IPv6

IP version 6 (IPv6) is a routing protocol which succeeds IPv4. With the expansion of the Internet and databases IPv6 addresses consist of 128 bits whose purpose is to allow networks to include a significantly higher number of nodes by increasing the pool of available unique IP addresses. IPv6 packets alleviate overhead and allow for future customizability.

Textual representations of IPv6 addresses consist of 128 bits made up from eight 16-bit hexadecimal numbers separated by colons. IPv6 addresses may be abbreviated as follows:

  • You may omit leading zeros in each 16-bit sequence

  • You may replace an entire sequence with a double colon if it equals zero

For example, these addresses represent the same IPv6 address:

  • af23:0000:0000:0000:1284:037d:35ce:2401

  • af23:0:0:0:1284:37d:35ce:2401

  • af23::1284:37d:35ce:2401

IPv6 addresses typically denote a 64-bit network prefix and a 64-bit host address.

The following are the features IPv6 is supported on:

  • Static Routes

  • ECMP

  • Neighbor Discovery

  • BGP

  • BFD for BGP (IPv6), and Static Routes

  • DHCPv6 Relay

Neighbor Discovery (ND) decides relationships between neighbors and replaces ARP, ICMP, and ICMP redirect in IPv4.

Five kinds of ICMPv6 packets are defined by ND:

  • Neighbor advertisement

  • Router advertisement

  • Neighbor solicitation

  • Router solicitation

  • Redirect

ND checks whether a neighboring node’s address has changed, whether the neighbor is still reachable, and also resolves the address of the neighbor which a packet is being forwarded to. ND is also useful for network nodes for discovering other nodes and performing basic link-layer configuration.

IPv6_Network.png

To configure Router1:

  1. Enable IP routing. Run:

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    switch (config)# ip routing

  2. Enable forwarding IPv6 unicast packets. Run:

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    switch (config)# ipv6 routing

  3. Configure the VLAN interfaces. Run:

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    switch (config)# interface vlan 10 switch (config interface vlan 10) # exit switch (config)# interface vlan 30 switch (config interface vlan 30) # exit switch (config)# interface vlan 50 switch (config interface vlan 50) # exit

  4. Enable IPv6 on the VLAN interfaces. Run:

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    switch (config)# interface vlan 10 ipv6 enable switch (config)# interface vlan 30 ipv6 enable switch (config)# interface vlan 50 ipv6 enable

  5. Configure IPv6 addresses for each one of the VLAN interfaces. Run:

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    switch (config)# interface vlan 10 ipv6 address 2101:db01::1 /64 switch (config)# interface vlan 30 ipv6 address 2103:db01::2 /64 switch (config)# interface vlan 50 ipv6 address 2105:db01::1 /64

  6. Configure IPv6 unicast on port 2. Run:

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    switch (config)# ipv6 route 2002:db01:: /64 2101:db01::2

  7. Configure IPv6 unicast on port 8. Run:

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    switch (config)# ipv6 route 2002:db01:: /64 2105:db01::2

To configure Router2:

  1. Disable prefix mode on the CLI. Run:

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    switch (config)# no cli default prefix-mode enable

  2. Enable the VLANs on the system. Run:

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    switch (config)# vlan 10 switch (config vlan 10) # exit switch (config)# vlan 20 switch (config vlan 20) # exit switch (config)# vlan 50 switch (config vlan 50) # exit

  3. Configure the switch ports to accept the VLANs of which they are part only. Run:

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    switch (config)# interface ethernet 1/1 switchport access vlan 10 // port2 switch (config)# interface ethernet 1/2 switchport access vlan 50 // port8 switch (config)# interface ethernet 1/36 switchport access vlan 20 // port5

  4. Disable spanning tree. Run:

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    switch (config)# no spanning-tree

  5. Enable forwarding IPv6 unicast packets. Run:

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    switch (config)# ipv6 routing

  6. Configure the VLAN interfaces. Run:

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    switch (config)# interface vlan 10 switch (config interface vlan 10) # exit switch (config)# interface vlan 20 switch (config interface vlan 20) # exit switch (config)# interface vlan 50 switch (config interface vlan 50) # exit

