Max nbr of connections & Send / Receive Window 1

[yowza]

We have a Solaris 8 ldap server that one site is unable to connect to. I did a netstat -an. The Swin is 8760 and Rwin is 24820 for that site. Other connections have a value of 32768 for the Swin/Rwin. Could this be the problem? I thought that the Send/Recive windows are basically set to the largest amount the sending host can accept. Any ideas on this?

Second question. Is there a maximum number of connections that can be opened at any one time? If so, does anyone know if this can be changed on a Solaris box?
Thanks!!

Yowza

 

[jimbopalmer]

Your Send Window (SWIN) cannot be larger than your configuration or the other box's Receive Window (RWIN). Suns (pre-Solaris) have 8k windows by default so you send window needs to follow that.

The default buffer size for a network session in Solaris prior to Solaris 8 is just 8k, but with 16k token ring, FDDI, fast ethernet, and gigabit ethernet, you may well want more buffer space so your CPU can be distracted yet still have buffers to capure network packets. (I think 64k is the max size)

The commands to enlarge these buffers change this session, so need to be run at every startup.  we put them in /etc/rc3.d as S95ndd

#       Set the TCP hiwater marks to 64K to improve SunSwift SBus
#       Adapter performace.   JJP 22-Aug-2000
case "$1" in
'start')
  echo "Setting local kernel parameters...\c"
  ndd -set /dev/tcp tcp_xmit_hiwat 65535
  ndd -set /dev/tcp tcp_recv_hiwat 65535
  ndd -set /dev/tcp tcp_cwnd_max 65534
  echo ""
;;
'stop')
  echo "No kernel parameters changed."
;;

*)
  echo "Usage:$0 {start|stop}"
;;
esac
exit 0



I tried to remain child-like, all I acheived was childish.

 

[yowza]

Thanks much Jimbopalmer! Couldn't ask for a better explanation!!

yowza