suffering from poor network performance...

Bill Fumerola billf at FreeBSD.org
Tue Dec 16 20:32:34 PST 2003


[ this isn't really -net material ]

On Tue, Dec 16, 2003 at 07:50:57PM -0800, Kevin Stevens wrote:

> >First, Barney was correct: using "ping -f" will run into the ICMP 
> >response limitation.  Try using "ping -i 0.01 _hostname_", instead, 
> >and you may find out that you don't have a problem with packet loss at 
> >all at this lower speed.
> 
> I wish I had a FreeBSD box to check this on, but from an OS X G5 to an 
> Athlon WinXP box (both at 100% CPU from distribfolding client:

which is completely irrelevant because your winxp machine doesn't have
the aforementioned icmp response limiter.

> That's through a cheap Gb switch.  Just a data point.

... albiet a useless one.

[ SECURE !1 ]$ sudo ping -f choker.corp                               
PING choker.corp.yahoo.com (216.145.52.228): 56 data bytes
.............................................................^C
--- choker.corp.yahoo.com ping statistics ---
459 packets transmitted, 398 packets received, 13% packet loss
round-trip min/avg/max/stddev = 0.221/0.227/0.302/0.010 ms

$ dmesg | tail -1                                              (~)
Limiting icmp ping response from 246 to 200 packets/sec
[choker.corp(ttyq0)-fumerola Tue16Dec/20:27:57]
[ SECURE !4 ]$ sudo sysctl net.inet.icmp.icmplim=0                     
net.inet.icmp.icmplim: 200 -> 0

[scurvy.corp(ttyp1)-fumerola Tue16Dec/20:28:19]
[ SECURE !3 ]$ sudo ping -f -c 10000 choker.corp                         
PING choker.corp.yahoo.com (216.145.52.228): 56 data bytes
..
--- choker.corp.yahoo.com ping statistics ---
10000 packets transmitted, 10000 packets received, 0% packet loss

-- 
- bill fumerola / fumerola at yahoo-inc.com / billf at FreeBSD.org




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