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ping (DUP!)

asked 2012-04-09 15:10:57 -0500

ztank1013 gravatar image

I sometimes use the following command to check my connectivity

ping -a

Thant cool IP address is actually the main Google DNS server and it is probably a good target to query with ping because it is most likely UP and available to respond to pings.

For the first time today I had a response to a ping with a (DUP!) sting as a trailer, like this:

64 bytes from icmp_req=304 ttl=50 time=371 ms (DUP!)

Does anybody know what does it mean?

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That's cool,i didn't really know about it, i use to ping :)

Akshay gravatar imageAkshay ( 2012-04-10 13:39:34 -0500 )edit

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answered 2012-04-09 16:08:18 -0500

skytux gravatar image

I don't know, but man ping says:


ping will report duplicate and damaged packets. Duplicate packets should never occur, and seem to be caused by inappropriate link-level retransmis‐ sions. Duplicates may occur in many situations and are rarely (if ever) a good sign, although the presence of low levels of duplicates may not always be cause for alarm.

Damaged packets are obviously serious cause for alarm and often indicate broken hardware somewhere in the ping packet's path (in the network or in the hosts).

Does it help?


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answered 2012-04-10 13:18:00 -0500

Akshay gravatar image

The "DUP" means that "ping" received two replies to one enquiry - the icmp_sequence number is duplicated.

This almost certainly means faulty or misconfigured equipment somewhere - for example, a bad netmask setting.

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answered 2012-07-27 23:39:34 -0500

helper27 gravatar image

updated 2012-07-27 23:45:19 -0500

hi, you can check your ping test here ...just enter the server name and get the ping details...

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Asked: 2012-04-09 15:10:57 -0500

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Last updated: Jul 27 '12