  7. Configure IPv6 addresses for each one of the VLAN interfaces. Run:

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    switch (config)# interface vlan 10 ipv6 address 2101:db01::2 /64 switch (config)# interface vlan 20 ipv6 address 2102:db01::1 /64 switch (config)# interface vlan 50 ipv6 address 2105:db01::2 /64

  8. Configure IPv6 unicast on port 1. Run:

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    switch (config)# ipv6 route 2103:db01:: /64 2101:db01::1

  9. Configure IPv6 unicast on port 7. Run:

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    switch (config)# ipv6 route 2103:db01:: /64 2105:db01::1

Ping neighbor to verify IPv6 configuration:

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switch (config)# ping6 2101:db01::2 PING 2101:db01::2(2101:db01::2) 56 data bytes 64 bytes from 2101:db01::2: icmp_seq=1 ttl=64 time=0.371 ms 64 bytes from 2101:db01::2: icmp_seq=2 ttl=64 time=0.620 ms 64 bytes from 2101:db01::2: icmp_seq=3 ttl=64 time=0.192 ms 64 bytes from 2101:db01::2: icmp_seq=4 ttl=64 time=0.277 ms 64 bytes from 2101:db01::2: icmp_seq=5 ttl=64 time=0.231 ms

ipv6 enable

ipv6 enable
no ipv6 enable

Assigns automatic link-local IPv6 address to the interface.
The no form of the command de-assigns that automatic local address and disables IPv6 if no static IPv6 address has been assigned to the interface.

Syntax Description

N/A

Default

Unassigned

Configuration Mode

config interface vlan
config interface loopback
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated notes and command description

Example

switch (config vlan 10) # ipv6 enable

Related Commands

Notes

Assigning an IPv6 address to an interface also enables IPv6 processing on the interface.

ipv6 address

ipv6 address <ipv6-address> /<length>
no ipv6 address [<ipv6-address> [/<length>]]

Enables IPv6 processing and assigns an IPv6 address to the interface.
The no form of the command removes the specified IPv6 address. If no address is specified, then all addresses of the interface are removed.

Syntax Description

ipv6-address

IPv6 address

length

Mask length for the associated address space
Range: 1-128
The mask length may be configured without a space (i.e. <ipv6-address>/<length>)

Default

N/A

Configuration Mode

config interface vlan
config interface loopback
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated syntax description and example output

Example

switch (config vlan 10) # ipv6 address 2001::1 /120
switch (config vlan 10) # ipv6 address 2001::1/120

Related Commands

Notes

An interface may have up to 16 IPv6 address assignments

ipv6 nd managed-config-flag

ipv6 nd managed-config-flag
no ipv6 nd managed-config-flag

Sets the managed address configuration flag in IPv6 router advertisements.
The no form of the command restores the default setting.

Syntax Description

N/A

Default

Managed address configuration flag is not set

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated configuration mode

Example

switch (config vlan 10) # ipv6 nd managed-config-flag

Related Commands

Notes

ipv6 nd ns-interval

ipv6 nd ns-interval <period>
no ipv6 nd ns-interval

Configures the interval between IPv6 neighbor solicitation (NS) transmissions.
The no form of the command restores the default value.

Syntax Description

period

Time in milliseconds
Range: 1000-4294967295

Default

1000

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated configuration mode

Example

switch (config vlan 10) # ipv6 nd ns-interval 1500

Related Commands

Notes

ipv6 nd other-config-flag

ipv6 nd other-config-flag
no ipv6 nd other-config-flag

Indicates that other configuration information is available via DHCPv6.
The no form of the command removes the other configuration flag.

Syntax Description

N/A

Default

Not set

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated configuration mode

Example

switch (config vlan 10) # ipv6 nd other-config-flag

Related Commands

Notes

ipv6 nd prefix

ipv6 nd prefix <ipv6-address> /<length> [no-autoconfig] [no-onlink] [valid-time {<time> | infinite}] [preferred-time {<time> | infinite}]
ipv6 nd prefix <prefix> no-advertise
no ipv6 nd prefix <prefix>

Configures inclusion for router advertisements (RAs) for neighbor.
The no form of the command removes the corresponding IPv6 nd prefix.

