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Cisco Catalyst Blade Switch 3120 for HP Software Configuration Guide
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Chapter 39 Configuring IPv6 Unicast Routing
Understanding IPv6
For complete syntax and usage information on these commands, see the Cisco IOS command references.
Unsupported IPv6 Unicast Routing Features
The switch does not support these IPv6 features in this release:
•
IPv6 policy-based routing
•
IPv6 virtual private network (VPN) routing and forwarding (VRF) table support
•
Support for these IPv6 routing protocols: Multiprotocol Border Gateway Protocol (BGP),
Intermediate System-to-Intermediate System (IS-IS) routing, Enhanced Interior Gateway Routing
Protocol (EIGRP)
•
Simple Network Management Protocol (SNMP) over IPv6 transport
•
IPv6 Hot Standby Router Protocol (HSRP)
•
DHCPv6
•
IPv6 packets destined to site-local addresses
•
Tunneling protocols, such as IPv4-to-IPv6 or IPv6-to-IPv4
•
The switch as a tunnel endpoint supporting IPv4-to-IPv6 or IPv6-to-IPv4 tunneling protocols
•
IPv6 unicast reverse-path forwarding
•
IPv6 general prefixes
Limitations
Because IPv6 is implemented in hardware in the switch, some limitations occur due to the use of IPv6
compressed addresses in the hardware memory. These hardware limitations result in some loss of
functionality and limits some features.
These are feature limitations.
•
Load-balancing using equal cost and unequal cost routes is not supported for IPv6 host routes or for
IPv6 routes with a mask greater than 64.
•
The switch cannot correctly forward SNAP-encapsulated IPv6 packets. These packets are corrupted
before being forwarded (bridged or routed) and reach the network as corrupted packets.
Note
There is a similar limitation for IPv4 SNAP-encapsulated packets, but the packets are
dropped at the switch and are not forwarded as corrupted packets.
•
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.