tcpdrop
FreeBSD 5.4 was released last week and it featured a new command tcpdrop. tcpdrop is obtained from OpenBSD and is used to close selected TCP connection. Description of the command:
The tcpdrop command drops the TCP connection specified by the local address laddr, port lport and the foreign address faddr, port fport. Addresses and ports can be specified by name or numeric value.
Example of when to use this command, if a connection to httpd is causing congestion on a network link, one can drop the TCP session in charge:
fstat | egrep ‘httpd.internet.<—’
www httpd 21307 3* internet stream tcp \
0xd1007ca8 192.168.5.41:80 <-- 192.168.5.1:26747
Use the following command to drop the connection:
# tcpdrop 192.168.5.41 80 192.168.5.1 26747