CCUM 10.5.x DNS unreachable

[sprintership-il]

Experts,

Since the beginning when we set up CCUM we deal with DNS unreachable message on CCUM. I think all is ok with our DNS's (windows based).

Thank You

[Brandon Buffin]

Can you verify that CUCM has the correct DNS servers? Use the command "show network eth0" from the CLI.

Brandon

[sprintership-il]

Thank you Brandon,

I have SSH-ed to CCUM and from console

admin:show network eth0:

Ethernet 0
DHCP : disabled Status : up
IP Address : 192.168.100.100 IP Mask : 255.255.255.000
Link Detected: yes Mode : Auto disabled, Full, 10000 Mbits/s
Duplicate IP : no

DNS
Primary : 192.168.100.25 Secondary : 192.168.100.38
Options : timeout:5 attempts:2
Domain : localdomain
Gateway : 192.168.100.1 on Ethernet 0

[Brandon Buffin]

Are these the correct DNS servers? Can you ping them from CUCM with this command:

utils network ping 192.168.100.25

[sprintership-il]

yes both are pingable from CCUM

[Jitender Bhandari]

Hi

can you attach output of "utils diagnose test" from CUCM

JB

[sprintership-il]

is that utils diagnose test will affect somehow performance? Asking because this is production environment ....

Thank You

[sprintership-il]

admin:utils diagnose test

Log file: platform/log/diag5.log

Starting diagnostic test(s)
===========================
test - disk_space : Passed (available: 7189 MB, used: 12440 MB)
skip - disk_files : This module must be run directly and off hours
test - service_manager : Passed
test - tomcat : Passed
test - tomcat_deadlocks : Passed
test - tomcat_keystore : Passed
test - tomcat_connectors : Passed
test - tomcat_threads : Passed
test - tomcat_memory : Passed
test - tomcat_sessions : Passed
skip - tomcat_heapdump : This module must be run directly and off hours
test - validate_network : Reverse DNS lookup mismatch
test - raid : Passed
test - system_info : Passed (Collected system information in diagnostic log)
test - ntp_reachability : Passed
test - ntp_clock_drift : Passed
test - ntp_stratum : Passed
skip - sdl_fragmentation : This module must be run directly and off hours
skip - sdi_fragmentation : This module must be run directly and off hours

Diagnostics Completed

The final output will be in Log file: platform/log/diag5.log

Please use 'file view activelog platform/log/diag5.log' command to see the output

[sprintership-il]

est - validate_network : Reverse DNS lookup mismatch

I have checked my DNS for main CCUM and looks like I have two HOST(A) records for same IP ccm1 and callmanager have same IP, ccm2, cuc1 and cuc2 are different. 

Should I delete callmanager ? Or should I create alias to callmanager ?

[Brandon Buffin · Accepted solution]

Seems that new DNS checks in later versions of CUCM complain about duplicate DNS entries. Looks like a bug, but I suppose it is normal behavior. Delete one of the two entries pointing to the publisher.

Brandon

[sprintership-il]

Thank you Brandon, is there any way to refresh dns on ccum? I have created an alias to callmanager pointing to ccm1. But message still there.

I would rather not reboot ccum. Thank You

[Jitender Bhandari · Accepted solution]

Hi

Reason i wanted you to do the "utils diagnose test" is it tests both forward \ revers DNS, you should just fix the DNS entry on DNS server CUCM would take care if itself.

(Rate if it helps)

JB

[sprintership-il]

thank you, what about if I just delete all entries for ccum and cum and recreate them, just curious if that helps - if this is really DNS not bug on ccum side. 

[sprintership-il]

nevermind, the message just disappear, looks like dual entry for ccum caused that,

deleting one of them and creating an alias fix the issue, Thank you all for help.

Have a nice weekend !!!

[wendy.fox]

I have the same Warning: DNS Unreachable on my Unity server.  I ran the show network eth0 and it shows the correct DNS servers and both are pingable from Unity.  I recently upgraded from 10.5.1 to 10.5.2

I ran the utils diagnose test.  See the below results

admin:utils diagnose test

Log file: platform/log/diag1.log

Starting diagnostic test(s)
===========================
test - disk_space : Passed (available: 27154 MB, used: 8857 MB)
skip - disk_files : This module must be run directly and off hours
test - service_manager : Passed
test - tomcat : Passed
test - tomcat_deadlocks : Passed
test - tomcat_keystore : Passed
test - tomcat_connectors : Passed
test - tomcat_threads : Passed
test - tomcat_memory : Passed
test - tomcat_sessions : Passed
skip - tomcat_heapdump : This module must be run directly and off hours
test - validate_network : Forward DNS lookup failed
test - raid : Passed
test - system_info : Passed (Collected system information in diagnostic log)
test - ntp_reachability : Warning
The NTP service is restarting, it can take about 5 minutes.

test - ntp_clock_drift : Warning
The local clock is not synchronised.
None of the designated NTP servers are reachable/functioning or legitimate.

test - ntp_stratum : Warning
The local clock is not synchronised.
None of the designated NTP servers are reachable/functioning or legitimate.

skip - sdl_fragmentation : This module must be run directly and off hours
skip - sdi_fragmentation : This module must be run directly and off hours

Diagnostics Completed

The final output will be in Log file: platform/log/diag1.log

Please use 'file view activelog platform/log/diag1.log' command to see the output