Ipv6 and switch stacks – Dell POWEREDGE M1000E User Manual
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Cisco Catalyst Blade Switch 3130 and 3032 for Dell Software Configuration Guide
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Chapter 39 Configuring IPv6 Unicast Routing
Understanding IPv6
•
The switch cannot forward SNAP-encapsulated IPv6 packets.
Note
There is a similar limitation for IPv4 SNAP-encapsulated packets, but the packets are
dropped at the switch and are not forwarded.
•
The switch routes IPv6-to-IPv4 and IPv4-to-IPv6 packets in hardware, but the switch cannot be an
IPv6-to-IPv4 or IPv4-to-IPv6 tunnel endpoint.
•
Bridged IPv6 packets with hop-by-hop extension headers are forwarded in software. In IPv4, these
packets are routed in software, but bridged in hardware.
•
In addition to the normal SPAN and RSPAN limitations defined in the software configuration guide,
these limitations are specific to IPv6 packets:
–
When you send RSPAN IPv6-routed packets, the source MAC address in the SPAN output
packet can be incorrect.
–
When you send RSPAN IPv6-routed packets, the destination MAC address can be incorrect.
Normal traffic is not affected.
•
The switch cannot apply QoS classification or policy-based routing on source-routed IPv6 packets
in hardware.
•
The switch cannot generate ICMPv6
Packet Too Big
messages for multicast packets.
IPv6 and Switch Stacks
The switch supports IPv6 forwarding across the stack and IPv6 host functionality on the stack master.
The stack master runs the IPv6 unicast routing protocols and computes the routing tables. Using
distributed CEF (dCEF), the stack master downloads the routing table to the stack member switches.
They receive the tables and create hardware IPv6 routes for forwarding. The stack master also runs all
IPv6 applications.
Note
To route IPv6 packets in a stack, all switches in the stack must be running the IP services feature set.
If a new switch becomes the stack master, it recomputes the IPv6 routing tables and distributes them to
the member switches. While the new stack master is being elected and is resetting, the switch stack does
not forward IPv6 packets. The stack MAC address changes, which also changes the IPv6 address. When
you specify the stack IPv6 address with an extended unique 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. See the
“Configuring IPv6 Addressing and Enabling IPv6 Host Functions or Routing”
.
If you configure the persistent MAC address feature on the stack and the stack master changes, the stack
MAC address does not change for approximately 4 minutes. For more information, see the