666 IPv6 Routing Commands
Syntax
ipv6 mtu 
mtu
no ipv6 mtu
•
mtu
 — Is the maximum transmission unit. (Range: 1280-1500)
Default Configuration
The default MTU is 1500.
Command Mode
Interface Configuration (VLAN, Tunnel, Loopback) mode
User Guidelines
This command has no user guidelines.
Example
The following example sets the maximum transmission unit (MTU) size, in bytes, of IPv6 
packets.
console(config)#interface vlan 15
console(config-if-vlan15)#ipv6 mtu 1300
ipv6 nd dad attempts
Use the ipv6 nd dad attempts command in Interface Configuration mode to set the number of 
duplicate address detection probes transmitted while doing neighbor discovery. Duplicate 
address detection verifies that an IPv6 address on an interface is unique.
Syntax
ipv6 nd dad attempts 
attempts
no ipv6 nd dad attempts
•
attempts
 — Probes transmitted. (Range: 0-600)
Default Configuration
The default value for attempts is 1.
Command Mode
Interface Configuration (VLAN, Tunnel, Loopback) mode