14-114 Dual Stack ConfigurationWhen configuring dual stack, go to these sections for information you are interested in:z Dual Stack Overviewz Configuring Dual StackDual Stack OverviewDual stack is the most direct approach to making IPv6 nodes compatible with IPv4 nodes. The bestway for an IPv6 node to be compatible with an IPv4 node is to maintain a complete IPv4 stack. Anetwork node that supports both IPv4 and IPv6 is called a dual stack node. A dual stack nodeconfigured with an IPv4 address and an IPv6 address can have both IPv4 and IPv6 packetstransmitted.For an upper layer application supporting both IPv4 and IPv6, either TCP or UDP can be selected atthe transport layer, while IPv6 stack is preferred at the network layer.Figure 14-1 illustrates the IPv4/IPv6 dual stack in relation to the IPv4 stack.Figure 14-1 IPv4/IPv6 dual stack in relation to IPv4 stack (on Ethernet)IPv4 application IPv4/IPv6 applicationTCP UDP TCP UDPIPv4 IPv4 IPv6Ethernet EthernetProtocol ID:0x0800Protocol ID:0x0800Protocol ID:0x86DDIPv4 stack Dual stackConfiguring Dual StackYou must enable the IPv6 packet forwarding function before dual stack. Otherwise, the device cannotforward IPv6 packets even if IPv6 addresses are configured for interfaces.Follow these steps to configure dual stack on a gateway:To do… Use the command… RemarksEnter system view system-view —Enable the IPv6 packet forwarding function ipv6RequiredDisabled bydefault.
