Appendix B Troubleshooting
Troubleshooting the 4200 Series Appliance
B-34
Cisco Intrusion Detection System Appliance and Module Installation and Configuration Guide Version 4.1
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Verifying that the Sensor is Synchronized with the NTP Server
To verify that the sensor is synchronized with the NTP server, follow these steps:
Step 1
Log in to the service account.
Step 2
Check to see if the sensor can communicate with the NTP server by running
/usr/sbin/ntpg -p:
sensor# /usr/sbin/ntpq -p
remote refid st t when poll reach delay offset jitter
10.89.147.99 CHU_AUDIO(1) 6 u 47 64 0 0.410 19.457 0.740
LOCAL(0) LOCAL(0) 5 l 59 64 0 0.000 0.000 0.004
In the servers’s IP address line, if the value in the reach column is 0, the sensor
either cannot communicate with the NTP server or the keys do not match.
Step 3
Make sure the sensor can contact the NTP server by running /usr/sbin/ntptrace:
sensor# /usr/sbin/ntptrace
server_ip_address
Step 4
If this is the output, the sensor can contact the NTP server but the key ID or value
is most likely incorrect:
10.89.147.99: stratum 6, offset 0.025372, synch distance 0.00003
Step 5
If this is the output, there is most likely a network connectivity or access problem:
10.89.147.99: ‘Timeout’
Step 6
If you can contact the NTP server, make sure the sensor can authenticate the NTP
server:
sensor# /usr/sbin/ntpq -c assoc
Step 7
In this output, the auth column has
ok
, indicating that the sensor was able to
authenticate the NTP server. If the auth column has
bad
most likely the key ID or
key value configured on the sensor does not match the value configured on the
server.
ind assID status conf reach auth condition last_event cnt
1 1052 f614 yes yes ok sys.peer reachable 1
2 1053 9014 yes yes none reject reachable 1
Содержание IDS-4230-FE - Intrusion Detection Sys Fast Ethernet Sensor
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