50% of packets lost only on local interfaces

[JoséM.Fandiño]

Hello,

 It sounds weird but tcp/ip traffic directed to _local_ interfaces,
and only _local_ interfaces, always cause 50% of packets lost. Of 
course there isn't packet filters activated.

I'm running -stable (the last update was this past weekend)

There is another report like this:
http://www.FreeBSD.org/cgi/query-pr.cgi?pr=kern/72022
but the suggested solution doesn't works in my case.

ping to local interfaces get replies for 50% of the packets:

> ping -c 512 127.0.0.1
[snip]
--- 127.0.0.1 ping statistics ---
512 packets transmitted, 257 packets received, 49% packet loss
round-trip min/avg/max/stddev = 0.046/0.049/0.077/0.004 ms

> ping -c 512 10.20.30.2
[snip]
--- 10.20.30.2 ping statistics ---
512 packets transmitted, 254 packets received, 50% packet loss
round-trip min/avg/max/stddev = 0.017/0.049/0.071/0.004 ms

Also running tcpdump on localhost shows as the kernel stop from 
responding to packets without an apparent motive.

> tcpdump -n -i lo0
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on lo0, link-type NULL (BSD loopback), capture size 96 bytes
[snip]
17:58:15.516451 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 76
17:58:15.516476 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo reply seq 76
17:58:16.517321 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 77
17:58:16.517347 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo reply seq 77
17:58:17.518158 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 78
17:58:18.519042 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 79
17:58:19.519853 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 80
17:58:20.520698 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 81
17:58:21.521548 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 82
17:58:22.522392 IP 127.0.0.1 > 127.0.0.1: icmp 64: echo request seq 83

more tests, to the lan router:

> ping -c 500 10.20.30.6
[snip]
--- 10.20.30.6 ping statistics ---
500 packets transmitted, 500 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.565/2.015/40.189/2.385 ms

from the lan router:

Router#ping
Protocol [ip]: 
Target IP address: 10.20.30.2
Repeat count [5]: 500
Datagram size [100]: 
Timeout in seconds [2]: 
Extended commands [n]: 
Sweep range of sizes [n]: 
Type escape sequence to abort.
Sending 500, 100-byte ICMP Echos to 10.20.30.2, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!
Success rate is 99 percent (498/500), round-trip min/avg/max = 1/2/12 ms


 I don't find any explanation for this, but I'd like to know if there is 
any solution?

Thank you.

I put the whole test (dmesg, make.conf, etc)in this URL so you can see 
all numbers.
http://195.55.55.164/tests/FreeBSD/report.txt

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