50% of packets lost only on local interfaces

Mon Feb 7 02:16:23 PST 2005

"José M. Fandiño" wrote:
> 
> 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.

Finally, I found the culprit:

CFLAGS=""     \  100% of the transmited traffic is received
COPTFLAGS=""  / 

CFLAGS= -pipe     \  50% of the transmited traffic is received
COPTFLAGS= -pipe  /

CFLAGS= -O -pipe     \  100% of the transmited traffic is received
COPTFLAGS= -O -pipe  /

> 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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