Syntax Description

ipv6-address

IPv6 address

length

Prefix length for the associated address space
Range: 1-128

no-advertise

Prevents advertising of the specified default prefix

valid-time

Time in seconds
Range: 0-4294967295

preferred-time

Time in seconds
Range: 0-4294967295

no-autoconfig

Indicates that the prefix cannot be used for stateless address configuration

no-onlink

Indicates that the prefix cannot be used for on-link determination

Default

valid-time: 2592000 seconds
preferred-time: 604800 seconds
no-autoconfig: Reset, autoconfig enabled
no-onlink: Reset, on-link determination is enabled

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated syntax description, configuration mode and default values

Example

switch (config vlan 10) # ipv6 nd prefix 2001::1 /120

Related Commands

Notes

  • Valid time must be larger than preferred time

  • By default, the router advertises all configured sunbnets on the interface

ipv6 nd ra dns-servers lifetime

ipv6 nd ra dns-servers lifetime {<time> | infinite}
no ipv6 nd ra dns-servers lifetime

Advertises a lifetime of a Recursive DNS Server (RDNSS).
The no form of the command resets the lifetime value to default.

Syntax Description

time

Possible values:

  • 0 –RDNSS address can no longer be used

  • 1-4294967295 in seconds

infinite

A value of all one bits (0xffffffff) and “infinite” represents infinity

Default

If no lifetime period is configured on the interface, the default value is 1.5 times the Router Advertisement (RA) interval set by the command “ipv6 nd ra interval”

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command and syntax description, configuration mode and default values

Example

switch (config vlan 10) # ipv6 nd ra dns-servers lifetime infinite

Related Commands

Notes

  • Using the RDNSS and DNSSL options, an IPv6 host can perform IPv6 address network configuration and DNS information simultaneously, without using DHCPv6 for the DNS configuration

  • A lifetime value set for an individual RDNSS overrides this value

  • The lifetime value is the maximum amount of time after a route advertisement packet is sent that the RDNSS referenced in the packet may be used for name resolution

ipv6 nd ra dns-server

ipv6 nd ra dns-server <ipv6 address> [lifetime [<time> | infinite]]
no ipv6 nd ra dns-server [<ipv6 address>]

Configures the IPv6 address of a Recursive DNS Server (RDNSS) to include in the neighbor-discovery router advertisements (RAs).
The no form of the command removes the RDNSS from the configuration.

Syntax Description

ipv6 address

IPv6 address of RDNSS

lifetime

Maximum lifetime value for the specified RDNSS entry. Possible values:

  • 0 –RDNSS address can no longer be used

  • 1-4294967295 in seconds

infinite

A value of all one bits (0xffffffff) and “infinite” represents infinity

Default

If no lifetime period is configured on the interface, the default value is 1.5 times the Router Advertisement (RA) interval set by the command “ipv6 nd ra interval”

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command, example and syntax description, configuration mode and default values

Example

switch (config vlan 10) # ipv6 nd ra dns-server 2001::1 lifetime infinite

Related Commands

Notes

  • Including RDNSS information in RAs provides DNS server configuration for connected IPv6 hosts without requiring DHCPv6

  • Multiple servers can be configured on the interface by using the command repeatedly

  • A lifetime value for the RDNSS can optionally be specified with this command, and overrides any default value configured for the interface using the ipv6 nd ra dns-servers lifetime command

ipv6 nd ra dns-suffixes lifetime

ipv6 nd ra dns-suffixes <domain-name> lifetime {<time> | infinite}
no ipv6 nd ra dns-suffixes <domain-name> lifetime

Advertises a lifetime of a DNS Search List (DNSSL).
Using RDNSS and DNSSL options, an IPv6 host can perform IPv6 address network configuration and DNS information simultaneously, without using DHCPv6 for the DNS configuration.
The no form of the command resets the lifetime value to its default.

