timewait sockets held…tw_bucket

$cat /proc/sys/net/ipv4/tcp_max_tw_buckets
180000
$
tcp_max_tw_buckets

Maximal number of timewait sockets held by system simultaneously.
If this number is exceeded time-wait socket is immediately destroyed
and warning is printed. This limit exists only to prevent simple DoS
attacks, you _must_ not lower the limit artificially, but rather increase
 it (probably, after increasing installed memory), if network conditions
 require more than default value.

source :

Linux kernel Documentation .


cifs-1.13/fs/cifs/file.s

 100032:
.LC2776:
100033:         .string "NET_TCP_MAX_TW_BUCKETS"
100034: .LC4101:

de.samba.org/samba/ftp/cifs-cvs/cifs-1.13-2.6-bad.tar.gz - Unknown - Assembly - More from cifs-1.13-2.6-bad.tar.gz »
"Firewall performance measurement"

--- a selection follows.

Size of available TCP port range:
When connecting to the same server on the same port, there are
64,512 non-privileged ports available on the client side as source
 ports. According to RFC793[5], a port cannot be reused until the
 TCP_TIME_WAIT state expires. The recommended timeout value in
 the RFC is 4 minutes, which would mean 268 new request per
 second at the maximum. In the Linux kernel the timeout value of
the TCP_TIME_WAIT state is around 1 minute, which means a
maximum of 1075 new request per second.

source :
Netfilter Performance Testing
József Kadlecsik
KFKI RMKI
kadlec@sunserv.kfki.hu
György Pásztor
SZTE EK
pasztor@linux.gyakg.u-szeged.hu