Concept Guide

IPv6 conguration, and two dierent 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 conguration, the DHCP relay source interface is not congured in the VLAN interface. So, the DHCP relay uses the
congured 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
Congure 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 oer. 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. Dene the conguration parameters on the DHCP
server for each chassis based on the chassis MAC address. Congure the following parameters:
• unit number
• priority
• stack group ID
The received stacking conguration is always applied on the master stack unit.
option #230 "unit-number:3#priority:2#stack-group:14"
Congure Secure DHCP
DHCP as dened 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 spoong and attacks.
• Option 82
• DHCP Snooping
• Dynamic ARP Inspection
• Source Address Validation
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Dynamic Host Conguration Protocol (DHCP)