dup ping received...

I have the strangest problem and I cannot figure this one out, but let me try to explain and see if someone have an idea what could cause this.

Current state:

Ping host A, i.e, 1.1.1.1 from one terminal.

ping 1.1.1.1

PING 1.1.1.1 (1.1.1.1): 56 data bytes

64 bytes from 1.1.1.1: icmp_seq=0 ttl=59 time=3.425 ms

open another terminal and ping host B, i.e. 8.8.8.8 meanwhile we keep pinging 1.1.1.1

ping 8.8.8.8

PING 8.8.8.8 (8.8.8.8): 56 data bytes

64 bytes from 8.8.8.8: icmp_seq=0 ttl=118 time=16.262 ms

64 bytes from 1.1.1.1: icmp_seq=4 ttl=59 time=3.658 ms

64 bytes from 8.8.8.8: icmp_seq=1 ttl=118 time=16.135 ms

^C--- 8.8.8.8 ping statistics ---

2 packets transmitted, 3 packets received, -- somebody is printing forged packets!

If we look at the first terminal, host A.

ping 1.1.1.1

PING 1.1.1.1 (1.1.1.1): 56 data bytes

64 bytes from 1.1.1.1: icmp_seq=0 ttl=59 time=3.429 ms

64 bytes from 1.1.1.1: icmp_seq=1 ttl=59 time=3.468 ms

64 bytes from 1.1.1.1: icmp_seq=2 ttl=59 time=3.571 ms

64 bytes from 1.1.1.1: icmp_seq=3 ttl=59 time=3.573 ms

64 bytes from 8.8.8.8: icmp_seq=0 ttl=118 time=16.253 ms (DUP!)

64 bytes from 1.1.1.1: icmp_seq=4 ttl=59 time=3.701 ms

64 bytes from 8.8.8.8: icmp_seq=1 ttl=118 time=16.165 ms (DUP!)

64 bytes from 1.1.1.1: icmp_seq=5 ttl=59 time=3.566 ms

64 bytes from 1.1.1.1: icmp_seq=6 ttl=59 time=3.348 ms

I do not find duplicate packages in wireshark.

I cannot reproduce this on any VM hosted on my Macbook.

I cannot reproduce this on any other machine on the network.

I reproduce this with both wireless and cable.

Any thoughts what can cause this? or is it just a reinstallation left to do.. ?