50% of packets lost only on local interfaces

Tue Feb 1 10:14:49 PST 2005

Chris wrote:
> 
> Have tested on 3 boxes.

yes, it's the intended operation and If I don't see it I don't 
believe it but it happens. I ever thought it would be possible.

The weirdest is that it worked in 5.3-RELEASE and some time later, 
whilst I was tracking -stable, aplications began to fail local
network conections. Simple tests with ping showed me as the kernel 
receive packets (tcpdump seems to see inbound packets) but ignores
exacly 50% of them. This makes any sense to someone?

Following the proposed solution for kern/72022 I removed /usr/obj,
all possible harmful options in make.conf and compiled world and 
a GENERIC kernel again without any luck.

> grep '^[^#]' /etc/make.conf
CFLAGS= -pipe
COPTFLAGS= -pipe
NOPROFILE=	true	# Avoid compiling profiled libraries
X_WINDOW_SYSTEM=xorg
PERL_VER=5.8.5
PERL_VERSION=5.8.5
PERL_ARCH=mach
NOPERL=yo
NO_PERL=yo
NO_PERL_WRAPPER=yo
SENDMAIL_CFLAGS=-I/usr/local/include -DSTARTTLS -DSASL=2 -DMILTER  -DLDAPMAP
SENDMAIL_LDFLAGS= -L/usr/local/lib
SENDMAIL_LDADD=-lsasl2 -lssl -lcrypto -lldap -llber

I'm lost here, any help will be welcome.

Regards,

> 5.3-STABLE compiled Jan 5th
> 
> --- 127.0.0.1 ping statistics ---
> 61 packets transmitted, 61 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 0.062/0.073/0.146/0.013 ms
> 
> 5.3-STABLE amd64 build compiled Jan 29th
> 
> --- 127.0.0.1 ping statistics ---
> 60 packets transmitted, 60 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 0.024/0.030/0.048/0.005 ms
> 
> 5.3-Release-P5
> 
> --- 127.0.0.1 ping statistics ---
> 60 packets transmitted, 60 packets received, 0% packet loss
> round-trip min/avg/max/stddev = 0.057/0.089/0.167/0.017 ms
> 
> On Mon, 31 Jan 2005 19:12:52 +0100, José M. Fandiño <freebsd4 at fadesa.es> wrote:
> > 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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