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Dell(conf-if-lo-1)# ipv6 address 3::3/128
Dell(conf-if-lo-1)# no shutdown
2. Creating L3 interfaces with the DHCP helper configuration.
Following are the steps to configure IPv4 or IPv6 interfaces with the DHCP helper configuration. The below example shows
two VLAN interfaces (Vlan 2 and 4), DHCP helper (100.0.0.1 and 100::1) for the respective VLANs and the DHCP relay
source IPv4 and IPv6 configuration, and two different loopback interfaces (loopback 2 and 3). DHCP relay forwards packets
using the loopback 2 interface with IPv4 and IPv6 addresses ((2.2.2.2/32 and 2::2/128) from Vlan 2. The same way, the
relay uses IPv4 and IPv6 addresses (3.3.3.3/32 and 3::3/128) of loopback 3 interface from Vlan 3.
Dell(conf)# interface Vlan 2
Dell(conf-if-vl-2)# ip vrf forwarding vrf1
Dell(conf-if-vl-2)# ip address 2.0.0.1/24
Dell(conf-if-vl-2)# ipv6 address 2::1/64
Dell(conf-if-vl-2)# tagged fortyGigE 0/0
Dell(conf-if-vl-2)# ip helper-address vrf vrf1 100.0.0.1
Dell(conf-if-vl-2)# ipv6 helper-address vrf vrf1 100::1
Dell(conf-if-vl-2)# ip dhcp relay source-interface loopback 2
Dell(conf-if-vl-2)# ipv6 dhcp relay source-interface loopback 2
Dell(conf)# interface Vlan 4
Dell(conf-if-vl-4)# ip vrf forwarding vrf1
Dell(conf-if-vl-4)# ip address 4.0.0.1/24
Dell(conf-if-vl-4)# ipv6 address 4::1/64
Dell(conf-if-vl-4)# tagged fortyGigE 0/4
Dell(conf-if-vl-4)# ip helper-address vrf vrf1 100.0.0.1
Dell(conf-if-vl-4)# ipv6 helper-address vrf vrf1 100::1
Dell(conf-if-vl-4)# ip dhcp relay source-interface loopback 3
Dell(conf-if-vl-4)# ipv6 dhcp relay source-interface loopback 3
3. In the below configuration, the DHCP relay source interface is not configured in the VLAN interface. So, the DHCP relay
uses the configured global DHCP relay source interface to forward the packets from the DHCP client to server.
Dell(conf)# interface Vlan 5
Dell(conf-if-vl-4)# ip vrf forwarding vrf1
Dell(conf-if-vl-4)# ip address 4.0.0.1/24
Dell(conf-if-vl-4)# ipv6 address 4::1/64
Dell(conf-if-vl-4)# tagged TenGigE 1/4
Dell(conf-if-vl-4)# ip helper-address vrf vrf1 100.0.0.1
Dell(conf-if-vl-4)# ipv6 helper-address vrf vrf1 100::1
Configure the System for User Port Stacking (Option
230)
Set the stacking-option variable to provide stack-port detail on the DHCP server when you set the DHCP offer. A stack can be
formed when the units are connected.
Option 230 is the option for user port stacking. Use it to create up to eight stack groups. Define the configuration parameters
on the DHCP server for each chassis based on the chassis MAC address. Configure the following parameters:
● unit number
● priority
● stack group ID
The received stacking configuration is always applied on the master stack unit.
option #230 "unit-number:3#priority:2#stack-group:14"
Configure Secure DHCP
DHCP as defined by RFC 2131 provides no authentication or security mechanisms. Secure DHCP is a suite of features that
protects networks that use dynamic address allocation from spoofing and attacks.
● Option 82
● DHCP Snooping
Dynamic Host Configuration Protocol (DHCP)
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