This page allows you to configure an IPv6 interface for management access over the network or for creating an interface to multiple subnets. This switch supports both IPv4 and IPv6, and can be managed through either of these address types.
Command Usage
IPv6 includes two distinct address types - link-local unicast and global unicast. A link-local address makes the switch accessible over IPv6 for all devices attached to the same local subnet. Management traffic using this kind of address cannot be passed by any router outside of the subnet. A link-local address is easy to set up, and may be useful for simple networks or basic troubleshooting tasks. However, to connect to a larger network with multiple segments, the switch must be configured with a global unicast address.
An IPv6 global unicast or link-local address can be manually configured (using the Add IPv6 Address page), or a link-local address can be dynamically generated (using the Configure Interface page).
Use the IP > IPv6 Configuration (Configure Global) page to configure an IPv6 default gateway for the switch.
Sets the IPv6 address of the default next hop router.
If no static routes are defined, you must define a gateway if the target device is located in a different subnet.
If a routing protocol is enabled, you can still define a static route to ensure that traffic to the designated address or subnet passes through a preferred gateway.
An IPv6 default gateway can only be successfully set when a network interface that directly connects to the gateway has been configured on the switch.
An IPv6 address must be configured according to RFC 2373 "IPv6 Addressing Architecture," using 8 colon-separated 16-bit hexadecimal values. One double colon may be used in the address to indicate the appropriate number of zeros required to fill the undefined fields.
Use the IP > IPv6 Configuration (Configure Interface) page to configure general IPv6 settings for the selected VLAN, including auto-configuration of a global unicast interface address, explicit configuration of a link local interface address, the MTU size, and neighbor discovery protocol settings for duplicate address detection and the neighbor solicitation interval.
Command Usage
The switch must be configured with a link-local address. The switch¡¦s address auto-configuration function will automatically create a link-local address, as well as an IPv6 global address if router advertisements are detected on the local interface.
The option to explicitly enable IPv6 creates a link-local address, but will not generate a global IPv6 address if auto-configuration is not enabled. In this case, you can manually configure a global unicast address.
IPv6 Neighbor Discovery Protocol supersedes IPv4 Address Resolution Protocol in IPv6 networks. IPv6 nodes on the same network segment use Neighbor Discovery to discover each other's presence, to determine each other's link-layer addresses, to find routers and to maintain reachability information about the paths to active neighbors. The key parameters used to facilitate this process are the number of attempts made to verify whether or not a duplicate address exists on the same network segment, and the interval between neighbor solicitations used to verify reachability information.
Command Parameters
ID of a configured VLAN which is to be used for management access. By default, all ports on the switch are members of VLAN 1. However, the management station can be attached to a port belonging to any VLAN, as long as that VLAN has been assigned an IP address.
Enables stateless autoconfiguration of IPv6 addresses on an interface and enables IPv6 functionality on that interface. The network portion of the address is based on prefixes received in IPv6 router advertisement messages, and the host portion is automatically generated using the modified EUI-64 form of the interface identifier (i.e., the switch‘s MAC address).
If the router advertisements have the "other stateful configuration" flag set, the switch will attempt to acquire other non-address configuration information (such as a default gateway).
If auto-configuration is not selected, then an address must be manually configured using the Add Interface page described below.
Enables IPv6 on an interface. Note that when an explicit address is assigned to an interface, IPv6 is automatically enabled, and cannot be disabled until all assigned addresses have been removed. (Default: Disabled)
Disabling this parameter does not disable IPv6 for an interface that has been explicitly configured with an IPv6 address.
Sets the size of the maximum transmission unit (MTU) for IPv6 packets sent on an interface. (Range: 1280-65535 bytes; Default: 1500 bytes)
The maximum value set in this field cannot exceed the MTU of the physical interface, which is currently fixed at 1500 bytes.
IPv6 routers do not fragment IPv6 packets forwarded from other routers. However, traffic originating from an end-station connected to an IPv6 router may be fragmented.
All devices on the same physical medium must use the same MTU in order to operate correctly.
IPv6 must be enabled on an interface before the MTU can be set. If an IPv6 address has not been assigned to the switch, “N/A” is displayed in the MTU field.
