Using ping, tracert, and system debugging ··············································································································· 1

Ping ····················································································································································································· 1

Using a ping command to test network connectivity ···························································································· 1

Ping example ···························································································································································· 1

Tracert ················································································································································································ 3

Prerequisites ······························································································································································ 4

Using a tracert command to identify failed or all nodes in a path ····································································· 4

Tracert example ························································································································································ 4

System debugging ···························································································································································· 5

Debugging information control switches················································································································ 6

Debugging a feature module ·································································································································· 6

Configuring NTP ·························································································································································· 8

Overview ············································································································································································ 8

How NTP works ························································································································································ 8

NTP architecture ······················································································································································· 9

Association modes ················································································································································ 10

NTP security ··························································································································································· 12

Protocols and standards ······································································································································· 13

Configuration restrictions and guidelines ···················································································································· 13

Configuration task list ···················································································································································· 13

Enabling the NTP service ·············································································································································· 13

Configuring NTP association modes ···························································································································· 13

Configuring NTP in client/server mode ·············································································································· 14

Configuring NTP in symmetric active/passive mode ························································································ 14

Configuring NTP in broadcast mode ·················································································································· 15

Configuring NTP in multicast mode ····················································································································· 16

Configuring access control rights ································································································································· 17

Configuring NTP authentication ··································································································································· 17

Configuring NTP authentication in client/server mode ····················································································· 17

Configuring NTP authentication in symmetric active/passive mode ······························································· 19

Configuring NTP authentication in broadcast mode ························································································· 21

Configuring NTP authentication in multicast mode ··························································································· 23

Configuring NTP optional parameters ························································································································· 25

Specifying the source interface for NTP messages ···························································································· 25

Disabling an interface from receiving NTP messages ······················································································· 26

Configuring the maximum number of dynamic associations ············································································ 26

Configuring the local clock as a reference source ····································································································· 27

Displaying and maintaining NTP ································································································································· 27

NTP client/server mode configuration example ········································································································· 28

IPv6 NTP client/server mode configuration example ································································································· 29

NTP symmetric active/passive mode configuration example ··················································································· 30

IPv6 NTP symmetric active/passive mode configuration example ··········································································· 32

NTP broadcast mode configuration example ············································································································· 34

NTP multicast mode configuration example ················································································································ 36

IPv6 NTP multicast mode configuration example ······································································································· 39

Configuration example for NTP client/server mode with authentication ································································· 42

Configuration example for NTP broadcast mode with authentication ····································································· 44