Syntax Description

time

Possible values:

  • 0 –RDNSS address can no longer be used

  • 1-4294967295 in seconds

infinite

A value of all one bits (0xffffffff) and “infinite” represents infinity

Default

If no lifetime period is configured on the interface, the default value is 1.5 times the Router Advertisement (RA) interval set by the command “ipv6 nd ra interval”

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command, example and syntax description, configuration mode and default values

Example

switch (config vlan 10) # ipv6 nd ra dns-suffix domain.com lifetime infinite

Related Commands

Notes

The DNSSL contains the domain names of DNS suffixes for IPv6 hosts to append to short, unqualified domain names for DNS queries

ipv6 nd ra dns-suffix

ipv6 nd ra dns-suffix <domain-name> [lifetime {<time> | infinite}]
no ipv6 nd ra dns-suffix [<domain-name>]

Creates a DNS search list (DNSSL) to include in the neighbor-discovery Router Advertisements (RAs).
The no form of the command removes the DNSSL from the configuration.

Syntax Description

domain-name

Domain suffix for IPv6 hosts to append to short unqualified domain names for DNS queries
The suffix must contain only alphanumeric characters, “.” (periods), “-” (hyphens), and must begin and end with an alphanumeric character

lifetime

Maximum lifetime value for the specified DNSSL entry

time

Possible values:

  • 0 –DNSSL must not be used for name resolution

  • 1-4294967295 in seconds

infinite

A value of all one bits (0xffffffff) and “infinite” represents infinity

Default

If no lifetime period is configured on the interface, the default value is 1.5 times the Router Advertisement (RA) interval set by the command “ipv6 nd ra interval”

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command, example and syntax description, configuration mode and default values

Role

admin

Example

switch (config vlan 10) # ipv6 nd ra dns-suffix domain.com lifetime infinite

Related Commands

Notes

  • The DNSSL contains the domain names of DNS suffixes for IPv6 hosts to append to short, unqualified domain names for DNS queries

  • Multiple DNS domain names can be added to the DNSSL by reusing the command

  • A lifetime value for the DNSSL can optionally be specified with this command which overrides any default value configured for the interface using the command “ipv6 nd ra dns-suffixes lifetime”

ipv6 nd ra hop-limit

ipv6 nd ra hop-limit <limit>
no ipv6 nd ra hop-limit

Sets a suggested hop-limit value to be included in route advertisement (RA) packets.
The no form of the command resets the parameter to its default value.

Syntax Description

limit

The hop-limit value to be included by attached hosts in outgoing packets.

  • 0 –unspecified (by this router)

  • 1-255 –number of hops

Default

Limit value is 64

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated configuration modes

Example

switch (config vlan 10) # ipv6 nd ra hop-limit 70

Related Commands

Notes

ipv6 nd ra interval max-period

ipv6 nd ra interval max-period <time> [min-period <time>]
no ipv6 nd ra interval

Configures the interval between IPv6 router advertisement (RA) transmissions.
The no form of the command resets the parameter to its default value.

Syntax Description

time

Maximum interval between successive IPv6 router advertisement transmissions
Range: 4-1800 seconds

min-period

Minimum interval between successive IPv6 router advertisement transmissions:

  • Default is used if no parameter is given

  • 4-1800

Default

max-period: 600 seconds
min-period: See Note

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated syntax description, configuration modes and notes

Example

switch (config vlan 10) # ipv6 nd ra interval max-period 600

Related Commands

Notes

  • The min-period must be 0.33 * <max-period> if <max-period> is >= 9 seconds; otherwise, the default is Router Advertisement Interval

  • The parameter min-period must be no less than 3 seconds and no greater than 0.75*max-period

ipv6 nd ra lifetime

ipv6 nd ra lifetime <time>
no ipv6 nd ra lifetime

Router lifetime is associated with a router’s usefulness as default route, it does not apply to information contained in other message fields or options. Options that need time limits for their information include their own lifetime fields.
The no form of the command resets the parameter to its default value.

Syntax Description

time

The router lifetime specifies the period that the router can be considered as a default router by RA recipients in seconds.

  • 0 –the router should not be considered a default router on this interface

  • 1-9000 –lifetime period advertised in RAs should not be less than the max router advertisement interval

Default

3*<router advertisement interval>

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Added support for IPv6

Example

switch (config vlan 10) # ipv6 nd ra lifetime 300

Related Commands

Notes

ipv6 nd ra mtu suppress

ipv6 nd ra mtu suppress
no ipv6 nd ra mtu suppress

Suppresses advertisement (RA) MTU option sent to router.
MTU option ensures all nodes on a link use the same MTU value.
The no form of the command restores the MTU option to enabled.

