Sdm Templates - Cisco 3750G - Catalyst Integrated Wireless LAN Controller Configuration Manual

Understanding IPv6
If a new switch becomes the stack master, the new master recomputes the IPv6 routing tables and
distributes them to the member switches. While the new stack master is elected and is resetting, the
switch stack does not forward IPv6 packets. If a new switch becomes the stack master, the stack MAC
address also changes. When the IPv6 address of the stack is specified with an extended universal
identifier (EUI) by using the ipv6 address ipv6-prefix/prefix length eui-64 interface configuration
command, the address is based on the interface MAC address, and changing the MAC address changes
the IPv6 address. See the
page
If you configure the persistent MAC address feature on the stack and the stack master changes, the stack
Note
MAC address does not change for approximately four minutes. If the previous stack master rejoins the
stack as a member switch during that time period, the stack MAC address remains the MAC address of
the previous stack master. See the
Chapter 5, "Managing Switch Stacks."
These are the functions of IPv6 stack master and members:
•
•
With IPv4 unicast routing, if the stack detects that the stack master is down and elects one of the stack
members to be the new stack master, except for a momentary interruption, the hardware continues to
forward packets with no protocols active. With IPv6, the switch does not continue forwarding packets.
On election of a new stack master, the stack might need up to 60 seconds to recover all routes and resume
forwarding traffic.
IPv6 host functionality is supported on the stack master, and all IPv6 applications run on the stack
master.

SDM Templates

Most Catalyst 3750 switches have one TCAM to store unicast routes, MAC addresses, ACLs, and other
features. To allocate TCAM resources for different usages, the switch SDM templates prioritize system
resources to optimize support for certain features. You select the template that best suits the switch
environment by entering the sdm prefer global configuration command. For more information about
SDM templates, see
Catalyst 3750 Switch Software Configuration Guide
36-8
"Configuring IPv6 Addressing and Enabling IPv6 Routing" section on
36-11.
Stack master:
runs IPv6 routing protocols
–
generates routing tables
–
distributes CEFv6 routing tables to stack members that use dCEFv6
–
runs IPv6 host functionality and IPv6 applications
–
Stack member (must be running the advanced IP services image):
receives CEFv6 routing tables from the stack master
–
– programs the routes into hardware
IPv6 packets are routed in hardware across the stack provided the packet does not have
Note
exceptions (IPv6Options) and the switches in the stack have not run out of hardware
resources.
– flushes the CEFv6 tables on master re-election
Chapter 8, "Configuring SDM Templates."
"Enabling Persistent MAC Address" section on page 5-19
Chapter 36 Configuring IPv6 Unicast Routing
in
OL-8550-02