Nagios Support Forum

Hi,

We are using Nagios XI.

When we ping a host from Nagios XI GUI duplicate ping is appearing. Sample output is shown below.

PING 10.62.88.45 (10.62.88.45) 56(84) bytes of data.
64 bytes from 10.35.88.23: icmp_seq=1 ttl=246 time=143 ms
64 bytes from 10.35.88.23: icmp_seq=1 ttl=246 time=144 ms (DUP!)
64 bytes from 10.35.88.23: icmp_seq=2 ttl=246 time=142 ms
64 bytes from 10.35.88.23: icmp_seq=2 ttl=246 time=143 ms (DUP!)
64 bytes from 10.35.88.23: icmp_seq=3 ttl=246 time=136 ms
64 bytes from 10.35.88.23: icmp_seq=3 ttl=246 time=143 ms (DUP!)
64 bytes from 10.35.88.23: icmp_seq=4 ttl=246 time=136 ms
64 bytes from 10.35.88.23: icmp_seq=4 ttl=246 time=136 ms (DUP!)
64 bytes from 10.35.88.23: icmp_seq=5 ttl=246 time=136 ms

The device is an Access point and no ping service is configured for this device.

What could be the reason for duplicate ping(DUP!)

Pratap

Hello Pratap,

Typically we see this when a device with the same IP address (with a different MAC address) is hitting it. Other reasons include incorrect load balancing, proxy, or redundancy setup. Also, note that this is expected behavior if you are pinging a multicast group.

Several options to take a look at to see what is going on.

• Use TCPDUMP command and import to Wireshark to see if anything of concern is going on.
• Increase the ping -t value to 60 to see if (dup) goes away, could be false feedback or noise.

Thanks,
Perry

Thank you for the response. You may close this.

Regards,
Pratap