
Chapter 1
| Initial Switch Configuration
Setting the System Clock
– 69 –
Configuring NTP
Requesting the time from a an NTP server is the most secure method. You can
enable NTP authentication to ensure that reliable updates are received from only
authorized NTP servers. The authentication keys and their associated key number
must be centrally managed and manually distributed to NTP servers and clients.
The key numbers and key values must match on both the server and client.
When more than one time server is configured, the client will poll all of the time
servers, and compare the responses to determine the most reliable and accurate
time update for the switch.
To configure NTP time synchronization, enter commands similar to the following.
Console(config)#ntp client
Console(config)#ntp authentication-key 45 md5 thisiskey45
Console(config)#ntp authenticate
Console(config)#ntp server 192.168.3.20
Console(config)#ntp server 192.168.3.21
Console(config)#ntp server 192.168.5.23 key 19
Console(config)#exit
Console#show ntp
Current Time : Apr 29 13:57:32 2011
Polling : 1024 seconds
Current Mode : unicast
NTP Status : Enabled
NTP Authenticate Status : Enabled
Last Update NTP Server : 192.168.0.88 Port: 123
Last Update Time : Mar 12 02:41:01 2013 UTC
NTP Server 192.168.0.88 version 3
NTP Server 192.168.3.21 version 3
NTP Server 192.168.4.22 version 3 key 19
NTP Authentication Key 19 md5 42V68751663T6K11P2J307210R885
Current Time : Apr 2 16:28:34 2013
Polling : 1024 seconds
Current Mode : unicast
NTP Status : Enabled
NTP Authenticate Status : Enabled
Last Update NTP Server : 192.168.5.23 Port: 0
Last Update Time : Apr 2 16:00:00 2013 UTC
NTP Server 192.168.3.20 version 3
NTP Server 192.168.3.21 version 3
NTP Server 192.168.5.23 version 3 key 19
NTP Authentication Key 45 md5 2662T75S5658RU5424180034777
Console#
Summary of Contents for ECS4120-28F
Page 36: ...Contents 36...
Page 38: ...Figures 38...
Page 46: ...Section I Getting Started 46...
Page 70: ...Chapter 1 Initial Switch Configuration Setting the System Clock 70...
Page 86: ...Chapter 2 Using the Command Line Interface CLI Command Groups 86...
Page 202: ...Chapter 5 SNMP Commands Additional Trap Commands 202...
Page 210: ...Chapter 6 Remote Monitoring Commands 210...
Page 216: ...Chapter 7 Flow Sampling Commands 216...
Page 278: ...Chapter 8 Authentication Commands PPPoE Intermediate Agent 278...
Page 360: ...Chapter 9 General Security Measures Port based Traffic Segmentation 360...
Page 384: ...Chapter 10 Access Control Lists ACL Information 384...
Page 424: ...Chapter 11 Interface Commands Power Savings 424...
Page 446: ...Chapter 13 Power over Ethernet Commands 446...
Page 456: ...Chapter 14 Port Mirroring Commands RSPAN Mirroring Commands 456...
Page 488: ...Chapter 17 UniDirectional Link Detection Commands 488...
Page 494: ...Chapter 18 Address Table Commands 494...
Page 554: ...Chapter 20 ERPS Commands 554...
Page 620: ...Chapter 22 Class of Service Commands Priority Commands Layer 3 and 4 620...
Page 638: ...Chapter 23 Quality of Service Commands 638...
Page 772: ...Chapter 25 LLDP Commands 772...
Page 814: ...Chapter 26 CFM Commands Delay Measure Operations 814...
Page 836: ...Chapter 28 Domain Name Service Commands 836...
Page 848: ...Chapter 29 DHCP Commands DHCP Relay Option 82 848...
Page 902: ...Section III Appendices 902...
Page 916: ...Glossary 916...
Page 926: ...CLI Commands 926...
Page 937: ......
Page 938: ...E092017 CS R02...