Forwarding ports for emule - Printable Version

Forwarding ports for emule - Printable Version

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+--- Thread: Forwarding ports for emule (/thread-3110.html)

Forwarding ports for emule - pofkezas - 2004-10-17

Hey there, I have my Linux box working as a gateway for my windows computer. How do I open ports so that my windows box will get a high ID on emule? My current iptables config is

Code:
# Generated by iptables-save v1.2.9 on Sun Oct 17 16:42:51 2004

*filter

:INPUT ACCEPT [5483:1000737]

:FORWARD DROP [0:0]

:OUTPUT ACCEPT [6884:1994487]

-A INPUT -i ppp0 -p tcp -m tcp --sport 23 -m state --state ESTABLISHED -j ACCEPT

-A INPUT -i eth0 -p tcp -m tcp --sport 4661 -m state --state ESTABLISHED -j ACCEPT

-A INPUT -i ppp0 -p tcp -m tcp --sport 4661 -m state --state ESTABLISHED -j ACCEPT

-A INPUT -i ppp0 -p tcp -m tcp --sport 4662 -m state --state ESTABLISHED -j ACCEPT

-A FORWARD -i ppp0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT

-A FORWARD -i eth1 -o ppp0 -j ACCEPT

COMMIT

# Completed on Sun Oct 17 16:42:51 2004

# Generated by iptables-save v1.2.9 on Sun Oct 17 16:42:51 2004

*nat

:PREROUTING ACCEPT [1943:97405]

:POSTROUTING ACCEPT [3:359]

:OUTPUT ACCEPT [1285:83346]

-A PREROUTING -i ppp0 -p tcp -m tcp --dport 4661 -j DNAT --to-destination 10.0.0.254:4661

-A PREROUTING -i ppp0 -p tcp -m tcp --dport 4662 -j DNAT --to-destination 10.0.0.254:4662

-A PREROUTING -i ppp0 -p udp -m udp --dport 4672 -j DNAT --to-destination 10.0.0.254:4672

-A POSTROUTING -o ppp0 -j MASQUERADE

COMMIT

# Completed on Sun Oct 17 16:42:51 2004

and iptable -L gives me

Code:
Chain INPUT (policy ACCEPT)

target     prot opt source               destination

ACCEPT     tcp  --  anywhere             anywhere            tcp spt:telnet state ESTABLISHED

ACCEPT     tcp  --  anywhere             anywhere            tcp spt:4661 state ESTABLISHED

ACCEPT     tcp  --  anywhere             anywhere            tcp spt:4661 state ESTABLISHED

ACCEPT     tcp  --  anywhere             anywhere            tcp spt:4662 state ESTABLISHED

Chain FORWARD (policy DROP)

target     prot opt source               destination

ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED

ACCEPT     all  --  anywhere             anywhere

Chain OUTPUT (policy ACCEPT)

target     prot opt source               destination

What am I doing wrong here?

Forwarding ports for emule - z0ny - 2004-10-18

Quote:-A INPUT -i eth0 -p tcp -m tcp --sport 4661 -m state --state ESTABLISHED -j ACCEPT-A INPUT -i ppp0 -p tcp -m tcp --sport 4661 -m state --state ESTABLISHED -j ACCEPT

-A INPUT -i ppp0 -p tcp -m tcp --sport 4662 -m state --state ESTABLISHED -j ACCEPT

Are you sure you want '--sport' (source port)? I'm not really into that eMule stuff but I am pretty sure you mean destination ports (like you used in the PREROUTING chain): '--dport'.

