Cisco Cisco Email Security Appliance X1050 Troubleshooting Guide
Why do I get an DNS resolver alert on boot up?
Document ID: 118252
Contributed by Stephan Fiebrandt and Chris Haag, Cisco TAC
Engineers.
Aug 12, 2014
Engineers.
Aug 12, 2014
Contents
Background Information
Background Information
When booting or rebooting an Cisco Content Security Appliance appliance the below DNS−related alerts may
be sent:
be sent:
−−−
The Critical message is:
Failed to bootstrap the DNS resolver. Unable to contact root servers.
Please check DNS configuration and/or firewall settings.
−−−
Receiving this alert during or soon after system boot−up is not cause for concern.
The AsyncOS alerting mechanism can sometimes activate before the basic OS DNS sub systems are
completely on line, causing the system to send this warning. A future version of AsyncOS will suppress this
alert until the system is fully booted. However, if you receive this alert from a machine that has been running
for a while, or the alert continues to be sent after the boot cycle is complete, the alert may indicate an issue
completely on line, causing the system to send this warning. A future version of AsyncOS will suppress this
alert until the system is fully booted. However, if you receive this alert from a machine that has been running
for a while, or the alert continues to be sent after the boot cycle is complete, the alert may indicate an issue
The AsyncOS alerting mechanism can sometimes activate before the basic OS DNS sub systems are
completely on line, causing the system to send r firewall settings.'
completely on line, causing the system to send r firewall settings.'
Updated: Aug 12, 2014
Document ID: 118252