Syntax Description

N/A

Default

Suppressed

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command Syntax and configuration mode

Example

switch (config vlan 10) # ipv6 nd ra mtu suppress

Related Commands

Notes

If not suppressed, MTU of the interface is advertised.

ipv6 nd ra suppress

ipv6 nd ra suppress [all]
no ipv6 nd ra suppress

Suppresses periodic and solicited IPv6 router advertisement (RA) transmissions.
The no form of the command restores the transmission of RAs.

Syntax Description

all

Configures the switch to suppress all RAs, including those responding to a router solicitation.

Default

Only unsolicited RAs transmitted periodically are suppressed

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command syntax and configuration mode

Example

switch (config vlan 10) # ipv6 nd ra suppress all

Related Commands

Notes

ipv6 nd reachable-time

ipv6 nd reachable-time <time>
no ipv6 nd reachable-time

Sets the time period the switch includes in the reachable time field of outgoing advertisements (RAs).
The no form of the command resets the parameter to its default value.

Syntax Description

time

In milliseconds; the reachable time defines the period that a node assumes a neighbor is reachable after having received a reachability confirmation. Values:

  • 0 –unspecified by router

  • 1 –3600000 the period that a node assumes a neighbor is reachable

Default

0 (unspecified)

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command syntax, configuration mode and notes

Example

switch (config vlan 10) # ipv6 nd reachable-time 30000

Related Commands

Notes

RAs that advertise zero seconds indicate that the router does not specify a reachable time

ipv6 nd router-preference

ipv6 nd router-preference {high | medium | low}
no ipv6 nd router-preference

Sets the value the switch enters in the default router preference (DRP) field of router advertisements (RAs) it sends.
The no form of the command resets the parameter to its default value.

Syntax Description

N/A

Default

Medium

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated configuration modes

Example

switch (config vlan 10) # ipv6 nd router-preference high

Related Commands

Notes

  • IPv6 hosts maintain a default router list from which to select a router for traffic to offlink destinations. The router’s address is then saved in the destination cache. The neighbor discovery protocol (NDP) prefers routers that are reachable or probably reachable over routers whose reachability is unknown or suspect. For reachable or probably reachable routers, NDP can either select the same router every time or cycle through the router list. DRP values specify a host’s preferred router.

  • If router lifetime is zero, preference value must be medium

ipv6 nd retrans-timer

ipv6 nd retrans-timer <time>
no ipv6 nd retrans-timer

Advertises the time between consecutive neighbor solicitation (NS) messages.
The no form of the command resets the parameter to its default value.

Syntax Description

time

In milliseconds; the time between retransmitted neighbor solicitation messages. Possible values:

  • 0 –unspecified

  • Range –1000-4294967295

Default

0 (unspecified)

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated command syntax, configuration mode and example output

Example

switch (config vlan 10) # ipv6 nd retrans-timer 1000

Related Commands

Notes

ipv6 nd redirects

ipv6 nd redirects
no ipv6 nd redirects

Enables sending ICMPv6 redirect messages.
The no form of the command disables sending ICMPv6 redirect messages.

Syntax Description

N/A

Default

Disabled

Configuration Mode

config interface vlan

History

3.4.1100

Example

switch (config interface vlan 10) # ipv6 nd redirects

Related Commands

Notes

ipv6 nd dad attempts

ipv6 nd dad attempts <number>
no ipv6 nd dad attempts

Sets the number of consecutive neighbor solicitation messages sent for duplicate address detection (DAD) validation.
The no form of the command resets the value to its default.

