Cisco Systems 3130 Manual Do Utilizador
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Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter 39 Configuring IPv6 Unicast Routing
Understanding IPv6
A value of 137 in the ICMP packet header Type field identifies an IPv6 neighbor redirect message. The
switch supports ICMPv6 redirect (RFC 2463). Routers send neighbor-redirect messages to inform hosts
of better first-hop nodes on the path to a destination. A router does not update its routing tables after
receiving a neighbor-redirect message and hosts do not originate neighbor-redirect messages.
switch supports ICMPv6 redirect (RFC 2463). Routers send neighbor-redirect messages to inform hosts
of better first-hop nodes on the path to a destination. A router does not update its routing tables after
receiving a neighbor-redirect message and hosts do not originate neighbor-redirect messages.
Neighbor discovery throttling ensures that the switch CPU is not unnecessarily burdened while it is in
the process of obtaining the next hop forwarding information to route an IPv6 packet. The switch
performs a drop in hardware of any additional IPv6 packets whose next hop is the same neighbor the
CPU is actively resolving. Performing this drop avoids adding further load on the CPU and results in a
more efficient use of the switch CPU in an IPv6 routed environment.
the process of obtaining the next hop forwarding information to route an IPv6 packet. The switch
performs a drop in hardware of any additional IPv6 packets whose next hop is the same neighbor the
CPU is actively resolving. Performing this drop avoids adding further load on the CPU and results in a
more efficient use of the switch CPU in an IPv6 routed environment.
IPv6 Applications
The switch has IPv6 support for these applications:
•
Ping, traceroute, Telnet, TFTP, and FTP
•
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 with Cisco IOS, see the “Managing Cisco IOS
Applications over IPv6” chapter in the Cisco IOS IPv6 Configuration Library at this URL:
Applications over IPv6” chapter in the Cisco IOS IPv6 Configuration Library at this URL:
Dual IPv4 and IPv6 Protocol Stacks
One technique for transitioning to IPv6 is by using dual IPv4 and IPv6 protocol stacks. Using dual stacks
enables gradual, one-by-one upgrades to applications running on nodes. Applications that are upgraded
to IPv6 use the IPv6 protocol stack, and applications that are not upgraded and support only IPv4 can
coexist with upgraded applications on the same node. New and upgraded applications can use both IPv4
and IPv6 protocol stacks.
enables gradual, one-by-one upgrades to applications running on nodes. Applications that are upgraded
to IPv6 use the IPv6 protocol stack, and applications that are not upgraded and support only IPv4 can
coexist with upgraded applications on the same node. New and upgraded applications can use both IPv4
and IPv6 protocol stacks.
The Cisco IOS software supports the dual IPv4 and IPv6 protocol stack technique. When both IPv4 and
IPv6 routing are enabled and an interface is configured with both an IPv4 and IPv6 address, the interface
forwards both IPv4 and IPv6 traffic.
IPv6 routing are enabled and an interface is configured with both an IPv4 and IPv6 address, the interface
forwards both IPv4 and IPv6 traffic.
Figure 39-1 shows a router forwarding both IPv4 and IPv6 traffic through the same interface, based on
the IP packet and destination addresses.
the IP packet and destination addresses.
Figure 39-1
Dual IPv4 and IPv6 Support on an Interface
201786
3ffe:yyyy::1
10.1.1.1
IPv6
IPv4