Icmpping problem with DNS name

[p5494846]

Hi,guys!
I have a strange problem when using my zabbix. The fping works good through simpe check while the host use IP address, but when using dns name(domain name), it alerts the icmpping item not supported and later became supported itself. I find out the error message in zabbix_server.log like:
item "1234:icmppingsec" became not supported: Cannot send ICMP ping packets to this host.
item "1234:icmpping" became supported

It appears over and over, and it has no regular time. The strange thing is that I have two zabbix servers, this server has the problem while the other one performance erverything OK. That very bothered me, does anyone has the same problem?
By the way, the two servers have the same dns server. When zabbix alerts the item not supported, I use fping and the domain name is ok.
Hope someone help me !!!

[nobodysu]

Something is wrong with your resolver specified on zabbix server: I'm thinking one bogus server and one good.
Of course you can always add hosts entry on needed server, but I strongly suggest that you investigate.

[p5494846]

Something is wrong with your resolver specified on zabbix server: I'm thinking one bogus server and one good.
Of course you can always add hosts entry on needed server, but I strongly suggest that you investigate.

Thanks for reply! I have tried any solution on google, but it didn't work!

[nobodysu]

cat /etc/resolv.conf
cat /etc/sysconfig/network
grep -rI DNS[1-9] /etc

?

[p5494846]

cat /etc/resolv.conf
cat /etc/sysconfig/network
grep -rI DNS[1-9] /etc

?

Thanks，is there anything wrong ?

[root@localhost ~]# cat /etc/resolv.conf

nameserver 114.114.114.114

[root@localhost ~]# cat /etc/sysconfig/network
NETWORKING=yes
HOSTNAME=localhost.localdomain

[root@localhost ~]# grep -rI DNS[1-9] /etc
/etc/sysconfig/network-scripts/ifup-post:  [ -n "$MS_DNS1" ] && DNS1=$MS_DNS1
/etc/sysconfig/network-scripts/ifup-post:  [ -n "$MS_DNS2" ] && DNS2=$MS_DNS2
/etc/sysconfig/network-scripts/ifup-post:  if [ -n "$DNS1" ] && ! grep -q "^nameserver $DNS1" /etc/resolv.conf &&
/etc/sysconfig/network-scripts/ifup-post:    current_replacement="$DNS1"
/etc/sysconfig/network-scripts/ifup-post:    next_replacement="$DNS2"
/etc/sysconfig/network-scripts/ifup-isdn:    if [ -z "$DNS1" -a -z "$DNS2" ]; then
/etc/sysconfig/network-scripts/ifup-isdn:        [ -n "$DNS1" ] && options="$options ms-dns $DNS1"
/etc/sysconfig/network-scripts/ifup-isdn:        [ -n "$DNS2" ] && options="$options ms-dns $DNS2"
/etc/sysconfig/network-scripts/ifup-ippp:    if [ -z "$DNS1" -a -z "$DNS2" ]; then
/etc/sysconfig/network-scripts/ifup-ippp:        [ -n "$DNS1" ] && options="$options ms-dns $DNS1"
/etc/sysconfig/network-scripts/ifup-ippp:        [ -n "$DNS2" ] && options="$options ms-dns $DNS2"
/etc/sysconfig/network-scripts/ifcfg-eth0:DNS1=114.114.114.114
/etc/services:dns2go          1227/tcp                # DNS2Go
/etc/services:dns2go          1227/udp                # DNS2Go

[p5494846]

No one has a idea ?

[nobodysu]

Same configuration on second server and 114.114.114.114 is a working dns, right?
Try to check zabbix database consistency. Replace network cable, network card as a last resort. Thats all I can think of.

[ovas]

Hello!

What happens, if you hit in Google's DNS servers in your network config? Will the problem persist?

Also, if the icmpping check downtime is low, you can adjust timeout accordingly, for example, to 2-5 seconds. Check possible icmpping parameters at: https://www.zabbix.com/documentation...imple_checks?s[]=icmpping

[p5494846]

Same configuration on second server and 114.114.114.114 is a working dns, right?
Try to check zabbix database consistency. Replace network cable, network card as a last resort. Thats all I can think of.

Yes, zabbix version and dns server are the same. Everything works fine when I use ip address, but dns name cann't work, and two servers are virtual machines, so I think it may not be network problem.

[kloczek]

Yes, zabbix version and dns server are the same. Everything works fine when I use ip address, but dns name cann't work, and two servers are virtual machines, so I think it may not be network problem.

Thi issue has nothing to do with zabbix.
Fix you resolver (/etc/resolv.conf) or NSS settings (/etc/nsswitch.conf).

[p5494846]

Hello!

What happens, if you hit in Google's DNS servers in your network config? Will the problem persist?

Also, if the icmpping check downtime is low, you can adjust timeout accordingly, for example, to 2-5 seconds. Check possible icmpping parameters at: https://www.zabbix.com/documentation...imple_checks?s[]=icmpping

Thanks for your help, I have worked it out. Actually, the root cause is the dns server 114.114.114.114. It performs good when i ping it, but sometimes failed to resolve dns name. Because of the bad network quality to Google's DNS server, we usually use it as the secondary dns server.
It's all my fault, i find out that one server has set two dns server while the other one only has 114.114.114.114. But our computers and servers also use 114.114.114.114 which never had problems, so maybe the browser has dns cache, but fping doesn't.

[p5494846]

Thi issue has nothing to do with zabbix.
Fix you resolver (/etc/resolv.conf) or NSS settings (/etc/nsswitch.conf).

Thanks, it's exactly because of the dns server. Maybe fping doesn't cached the domain name resolutions.