Administrator Guide

52 Spanning Tree Protocol (STP)...................................................................................784
Protocol Overview..........................................................................................................................................................784
Congure Spanning Tree................................................................................................................................................ 784
Related Conguration Tasks..................................................................................................................................... 784
Important Points to Remember................................................................................................................................ 784
Conguring Interfaces for Layer 2 Mode........................................................................................................................785
Enabling Spanning Tree Protocol Globally.......................................................................................................................786
Adding an Interface to the Spanning Tree Group............................................................................................................788
Removing an Interface from the Spanning Tree Group................................................................................................... 788
Modifying Global Parameters..........................................................................................................................................788
Modifying Interface STP Parameters..............................................................................................................................789
Enabling PortFast...........................................................................................................................................................790
Prevent Network Disruptions with BPDU Guard...................................................................................................... 790
Global BPDU Filtering.....................................................................................................................................................792
Interface BPDU Filtering...........................................................................................................................................792
Selecting STP Root........................................................................................................................................................ 793
STP Root Guard.............................................................................................................................................................794
Root Guard Scenario................................................................................................................................................794
Conguring Root Guard........................................................................................................................................... 795
SNMP Traps for Root Elections and Topology Changes................................................................................................. 796
Displaying STP Guard Conguration...............................................................................................................................796
53 System Time and Date...............................................................................................797
Network Time Protocol...................................................................................................................................................797
Protocol Overview....................................................................................................................................................798
Congure the Network Time Protocol......................................................................................................................798
Enabling NTP........................................................................................................................................................... 798
Conguring NTP Broadcasts....................................................................................................................................799
Disabling NTP on an Interface.................................................................................................................................. 799
Conguring a Source IP Address for NTP Packets...................................................................................................799
Conguring NTP Authentication.............................................................................................................................. 800
Dell Networking OS Time and Date................................................................................................................................802
Conguration Task List ............................................................................................................................................802
Set Daylight Saving Time......................................................................................................................................... 803
54 Tunneling ................................................................................................................. 806
Conguring a Tunnel...................................................................................................................................................... 806
Conguring Tunnel keepalive.......................................................................................................................................... 807
Conguring the ip and ipv6 unnumbered........................................................................................................................807
Conguring the Tunnel allow-remote..............................................................................................................................808
Conguring the tunnel source anylocal...........................................................................................................................808
55 Uplink Failure Detection (UFD)................................................................................. 809
Feature Description........................................................................................................................................................809
How Uplink Failure Detection Works............................................................................................................................... 810
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