Large RTT or Why doesn't my ping traffic get discarded?

William Herrin bill at
Wed Dec 21 19:56:14 UTC 2022

On Wed, Dec 21, 2022 at 9:10 AM Jason Iannone <jason.iannone at> wrote:
> Here's a question I haven't bothered to ask until now. Can someone please help me understand why I receive a ping reply after almost 5 seconds?
> 64 bytes from icmp_seq=398 ttl=54 time=4915.096 ms
> 64 bytes from icmp_seq=399 ttl=54 time=4310.575 ms
> 64 bytes from icmp_seq=400 ttl=54 time=4196.075 ms
> 64 bytes from icmp_seq=401 ttl=54 time=4287.048 ms
> 64 bytes from icmp_seq=403 ttl=54 time=2280.466 ms
> 64 bytes from icmp_seq=404 ttl=54 time=1279.348 ms
> 64 bytes from icmp_seq=405 ttl=54 time=276.669 ms

Hi Jason,

This usually means a problem on the Linux machine originating the
packet. It has lost the ARP for the next hop or something similar so
the outbound ICMP packet is queued. The glitch repairs itself,
briefly, releasing the queued packets. Then it comes right back.

Bill Herrin

For hire.

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