The number of consecutive neighbor solicitation messages sent on an interface during duplicate address detection. (Range: 0-600, Default: 3)
Configuring a value of 0 disables duplicate address detection.
Duplicate address detection determines if a new unicast IPv6 address already exists on the network before it is assigned to an interface.
Duplicate address detection is stopped on any interface that has been suspended. While an interface is suspended, all unicast IPv6 addresses assigned to that interface are placed in a "pending" state. Duplicate address detection is automatically restarted when the interface is administratively re-activated.
An interface that is re-activated restarts duplicate address detection for all unicast IPv6 addresses on the interface. While duplicate address detection is performed on the interface's link-local address, the other IPv6 addresses remain in a "tentative" state. If no duplicate link-local address is found, duplicate address detection is started for the remaining IPv6 addresses.
If a duplicate address is detected, it is set to "duplicate" state, and a warning message is sent to the console. If a duplicate link-local address is detected, IPv6 processes are disabled on the interface. If a duplicate global unicast address is detected, it is not used. All configuration commands associated with a duplicate address remain configured while the address is in "duplicate" state.
If the link-local address for an interface is changed, duplicate address detection is performed on the new link-local address, but not for any of the IPv6 global unicast addresses already associated with the interface.
The interval between transmitting IPv6 neighbor solicitation messages on
an interface. (Range: 1000-3600000 milliseconds; Default: 1000 milliseconds
is used for neighbor discovery operations,
0 milliseconds is advertised in router advertisements.
This attribute specifies the interval between transmitting neighbor solicitation messages when resolving an address, or when probing the reachability of a neighbor. Therefore, avoid using very short intervals for normal IPv6 operations.When a non-default value is configured, the specified interval is used both for router advertisements and by the router itself.
The amount of time that a remote IPv6 node is considered reachable after some reachability confirmation event has occurred. (Range: 0-3600000 milliseconds; Default: 30000 milliseconds)
The time limit configured by this parameter allows the router to detect unavailable neighbors. During the neighbor discover process, an IPv6 node will multicast neighbor solicitation messages to search for neighbor nodes. For a neighbor node to be considered reachable, it must respond to the neighbor soliciting node with a neighbor advertisement message to become a confirmed neighbor, after which the reachable timer will be considered in effect for subsequent unicast IPv6 layer communications.
This time limit is included in all router advertisements sent out through an interface, ensuring that nodes on the same link use the same time value.
Setting the time limit to 0 means that the configured time is unspecified by this router.
When DHCPv6 is restarted, the switch may attempt to acquire an IP address prefix through stateful address autoconfiguration. If the router advertisements have the "other stateful configuration" flag set, the switch may also attempt to acquire other non-address configuration information (such as a default gateway) when DHCPv6 is restarted.
Prior to submitting a client request to a DHCPv6 server, the switch should be configured with a link-local address using the Address Autoconfig option. The state of the Managed Address Configuration flag (M flag) and Other Stateful Configuration flag (O flag) received in Router Advertisement messages will determine the information this switch should attempt to acquire from the DHCPv6 server as described below.
Both M and O flags are set to 1:
DHCPv6 is used for both address and other configuration settings.
This combination is known as DHCPv6 stateful autoconfiguration, in which a DHCPv6 server assigns stateful addresses to IPv6 hosts.
The M flag is set to 0, and the O flag is set to 1:
DHCPv6 is used only for other configuration settings.
Neighboring routers are configured to advertise non-link-local address prefixes from which IPv6 hosts derive stateless addresses.
This combination is known as DHCPv6 stateless autoconfiguration, in which a DHCPv6 server does not assign stateful addresses to IPv6 hosts, but does assign stateless configuration settings.
Use the IP > IPv6 Configuration (Add IPv6 Address) page to configure an IPv6 interface for management access over the network.
Command Usage
All IPv6 addresses must be formatted according to RFC 2373 "IPv6 Addressing Architecture," using 8 colon-separated 16-bit hexadecimal values. One double colon may be used in the address to indicate the appropriate number of zeros required to fill the undefined fields.
