Using the default command to configure prefix advertisement content (example)

The table below lists the global unicast addresses configured on a VLAN, with original and updated settings configured using the default command.

Address or prefix

Interface

Original lifetime & autoconfig

Updated lifetime & autoconfig

Advertise on VLAN 100?

2001:db8:0:f::f1/64

VLAN 100

15 days

14 days

Auto: Yes

Set in the following example.

30 days

25 days

Auto: No(

Changed in the following example.

Yes

2001:db8:0:b::b1/64

VLAN 100

2001:db8:0:c::c1/64

VLAN 100

2001:db8:0:d::d1/64

VLAN 100

2001:db8:0:a::/64

Off-Link

12/31/2010 at 00:00:01

12/20/2010 at 00:00:01

Auto: Yes

not updated

Using the default command to configure and update prefix advertisements

Switch(config)# vlan 100
Switch(vlan–100)# ipv6 address 2001:db8:0:f::f1/64
Switch(vlan–100)# ipv6 address 2001:db8:0:b::b1/641
Switch(vlan–100)# ipv6 address 2001:db8:0:c::c1/64
Switch(vlan–100)# ipv6 nd ra prefix default 1296000 12096002
Switch(vlan–100)# show ipv6 nd ra prefix vlan 100

 IPv6 Neighbor Discovery Prefix Information

 VLAN Name : VLAN1003

   IPv6 Prefix        : Default
   Valid Lifetime     : 15 days
   Preferred Lifetime : 14 days
   On–link Flag       : On
   Autonomous Flag    : On
   Advertise Flag     : On

Switch(vlan–100)# ipv6 address 2001:db8:0:d::d1/644
Switch(vlan–100)# ipv6 nd ra prefix 2001:db8:0:d::/64 infinite no–autoconfig
Switch(vlan–100)# ipv6 nd ra prefix 2001:db8:0:a::/64 at 12/31/2010 00:00:01 12/20/2010 00:00:01 off–link5
Switch(vlan–100)# show ipv6 nd ra prefix vlan 100

 IPv6 Neighbor Discovery Prefix Information

 VLAN Name : VLAN100

   IPv6 Prefix        : Default6
   Valid Lifetime     : 15 days
   Preferred Lifetime : 14 days
   On–link Flag       : On
   Autonomous Flag    : On
   Advertise Flag     : On

   IPv6 Prefix        : 2001:db8:0:a::/647
   Valid Lifetime     : 12/31/2010 00:00:01
   Preferred Lifetime : 12/20/2010 00:00:01
   On–link Flag       : Off
   Autonomous Flag    : On
   Advertise Flag     : On

   IPv6 Prefix        : 2001:db8:0:d::/648
   Valid Lifetime     : Infinite
   Preferred Lifetime : Infinite
   On–link Flag       : On
   Autonomous Flag    : Off
   Advertise Flag     : On

Switch(vlan–100)# ipv6 nd ra prefix default 2592000 2160000 no–autoconfig9
Switch(vlan–100)# show ipv6 nd ra prefix vlan 100

 IPv6 Neighbor Discovery Prefix Information

 VLAN Name : VLAN100

   IPv6 Prefix        : Default10
   Valid Lifetime     : 30 days
   Preferred Lifetime : 25 days
   On–link Flag       : On
   Autonomous Flag    : Off
   Advertise Flag     : On

   IPv6 Prefix        : 2001:db8:0:a::/6411
   Valid Lifetime     : 12/31/2010 00:00:01
   Preferred Lifetime : 12/20/2010 00:00:01
   On–link Flag       : Off
   Autonomous Flag    : On
   Advertise Flag     : On

   IPv6 Prefix        : 2001:db8:0:d::/6412
   Valid Lifetime     : Infinite
   Preferred Lifetime : Infinite
   On–link Flag       : On
   Autonomous Flag    : Off
   Advertise Flag     : On

1 Global unicast addresses configured on VLAN 100

2 To enable advertising prefixes of global unicast addresses configured on the VLAN, the default command sets default lifetime, prefix link status (on or off-link), autoconfiguration (Autonomous Flag) status (on or off), and advertisement setting (on or off).
NOTE:

Applies only to prefixes in global unicast addresses configured on the VLAN and not uniquely configured by the prefix command.

3 To enable advertising prefixes of global unicast addresses configured on the VLAN, the default command sets default lifetime, prefix link status (on or off-link), autoconfiguration (Autonomous Flag) status (on or off), and advertisement setting (on or off).

4 Show command displays default prefix mode settings for global unicast addresses configured on VLAN 100

5 New global unicast address configured on the VLAN. Followed by command to assign unique lifetime and autoconfig setting in the advertisements for this prefix. Link flag and Advertise flag omitted from the command and therefore set to "On" by default.

6 Off-link prefix designated with unique lifetime. Autoconfig (Autonomous) flag and Advertise flag omitted from the command and therefore set to "On" default

7 Show command displays default advertisement settings for prefixes of global unicast addresses configured on VLAN 100

8 Show command displays unique advertisement settings for 2001:db8:0:a::/64 also configured on VLAN 100

9 Show command displays unique advertisement settings for 2001:db8:0:d::/64 identified as an off-link prefix

10 For prefixes configured on the VLAN and not specifically addressed by a prefix command, default changes the default lifetime and the autoconfig setting in advertisements for these prefixes. On-Link flag and Advertise flag omitted from the command and therefore set to "On" by default

11 Show command displays changes in default prefix mode settings for global unicast addresses configured on VLAN 100

12 No change for the on-link prefix specifically configured by a prefix command, and the off-link prefix that is also configured for advertisement on the VLAN