help... (iptables, ipchains )

From: remoter (bright_zh@163.net)
Date: 06/22/02 

From: bright_zh@163.net (remoter)
Date: 21 Jun 2002 18:37:48 -0700

there is a rule in my old ipchains:

ipchains -A forward -j MASQ -s 192.168.0.0/24 -d xxx.xxx.xxx.xxx/32
1111 -p udp
[intenal client want access xxx.xxx.xxx.xxx:1111(only one public
network server) through SNAT]

how can I change to iptables rule?