The switch must always be configured with a link-local address. Therefore, explicitly enabling IPv6 or manually assigning a global unicast address will also automatically generate a link-local unicast address. The prefix length for a link-local address is fixed at 64 bits, and the host portion of the default address is based on the modified EUI-64 (Extended Universal Identifier) form of the interface identifier (i.e., the physical MAC address). Alternatively, you can manually configure the link-local address by entering the full address with the network prefix FE80~FEBF.
To connect to a larger network with multiple subnets, you must configure a global unicast address. There are several alternatives to configuring this address type:
It can be manually configured by specifying the entire network prefix and prefix length, and using the EUI-64 form of the interface identifier to automatically create the low-order 64 bits in the host portion of the address.
You can also manually configure the global unicast address by entering the full address and prefix length.
You can configure multiple IPv6 global unicast addresses per interface, but only one link-local address per interface.
If a duplicate link-local address is detected on the local segment, this interface is disabled and a warning message displayed on the console. If a duplicate global unicast address is detected on the network, the address is disabled on this interface and a warning message displayed on the console.
When an explicit address is assigned to an interface, IPv6 is automatically enabled, and cannot be disabled until all assigned addresses have been removed.
Command Parameters
ID of a configured VLAN which is to be used for management access, or for creating an interface to multiple subnets. By default, all ports on the switch are members of VLAN 1. However, the management station can be attached to a port belonging to any VLAN, as long as that VLAN has been assigned an IP address.
Defines the address type configured for this interface.
Configures an IPv6 global unicast address with a full IPv6 address including the network prefix and host address bits, followed by a forward slash, and a decimal value indicating how many contiguous bits (from the left) of the address comprise the prefix (i.e., the network portion of the address).
Configures an IPv6 address for an interface using an EUI-64 interface ID in the low order 64 bits.
When using EUI-64 format for the low-order 64 bits in the host portion of the address, the value entered in the IPv6 Address field includes the network portion of the address, and the prefix length indicates how many contiguous bits (starting at the left) of the address comprise the prefix (i.e., the network portion of the address). Note that the value specified in the IPv6 Address field may include some of the high-order host bits if the specified prefix length is less than 64 bits. If the specified prefix length exceeds 64 bits, then the bits used in the network portion of the address will take precedence over the interface identifier.
IPv6 addresses are 16 bytes long, of which the bottom 8 bytes typically form a unique host identifier based on the device‘s MAC address. The EUI-64 specification is designed for devices that use an extended 8-byte MAC address. For devices that still use a 6-byte MAC address (also known as EUI-48 format), it must be converted into EUI-64 format by inverting the universal/local bit in the address and inserting the hexadecimal number FFFE between the upper and lower three bytes of the MAC address.
For example, if a device had an EUI-48 address of 28-9F-18-1C-82-35, the global/local bit must first be inverted to meet EUI-64 requirements (i.e., 1 for globally defined addresses and 0 for locally defined addresses), changing 28 to 2A. Then the two bytes FFFE are inserted between the OUI (i.e., organizationally unique identifier, or company identifier) and the rest of the address, resulting in a modified EUI-64 interface identifier of 2A-9F-18-FF-FE-1C-82-35.
This host addressing method allows the same interface identifier
to be used on multiple IP interfaces of a single device, as long
as those interfaces are attached to different subnets.
Configures an IPv6 link-local address.
The address prefix must be in the range of FE80~FEBF.
You can configure only one link-local address per interface.
The specified address replaces a link-local address that was automatically generated for the interface.
IPv6 address assigned to this interface.
Use the IP > IPv6 Configuration (Show IPv6 Address) page to display the IPv6 addresses assigned to an interface.
ID of a configured VLAN which is to be used for management access, or for creating an interface to multiple subnets. By default, all ports on the switch are members of VLAN 1. However, the management station can be attached to a port belonging to any VLAN, as long as that VLAN has been assigned an IP address.
The address type (Global, EUI-64, Link Local).
An IPv6 address assigned to this interface.
In addition to the unicast addresses assigned to an interface, a node is also required to listen to the all-nodes multicast addresses FF01::1 (interface-local scope) and FF02::1 (link-local scope)
FF01::1/16 is the transient interface-local multicast address for all attached IPv6 nodes, and FF02::1/16 is the link-local multicast address for all attached IPv6 nodes. The interface-local multicast address is only used for loopback transmission of multicast traffic. Link-local multicast addresses cover the same types as used by link-local unicast addresses, including all nodes (FF02::1), all routers (FF02::2), and solicited nodes (FF02::1:FFXX:XXXX) as described below.
