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
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).
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