Syntax Description

number

Number of attempts:

  • 0 –DAD is not performed

  • Range: 1-1000

Default

1

Configuration Mode

config interface vlan
config interface ethernet configured as a router port interface
config interface port-channel configured as a router port interface

History

3.4.1100

3.6.4110

Updated configuration mode

Role

admin

Example

switch (config vlan 10) # ipv6 nd dad attempts 10

Related Commands

Notes

clear ipv6 neighbors

clear ipv6 neighbors {ethernet <slot> /<port> | port-channel <port-channel> | vlan <vlan-id>} [<ipv6-addr>]

Removes the specified dynamic IPv6 neighbor discovery cache entries.

Syntax Description

ethernet

Ethernet port (<slot>/<port>)

vlan

VLAN interface

ipv6-addr

IPv6 address

Default

N/A

Configuration Mode

config

History

3.4.1100

3.6.4110

Updated command

Example

switch (config) # clear ipv6 neighbors ethernet 1/4

Related Commands

Notes

  • Commands that do not specify an IPv6 address remove all dynamic entries for the listed interface

  • Commands that do not specify an interface remove all dynamic entries

ipv6 route

  • General route:
    ipv6 route [vrf <vrf-name>] {<ipv6-prefix> | <ipv6-address> /<length>} <next-hop-ipv6-address> [<distance>]

  • Local route:
    ipv6 route [vrf <vrf-name>] {<ipv6-prefix> | <ipv6-address> /<length>}

    ipv6 route
    [<distance>]

  • Drop route:
    ipv6 route [vrf <vrf-name>] {<ipv6-prefix> | <ipv6-address> /<length>} null0 [<distance>]

  • Delete route(s):
    no ipv6 route [vrf <vrf-name>] {<ipv6-prefix> | <ipv6-address> /<length>} [<next-hop-ipv6-address>]

Creates an IPv6 static route.
The no form of the command deletes static routes.

Syntax Description

ipv6-address

IPv6 address

ipv6-prefix

IPv6 address + mask length without space (e.g. a1:a2::33/64)

length

Prefix length for the associated address space
Range: 1-128

next-hop-ipv6-address

IPv6 address of the next-hop

distance

Administrative distance assigned to route.
Options include:

  • No parameter –route is assigned a default administrative distance of 1

  • 1-255 –the administrative distance assigned to route

null0

Creates a black hole route with action DROP

Default

No distance parameter indicated: Administrative distance of 1

Configuration Mode

config

History

3.4.1100

3.6.4110

Updated command

3.9.1600

Removed ethernet, port-channel, and vlan options

Example

switch (config) # ipv6 route 3003:db01:: /64 2001:db01::1

Related Commands

Notes

  • Static routes have a default administrative distance of 1

  • Assigning a higher administrative distance to a static route configures it to be overridden by dynamic routing data

  • Multiple routes which are configured to the same destination with the same administrative distance comprise an Equal Cost Multi-Path (ECMP) route

  • A no command not including a source deletes all statements to the destination

  • Route with distance value 255 is not inserted to the forwarding table

ipv6 routing

ipv6 routing
no ipv6 routing

Enables forwarding IPv6 unicast packets.
The no form of the command disables IPv6 unicast routing.

Syntax Description

N/A

Default

Disabled

Configuration Mode

config

History

3.4.1100

Example

switch (config) # ipv6 routing

Related Commands

Notes

When routing is enabled, the switch attempts to deliver inbound packets to destination addresses by forwarding them to interfaces or next hop addresses specified by the IPv6 routing table

ipv6 routing disable-discard-counter

ipv6 routing disable-discard-counter
no ipv6 routing disable-discard-counter

Disables router discard counters.
The no form of the command restores discard counters advancing.

Syntax Description

N/A

Default

Disabled

Configuration Mode

config

History

3.9.2100

Example

switch (config) # ipv6 routing disable-discard-counter

Related Commands

Notes

A reboot is required for the feature to take effect.

show ipv6 interfaces

show ipv6 interfaces [{{ethernet <port> | port-channel <port-channel> | vlan <vlan-id>}}| brief]

Displays the status of specified routed interfaces that are configured for IPv6.