A node is also required to compute and join the associated solicited-node multicast addresses for every unicast and anycast address it is assigned. IPv6 addresses that differ only in the high-order bits, e.g. due to multiple high-order prefixes associated with different aggregations, will map to the same solicited-node address, thereby reducing the number of multicast addresses a node must join. In this example, FF02::1:FF90:0/104 is the solicited-node multicast address which is formed by taking the low-order 24 bits of the address and appending those bits to the prefix.
Note that the solicited-node multicast address (link-local scope FF02) is used to resolve the MAC addresses for neighbor nodes since IPv6 does not support the broadcast method used by the Address Resolution Protocol in IPv4.
These additional addresses are displayed by the CLI using the "show ip interface" command.
Indicates if this address was automatically generated for manually configured.
Use the IP > IPv6 Configuration (Show IPv6 Neighbor Cache) page to display the IPv6 addresses detected for neighbor devices.
IPv6 address of neighbor
The time since the address was verified as reachable (in seconds). A static entry is indicated by the value “Permanent.”
Physical layer MAC address.
The following states are used for dynamic entries:
Incomplete - Address resolution is being carried out on the entry. A neighbor solicitation message has been sent to the multicast address of the target, but it has not yet returned a neighbor advertisement message.
Invalid - An invalidated mapping. Setting the state to invalid dis-associates the interface identified with this entry from the indicated mapping (RFC 4293).
Reachable - Positive confirmation was received within the last ReachableTime interval that the forward path to the neighbor was functioning. While in REACH state, the device takes no special action when sending packets.
Stale - More than the ReachableTime interval has elapsed since the last positive confirmation was received that the forward path was functioning. While in STALE state, the device takes no action until a packet is sent.
Delay - More than the ReachableTime interval has elapsed since the last positive confirmation was received that the forward path was functioning. A packet was sent within the last DELAY_FIRST_PROBE_TIME interval. If no reachability confirmation is received within this interval after entering the DELAY state, the switch will send a neighbor solicitation message and change the state to PROBE.
Probe - A reachability confirmation is actively sought by resending neighbor solicitation messages every RetransTimer interval until confirmation of reachability is received.
Unknown - Unknown state.
The following states are used for static entries:
Incomplete-The interface for this entry is down.
Reachable - The interface for this entry is up. Reachability detection is not applied to static entries in the IPv6 neighbor discovery cache.
VLAN interface from which the address was reached.
This switch provides statistics for the following IPv6, ICMPv6 and UDP traffic types:
The Internet Protocol for Version 6 addresses provides a mechanism for transmitting blocks of data (often called packets or frames) from a source to a destination, where these network devices (that is, hosts) are identified by fixed length addresses. The Internet Protocol also provides for fragmentation and reassembly of long packets, if necessary, for transmission through "small packet" networks.
Internet Control Message Protocol for Version 6 addresses is a network layer protocol that transmits message packets to report errors in processing IPv6 packets. ICMP is therefore an integral part of the Internet Protocol. ICMP messages may be used to report various situations, such as when a datagram cannot reach its destination, when the gateway does not have the buffering capacity to forward a datagram, and when the gateway can direct the host to send traffic on a shorter route. ICMP is also used by routers to feed back information about more suitable routes (that is, the next hop router) to use for a specific destination.
User Datagram Protocol provides a datagram mode of packet switched communications. It uses IP as the underlying transport mechanism, providing access to IP-like services. UDP packets are delivered just like IP packets – connection-less datagrams that may be discarded before reaching their targets. UDP is useful when TCP would be too complex, too slow, or just unnecessary.
For a detailed description of these statistics, refer to the User Manual.
Use the IP > IPv6 Configuration (Show MTU) page to display the maximum transmission unit (MTU) cache for destinations that have returned an ICMP packet-too-big message along with an acceptable MTU to this switch.
Adjusted MTU contained in the ICMP packet-too-big message returned from this destination, and now used for all traffic sent along this path.
Time since an ICMP packet-too-big message was received from this destination.
Address which sent an ICMP packet-too-big message.