Dell Configuration Guide for the S4048–ON System 9.14.2.4

Example configuration of interface level DHCP relay source IPv4 or IPv6 interface

Following are the steps to configure interface specific source IPv4 or IPv6 configuration for DHCP relay. The below example shows when the DHCP relay uses the interface specific configuration and global source interface configuration depending on the configuration.

1. Configuring L3 interface with IPv4 or IPv6 address.

   Following are the steps to configure a L3 interface (loopback) with IPv4 and IPv6 address in INTERFACE MODE.

   Dell(conf)# interface loopback 2
   Dell(conf-if-lo-1)# ip vrf forwarding vrf1
   Dell(conf-if-lo-1)# ip address 2.2.2.2/32
   Dell(conf-if-lo-1)# ipv6 address 2::2/128
   Dell(conf-if-lo-1)# no shutdown
   Dell(conf)# interface loopback 3
   Dell(conf-if-lo-1)# ip vrf forwarding vrf2
   Dell(conf-if-lo-1)# ip address 3.3.3.3/32
   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