Server 192.10.1.254 with authentication
Rack1R1#s | inc ntp
ntp authentication-key 1 md5 02252D682829 7
ntp authenticate
ntp trusted-key 1
ntp server 192.10.1.254 key 1
Rack1R1#sh ntp ass de
192.10.1.254 configured, authenticated, our_master, sane, valid, stratum 4
ref ID 127.127.7.1, time AF7D0BB5.1F58ABC8 (11:29:57.122 UTC Mon Apr 19 1993)
our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 0.03, reach 360, sync dist 3.479
delay 6.52 msec, offset -0.1136 msec, dispersion 16000.00
precision 2**18, version 3
org time AF7D0BBA.91DA71F5 (11:30:02.569 UTC Mon Apr 19 1993)
rcv time AF7D0BBA.92AD5CD9 (11:30:02.572 UTC Mon Apr 19 1993)
xmt time AF7D0BBA.903C38FA (11:30:02.563 UTC Mon Apr 19 1993)
filtdelay = 0.00 0.00 7.51 6.52 6.73 9.09 7.35 7.02
filtoffset = 0.00 0.00 0.44 -0.11 -0.04 1.14 0.03 -0.10
filterror = 16000.0 16000.0 0.08 0.09 0.11 0.12 0.14 0.15
configuring access to ntp servers
if acting as an ntp server only for clients in the access-list 1
ntp access-group serve-only 1