Operation Manual – IPv6H3C S3610&S5510 Series Ethernet Switches Chapter 1 IPv6 Basics Configuration1-14Note:z After an IPv6 site-local address or aggregatable global unicast address isconfigured for an interface, a link-local address will be generated automatically. Theautomatically generated link-local address is the same as the one generated byusing the ipv6 address auto link-local command. If a link-local address ismanually assigned to an interface, this link-local address takes effect. If themanually assigned link-local address is removed, the automatically generatedlink-local address takes effect.z The manual assignment takes precedence over the automatic generation. That is, ifyou first adopt the automatic generation and then the manual assignment, themanually assigned link-local address will overwrite the automatically generated one.If you first adopt the manual assignment and then the automatic generation, theautomatically generated link-local address will not take effect and the link-localaddress of an interface is still the manually assigned one. If you delete the manuallyassigned address, the automatically generated link-local address is validated.z You need to execute the ipv6 address auto link-local command before the undoipv6 address auto link-local command. However, if an IPv6 site-local address oraggregatable global unicast address is already configured for an interface, theinterface still has a link-local address because the system automatically generatesone for the interface. If no IPv6 site-local address or aggregatable global unicastaddress is configured, the interface has no link-local address.z The manually configured global unicast address takes precedence over the oneautomatically generated. If a global unicast address has been generated on aninterface when you configure another one with the same address prefix, the latteroverwrites the previous one. After that, the overwritten global unicast address willnot be restored even if the manually configured one is removed. The global unicastaddress will be generated again based on the address prefix information in the RAmessage that the device receives for the next time.1.4 Configuring IPv6 NDP1.4.1 Configuring a Static Neighbor EntryThe IPv6 address of a neighbor node can be resolved into a link-layer addressdynamically through NS and NA messages or through a manually configured neighborentry.The device uniquely identifies a static neighbor entry according to the IPv6 address andthe layer 3 interface ID. Currently, there are two configuration methods:z Configure an IPv6 address and link-layer address for a Layer 3 interface.z Configure an IPv6 address and link-layer address for a port in a VLAN.
