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The Cisco Express Forwarding feature is Layer 3 IP switching technology for the forwarding of IPv6 packets.
To forward IPv6 traffic using Cisco Express Forwarding , you must configure forwarding of IPv6 unicast datagrams globally on the device, and you must configure an IPv6 address on an interface.
You must enable Cisco Express Forwarding for IPv4 globally on the device before enabling Cisco Express Forwarding for IPv6 globally on the device.
Nondistributed platforms do not support distributed Cisco Express Forwarding; however, some distributed platforms support both Cisco Express Forwarding and distributed Cisco Express Forwarding.
To use Unicast Reverse Path Forwarding (uRPF), enable Cisco Express Forwarding switching in the device. There is no need to configure the input interface for Cisco Express Forwarding switching. As long as Cisco Express Forwarding is running on the device, individual interfaces can be configured with other switching modes.
The following restrictions apply to nondistributed and distributed architecture platforms configured for Cisco Express Forwarding :
IPv6 packets that have global source and destination addresses are Cisco Express Forwarding-switched .
IPv6 packets that have link-local source and destination addresses are process-switched.
IPv6 packets that are tunneled within manually configured IPv6 tunnels are Cisco Express Forwarding-switched.
Cisco Express Forwarding is advanced, Layer 3 IP switching technology for the forwarding of IPv6 packets.
Each IPv6 router interface has an association to one IPv6 global FIB and one IPv6 link-local FIB (multiple interfaces can have an association to the same FIB). All IPv6 router interfaces that are attached to the same IPv6 link share the same IPv6 link-local FIB. IPv6 packets that have an IPv6 global destination address are processed by the IPv6 global FIB; however, packets that have an IPv6 global destination address and an IPv6 link-local source address are sent to the RP for process switching and scope-error handling. Packets that have a link-local source address are not forwarded off of the local link and are sent to the RP for process switching and scope-error handling.
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enable
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configure
terminal
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ipv6
cef
accounting
[non-recursive |
per-prefix |
prefix-length]
In the following example, both Cisco Express Forwarding for IPv6 and network accounting for Cisco Express Forwarding for IPv6 have been enabled globally on a nondistributed architecture device, and Cisco Express Forwarding for IPv6 has been enabled on Gigabit Ethernet interface 0/0/0. The example also shows that the forwarding of IPv6 unicast datagrams has been configured globally on the device with the ipv6 unicast-routing command, an IPv6 address has been configured on Gigabit Ethernet interface 0/0/0 with the ipv6 address command, and Cisco Express Forwarding for IPv4 has been configured globally on the device with the ip cef command.
ip cef ipv6 unicast-routing ipv6 cef ipv6 cef accounting prefix-length interface gigabitethernet0/0/0 ip address 10.4.9.11 255.0.0.0 media-type 10BaseT ipv6 address 2001:DB8:C18:1::/64 eui-64
Related Topic |
Document Title |
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Cisco Express Forwarding for IPv6 |
Implementing IPv6 Addressing and Basic Connectivity Guide, IPv6 Configuration Guide |
Cisco IOS voice configuration |
Cisco IOS Voice Configuration Library |
Cisco IOS commands |
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IPv6 commands, including voice commands |
Cisco IOS IPv6 Command Reference |
Cisco Unified Border Element configuration |
Cisco Unified Border Element Configuration Guide |
SIP Configuration Guide |
|
Troubleshooting and debugging guides |
Cisco IOS Debug Command Reference |
MIB |
MIBs Link |
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No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
Description |
Link |
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The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. |