Setup is latest Fusion (7.1.0) on latest Yosemite (10.10.1) and a VM running Debian 7.6 in 64 bits and Network is configured to "Share with my Mac".
Here is what happens when I ping 127.0.0.1 in the virtual machine, everything normal:
PING 127.0.0.1 (127.0.0.1) 56(84) bytes of data.
64 bytes from 127.0.0.1: icmp_req=1 ttl=64 time=0.029 ms
64 bytes from 127.0.0.1: icmp_req=2 ttl=64 time=0.023 ms
64 bytes from 127.0.0.1: icmp_req=3 ttl=64 time=0.026 ms
64 bytes from 127.0.0.1: icmp_req=4 ttl=64 time=0.023 ms
64 bytes from 127.0.0.1: icmp_req=5 ttl=64 time=0.023 ms
64 bytes from 127.0.0.1: icmp_req=6 ttl=64 time=0.026 ms
64 bytes from 127.0.0.1: icmp_req=7 ttl=64 time=0.022 ms
64 bytes from 127.0.0.1: icmp_req=8 ttl=64 time=0.024 ms
64 bytes from 127.0.0.1: icmp_req=9 ttl=64 time=0.020 ms
--- 127.0.0.1 ping statistics ---
9 packets transmitted, 9 received, 0% packet loss, time 7999ms
rtt min/avg/max/mdev = 0.020/0.024/0.029/0.002 ms
And here is what happens when I ping the other side of the network between guest and host:
PING 192.168.209.2 (192.168.209.2) 56(84) bytes of data.
64 bytes from 192.168.209.2: icmp_req=1 ttl=128 time=1474 ms
64 bytes from 192.168.209.2: icmp_req=2 ttl=128 time=748 ms
64 bytes from 192.168.209.2: icmp_req=3 ttl=128 time=432 ms
64 bytes from 192.168.209.2: icmp_req=4 ttl=128 time=6.23 ms
64 bytes from 192.168.209.2: icmp_req=5 ttl=128 time=13.0 ms
64 bytes from 192.168.209.2: icmp_req=6 ttl=128 time=505 ms
64 bytes from 192.168.209.2: icmp_req=7 ttl=128 time=1665 ms
64 bytes from 192.168.209.2: icmp_req=8 ttl=128 time=1949 ms
64 bytes from 192.168.209.2: icmp_req=9 ttl=128 time=2135 ms
64 bytes from 192.168.209.2: icmp_req=10 ttl=128 time=2340 ms
64 bytes from 192.168.209.2: icmp_req=11 ttl=128 time=2415 ms
64 bytes from 192.168.209.2: icmp_req=12 ttl=128 time=2010 ms
64 bytes from 192.168.209.2: icmp_req=13 ttl=128 time=2854 ms
64 bytes from 192.168.209.2: icmp_req=14 ttl=128 time=2667 ms
64 bytes from 192.168.209.2: icmp_req=15 ttl=128 time=1738 ms
64 bytes from 192.168.209.2: icmp_req=16 ttl=128 time=1470 ms
64 bytes from 192.168.209.2: icmp_req=17 ttl=128 time=1311 ms
64 bytes from 192.168.209.2: icmp_req=18 ttl=128 time=910 ms
64 bytes from 192.168.209.2: icmp_req=19 ttl=128 time=6.41 ms
64 bytes from 192.168.209.2: icmp_req=20 ttl=128 time=7.16 ms
64 bytes from 192.168.209.2: icmp_req=21 ttl=128 time=212 ms
64 bytes from 192.168.209.2: icmp_req=22 ttl=128 time=433 ms
64 bytes from 192.168.209.2: icmp_req=23 ttl=128 time=485 ms
64 bytes from 192.168.209.2: icmp_req=24 ttl=128 time=992 ms
64 bytes from 192.168.209.2: icmp_req=25 ttl=128 time=1655 ms
--- 192.168.209.2 ping statistics ---
27 packets transmitted, 25 received, 7% packet loss, time 26035ms
rtt min/avg/max/mdev = 6.237/1217.725/2854.815/889.655 ms, pipe 3
Has anybody seen such a crazy behaviour? It's all on the same physical machine!
There is no CPU load or network load or other load on either guest or host...
Thanks!