write failed: No buffer space available

[Yu He <yuhe --at-- ISI.EDU>]

Hi,

There was a "write failed" error when I test the udp 
throughput among two freebsd machines. These two 
freebsd machines are running 4.10 OS, and one is 
the udp server and the other is the udp client.

The following is the client output:

# iperf -c <server> -u -b 430m
   ------------------------------------------------------------
   Client connecting to <server>, UDP port 5001
   Sending 1470 byte datagrams
   UDP buffer size: 9.00 KByte (default)
   ------------------------------------------------------------
   [  5] local <client> port 3351 connected with <server> port
5001
   write failed: No buffer space available
   [ ID] Interval       Transfer     Bandwidth
   [  5]  0.0- 0.3 sec  15.9 MBytes   435 Mbits/sec
   [  5] Server Report:
   [  5]  0.0- 0.3 sec  15.8 MBytes   425 Mbits/sec  0.056 ms   22/11316
(0.19%)
   [  5] Sent 11316 datagrams
#

I also tried increasing the window size by -w command option, but 
the same error insisted. 

Does anybody know this problem and the cause? I really 
appreciate your help.


Regards,

--Yu