[LUG] iptables redirect

[Alex Charrett <alex@xxxxxxxxxxxx>]

I'm getting some weird iptables behaviour - anyone got any ideas?

Some iptables snippits from a server I'm looking at...


So first, I want to accept port 2000 connections from a certian IP:

iptables -A INPUT -i eth1 -s $WORKSTATION -d $THIS_SERVER -p tcp 
--dport 2000 -j ACCEPT


Then I want to redirect 2000 to 3000 as the firewall in front of the 
workstation doesn't allow port 3000 out:

iptables -t nat -A PREROUTING -i eth1 -s $WORKSTATION -p tcp --dport 
2000 -j REDIRECT --to-port 3000


Now by default, I want to drop stuff I've not explicitly allowed.  But 
this is preventing the above working, unless i change DROP to DENY.

iptables -A INPUT -i eth1 -m state --state NEW,INVALID -j DROP


I'm sure there are some people with a better understanding of iptables 
than me on here :)

Cheers,
Alex.

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