500/N2000/N3000/N4000 Series Switches
Dell Networking switches support an embedded DHCP client. Any IP
interface can use DHCP to obtain an IP address. The DHCP client can run
on multiple interfaces simultaneously.
For IPv4, an IP interface can either use manually configured addresses or be
enabled for DHCP. The options are mutually exclusive. When the operator
enables DHCPv4 on an IP interface, all manually configured IP addresses on
that interface are removed from the running configuration. When the
operator configures an IP address, the system automatically releases any IPv4
address assigned by a DHCP server and disables DHCPv4 on the interface.
For IPv6, DHCP can coexist with configured addresses. The operator may
enable DHCPv6 and configure IPv6 addresses on the same interface. Only a
single in-band interface can be configured as a DHCPv6 client.
DHCP is disabled by default on in-band interfaces except for the N2000 and
N1500 Series switches.
The DHCP client retains an IP address even if the IP interface goes down.
The client does not attempt to renew its IP address until the lease expires,
regardless of changes in link state.
The operator may renew or release an IP address at any time using the
dhcp
l2relay (Global Configuration)
and renew dhcp CLI commands (or web or
SNMP equivalents).
When an IPv6 address is leased from a DHCP server, the address has a mask
length of 128. A local route for the network is only installed if the router
receives and accepts IPv6 router advertisements on the interface. Because
router advertisements are not accepted on a routing interface, a leased IPv6
address on a routing interface is not necessarily useful.
The Dell Networking DHCP/BOOTP client processes the following
information from the DHCP server:
• Host IP Address
• Host Netmask
• Next Server Address
• TFTP Server Name (siaddr)
2CSNXXX_SWUM204.book Page 325 Monday, January 25, 2016 1:25 PM