hi,

ineed to drop the gtalk port for an specific i.p. in my network, i googled for it.. i got it this
Block Access To Outgoing IP TCP / UDP Port Number

It is also possible to block specific port numbers. For example, you can block tcp port # 5050 as follows:
iptables -A OUTPUT -p tcp –dport 5050 -j DROP

To block tcp port # 5050 for an IP address 192.168.1.2 only, enter:
iptables -A OUTPUT -p tcp -d 192.168.1.2 –dport 5050 -j DROP

but when i entre in to my confir
/etc/sysconfig/iptables/
its showng the error

[root@localhost ~]# vim /etc/sysconfig/iptables
[root@localhost ~]# service iptables restart
Flushing firewall rules: [ OK ]
Setting chains to policy ACCEPT: filter nat [ OK ]
Unloading iptables modules: [ OK ]
Applying iptables firewall rules: iptables-restore v1.3.5: multiple -d flags not allowed
Error occurred at line: 14
Try `iptables-restore -h' or 'iptables-restore --help' for more information.
pls help me to sort out this...

Notice the double minus "--" signs on "--dport" option. The simple usual rule with most commands is that single letter options are preceded by single minus "-a -b -c" or equivalent "-abc" and multi-letters options are preceded by double minus "--something --otherthing". Your "-dport" options was interpreted as "-d -p -o -r -t" options by iptables command.

Is wrong , It should be

iptables -A OUTPUT -d 192.168.1.2 -p tcp -–dport 5050 -j DROP

Thanks