https://community.cisco.com/t5/network-access-control/ntp-configuration-with-authentication/m-p/3724166#M3376 <P>Thankyou, so i guess the config is good but could in addition use ACLs to filter the NTP sources</P> Fri, 12 Oct 2018 07:32:53 GMT Mokhalil82 2018-10-12T07:32:53Z https://community.cisco.com/t5/network-access-control/ntp-configuration-with-authentication/m-p/3719829#M3370 <P>Hi</P> <P>I am using 2 routers in the DC as NTP servers which will be getting their time from the domain controllers. Then all our network devices will be using the 2 routers as a primary and secondary NTP server. I am also looking to configure NTP authentication.</P> <P>&nbsp;</P> <P>I have the following configuration, is there anything I could add or remove?</P> <P>&nbsp;</P> <P>NTP SERVERS</P> <P>ntp server x.x.x.x (Internal DC - No Authentication)<BR />ntp authentication-key 1 md5 xxx<BR />ntp max-associations 100<BR />ntp trusted-key 1<BR />ntp trusted-key 2<BR />ntp peer y.y.y.y</P> <P>&nbsp;</P> <P>ntp server y.y.y.y (Internal DC - No Authentication)<BR />ntp authentication-key 2 md5 xxx<BR />ntp max-associations 100<BR />ntp trusted-key 1<BR />ntp trusted-key 2<BR />ntp peer x.x.x.x</P> <P>&nbsp;</P> <P>CLIENT</P> <P>ntp authentication-key 1 md5 xxx<BR />ntp authentication-key 2 md5 xxx<BR />ntp authenticate<BR />ntp server x.x.x.x key 1 prefer<BR />ntp server y.y.y.y key 2<BR />ntp trusted-key 1<BR />ntp trusted-key 2</P> Fri, 21 Feb 2020 19:01:55 GMT https://community.cisco.com/t5/network-access-control/ntp-configuration-with-authentication/m-p/3719829#M3370 Mokhalil82 2020-02-21T19:01:55Z https://community.cisco.com/t5/network-access-control/ntp-configuration-with-authentication/m-p/3719899#M3373 <P>Hi,</P> <P>You could also use an ACL to further restrict who can communicate with the NTP server. <A href="https://www.cisco.com/c/en/us/support/docs/availability/high-availability/19643-ntpm.html" target="_self">This</A> link might be of use to you</P> <P>HTH</P> Fri, 05 Oct 2018 12:29:32 GMT https://community.cisco.com/t5/network-access-control/ntp-configuration-with-authentication/m-p/3719899#M3373 Rob Ingram 2018-10-05T12:29:32Z https://community.cisco.com/t5/network-access-control/ntp-configuration-with-authentication/m-p/3724166#M3376 <P>Thankyou, so i guess the config is good but could in addition use ACLs to filter the NTP sources</P> Fri, 12 Oct 2018 07:32:53 GMT https://community.cisco.com/t5/network-access-control/ntp-configuration-with-authentication/m-p/3724166#M3376 Mokhalil82 2018-10-12T07:32:53Z