Cisco Catalyst 3560-X Series, Руководство по настройке программного обеспечения

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Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-25303-03
Chapter 1 Configuring IPv6 Unicast Routing
Understanding IPv6
The following restrictions apply:
• When IPv6 source guard is enabled on a switchport, NDP or DHCP snooping must be enabled on
the interface to which the switchport belongs. Otherwise all data traffic from this port will be
blocked.
•
An IPv6 source guard policy cannot be attached to a VLAN.
• IPv6 source guard is not supported on EtherChannels.
For information about configuring IPv6 access lists, see the " Implementing Traffic Filters and Firewalls
for IPv6 Security " chapter of the Cisco IOS IPv6 Configuration Library on Cisco.com.
Default Router Preference
The switch supports IPv6 default router preference (DRP), an extension in router advertisement
messages. DRP improves the ability of a host to select an appropriate router, especially when the host is
multihomed and the routers are on different links. The switch does not support the Route Information
Option in RFC 4191.
An IPv6 host maintains a default router list from which it selects a router for traffic to offlink
destinations. The selected router for a destination is then cached in the destination cache. NDP for IPv6
specifies that routers that are reachable or probably reachable are preferred 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. By using DRP, you can configure an IPv6 host
to prefer one router over another, provided both are reachable or probably reachable.
For more information about DRP for IPv6, see the “Implementing IPv6 Addresses and Basic
Connectivity” chapter in the
Cisco IOS IPv6 Configuration Library on Cisco.com.
IPv6 Stateless Autoconfiguration and Duplicate Address Detection
The switch uses stateless autoconfiguration to manage link, subnet, and site addressing changes, such as
management of host and mobile IP addresses. A host autonomously configures its own link-local
address, and booting nodes send router solicitations to request router advertisements for configuring
interfaces.
For more information about autoconfiguration and duplicate address detection, see the “Implementing
IPv6 Addressing and Basic Connectivity” chapter of
Cisco IOS IPv6 Configuration Library on
Cisco.com.
IPv6 Applications
The switch has IPv6 support for these applications:
•
Ping, traceroute, Telnet, and TFTP
• Secure Shell (SSH) over an IPv6 transport
•
HTTP server access over IPv6 transport
•
DNS resolver for AAAA over IPv4 transport
•
Cisco Discovery Protocol (CDP) support for IPv6 addresses
For more information about managing these applications, see the “Managing Cisco IOS Applications
over IPv6” chapter and the “Implementing IPv6 Addressing and Basic Connectivity” chapter in the
Cisco IOS IPv6 Configuration Library on Cisco.com.