Syntax Description

ethernet <port>

Displays output pertaining to the specified Ethernet interface

port-channel <port-channel>

Displays output pertaining to the specified LAG interface

vlan <vlan-id>

Displays output pertaining to the specified VLAN interface

brief

Shows basic IPv6 information regarding all IPv6 interfaces

Default

N/A

Configuration Mode

Any command mode

History

3.6.4110

Example

switch (config) # show ipv6 interface
Vlan10 is Enabled ,  line protocol is UP
IPv6 : Enabled
Link-local address : fe80::f652:14ff:fe2d:9808
Global Unicast Addresses :
2001:db01::2 /64
Joined Group Addresses :
ff02::1
ff02::2
ff02::1:ff2d:9808
MTU : 1500 bytes
ICMP error messages limited to every milliseconds : 100
ICMP redirects : enabled
ND DAD : enabled
Number of DAD attempts : 1
ND reachable time (milliseconds) : 30000
ND advertised retransmit interval (milliseconds) : 0
ND router advertisements maximum interval (seconds) : 600
ND router advertisements minimum interval (seconds) : 198
ND router advertisements managed configuration flag : unset
ND router advertisements other configuration flag : unset
ND solicited router advertisement : suppressed
ND router advertisements lifetime (seconds) : 1800
ND advertised default router preference : medium
ND router advertisements hop-limit : 64

Related Commands

Notes

show ipv6 interfaces brief

show ipv6 interfaces [<type> <id>] brief

Displays basic IPv6 information regarding all IPv6 interfaces

Syntax Description

<type> <id>

Specifies the interface for which to display data

Default

N/A

Configuration Mode

Any command mode

History

3.6.4110

3.6.8008

Updated Example

Example

 switch (config) # show ipv6 interface brief
-------------------------------------------------------------------------------------------------------------
Interface Address/Mask Primary Address-state Admin-state Oper-state MTU VRF
-------------------------------------------------------------------------------------------------------------
mgmt0 fe80::784e/64 valid Enabled Up 1500 default
Eth1/1 2001::1/64 primary valid Enabled Down 1500 default
Eth1/1 2002::1/64 valid

Related Commands

Notes

show interfaces null0

show interfaces null0 [vrf <vrf-name>]

Displays blackhole route byte and packet counters.

Syntax Description

N/A

Default

N/A

Configuration Mode

Any command mode

History

3.6.4110

Example

switch (config) # show interfaces null0
10 packets
740 bytes

Related Commands

Notes

show ipv6 neighbors

show ipv6 neighbors [{ethernet <port> | port-channel <port-channel> | vlan <vlan-id>} | <ipv6 address> | summary]

Displays IPv6 neighbor discovery (ND) cache information.

Syntax Description

ethernet <port>

Displays output pertaining to the specified Ethernet interface.

vlan <vlan-id>

Displays output pertaining to the specified VLAN interface.

ipv6 address

IPv6 address of individual neighbor

Default

N/A

Configuration Mode

Any command mode

History

3.4.1100

3.6.4110

Updated command syntax and Example

Example

switch (config) # show ipv6 neighbors
IPv6 Address               MAC Address        State       Interf
------------------------ ----------------- ---------- ------
2001:db01::1 f4:52:14:2d:98:88 Reachable vlan10

Related Commands

Notes

show ipv6 route

show ipv6 route [vrf <vrf-name] {[<ipv6-address> <ipv6-address>/<length> [longer-prefixes]] [connected | bgp | static]}

Displays IPv6 neighbor discovery (ND) cache information.

Syntax Description

ipv6-addr

Filters routes by IPv6 address or prefix

longer-prefixes

Displays output for longer prefix entries

connected

Displays entries for routes to networks directly connected to the switch

static

Displays entries added through CLI commands

summary

Displays the current contents of the IPv6 routing table in summary format

Default

N/A

Configuration Mode

Any command mode

History

3.4.1100

3.6.4110

Updated Example

3.6.8008

Updated Example

Example

switch (config) # show ipv6 route

Flags:
F: Failed to install in H/W
B: BFD protected
i: BFD session initializing
x: protecting BFD session failed

VRF Name default:
---------------------------------------------------------------------------
Destination Flag Gateway Interface Source AD/M
---------------------------------------------------------------------------
fe80::/64 :: mgmt0 direct 256/256
default :: mgmt0 direct 1/1

Related Commands

Note

© Copyright 2023, NVIDIA. Last updated on Sep 8, 2023.