Concept Guide

Conguring a Custom-dened Period for NTP time Synchronization..............................................................966
57 Tunneling................................................................................................................................................. 967
Conguring a Tunnel......................................................................................................................................................967
Conguring Tunnel Keepalive Settings........................................................................................................................968
Conguring a Tunnel Interface.....................................................................................................................................968
Conguring Tunnel Allow-Remote Decapsulation......................................................................................................969
Conguring the Tunnel Source Anylocal.....................................................................................................................969
58 Uplink Failure Detection (UFD)................................................................................................................. 971
Feature Description........................................................................................................................................................ 971
How Uplink Failure Detection Works........................................................................................................................... 972
UFD and NIC Teaming................................................................................................................................................... 973
Important Points to Remember....................................................................................................................................973
Conguring Uplink Failure Detection............................................................................................................................974
Clearing a UFD-Disabled Interface...............................................................................................................................975
Displaying Uplink Failure Detection.............................................................................................................................. 976
Sample Conguration: Uplink Failure Detection......................................................................................................... 978
59 Upgrade Procedures................................................................................................................................980
Get Help with Upgrades............................................................................................................................................... 980
60 Virtual LANs (VLANs).............................................................................................................................. 981
Default VLAN................................................................................................................................................................. 982
Port-Based VLANs........................................................................................................................................................ 982
VLANs and Port Tagging.............................................................................................................................................. 983
Conguration Task List..................................................................................................................................................983
Creating a Port-Based VLAN................................................................................................................................. 983
Assigning Interfaces to a VLAN............................................................................................................................. 984
Moving Untagged Interfaces................................................................................................................................. 985
Assigning an IP Address to a VLAN.......................................................................................................................986
Conguring Native VLANs........................................................................................................................................... 986
Enabling Null VLAN as the Default VLAN...................................................................................................................987
61 Virtual Link Trunking (VLT).......................................................................................................................988
Overview.........................................................................................................................................................................988
VLT Terminology....................................................................................................................................................... 991
Layer-2 Trac in VLT Domains...............................................................................................................................992
Interspersed VLANs................................................................................................................................................ 993
VLT on Core Switches.............................................................................................................................................993
Enhanced VLT..........................................................................................................................................................994
Congure Virtual Link Trunking....................................................................................................................................995
Important Points to Remember............................................................................................................................. 995
Conguration Notes................................................................................................................................................ 996
Primary and Secondary VLT Peers........................................................................................................................999
RSTP and VLT........................................................................................................................................................ 1000
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