Quote:-A INPUT -i ppp0 -p tcp -m tcp --sport 23 -m state --state ESTABLISHED -j ACCEPT

What is that good for anyways (besides the '--sport' thing)? You only accept incoming telnet connections when they're already established - with INPUT's and OUTPUT's default policy ACCEPT. o_O

Quote:-A PREROUTING -i ppp0 -p tcp -m tcp --dport 4661 -j DNAT --to-destination 10.0.0.254:4661

'iptables -t nat -A PREROUTING -i ppp0 -p tcp --dport 4661 -j DNAT --to 10.0.0.254' is quite enough.

z0ny

Forwarding ports for emule - pofkezas - 2004-10-18

ok I kinda modified my config, it looks like this now:

Code:
# Generated by iptables-save v1.2.9 on Mon Oct 18 18:49:02 2004

*nat

:PREROUTING ACCEPT [0:0]

:POSTROUTING ACCEPT [0:0]

:OUTPUT ACCEPT [0:0]

-A PREROUTING -i ppp0 -p tcp -m tcp --dport 4661 -j DNAT --to-destination 10.0.0.254

-A POSTROUTING -o ppp0 -j MASQUERADE

COMMIT

# Completed on Mon Oct 18 18:49:02 2004

# Generated by iptables-save v1.2.9 on Mon Oct 18 18:49:02 2004

*filter

:INPUT ACCEPT [0:0]

:FORWARD DROP [0:0]

:OUTPUT ACCEPT [0:0]

-A INPUT -i eth0 -p tcp -m tcp --dport 23 -m state --state ESTABLISHED -j ACCEPT

-A FORWARD -i ppp0 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT

-A FORWARD -i eth1 -o ppp0 -j ACCEPT

COMMIT

# Completed on Mon Oct 18 18:49:02 2004

But still I get a lowID on all servers.. Any ideas?

Forwarding ports for emule - z0ny - 2004-10-19

Code:
// Flush (clear) all relevant tables

iptables -F INPUT

iptables -F OUTPUT

iptables -F FORWARD

iptables -t nat -F PREROUTING

iptables -t nat -F POSTROUTING

// Setup the default policies

iptables -P INPUT ACCEPT // you may want DROP here...

iptables -P OUTPUT ACCEPT

iptables -P FORWARD DROP // ...or even ACCEPT over here :)

iptables -t nat -P PREROUTING ACCEPT

iptables -t nat -P POSTROUTING ACCEPT

// Enable port routing

iptables -t nat -I PREROUTING -i ppp0 -p tcp --dport 4661 -j DNAT --to 10.0.0.254

// Enable port forwarding and in-to-out communication

iptables -I FORWARD -i ppp0 -p tcp --dport 4661 -j ACCEPT

iptables -I FORWARD -i eth1 -j ACCEPT

// Enable masquerading (NAT)

iptables -t nat -I POSTROUTING -i eth1 -j MASQUERADE

Try it exactly like this before complaining again! [img]<___base_url___>/uploads/emoticons/default_ph34r.png[/img] The paket enters your computer on 4661/tcp through ppp0 and enters the PREROUTING chain. This chain sends the paket (due to the above ruleset) to the FORWARD chain which allows the forwarding of 4661/tcp. Afterwards it will be sent to the POSTROUTING chain (where it won't be touch in this case). This should work... B)

z0ny

Forwarding ports for emule - pofkezas - 2004-10-20

Last line doesnt work

Code:
[root@amdbox root]# iptables -t nat -I POSTROUTING -i eth1 -j MASQUERADE

iptables v1.2.9: Can't use -i with POSTROUTING

Try `iptables -h' or 'iptables --help' for more information.

Forwarding ports for emule - pofkezas - 2004-10-20

ok I got it.. kinda combined the code you z0ny gave me with my masquerade script so now my code looks like this:

Code:
IPTABLES=/sbin/iptables

EXTIF="ppp0"

INTIF="eth1"

$IPTABLES -P INPUT ACCEPT

$IPTABLES -F INPUT

$IPTABLES -P OUTPUT ACCEPT

$IPTABLES -F OUTPUT

$IPTABLES -P FORWARD DROP

$IPTABLES -t nat -P PREROUTING ACCEPT

$IPTABLES -t nat -P POSTROUTING ACCEPT

$IPTABLES -t nat -I PREROUTING -i ppp0 -p tcp --dport 4661 -j DNAT --to 10.0.0.254

$IPTABLES -I FORWARD -i ppp0 -p tcp --dport 4661 -j ACCEPT

$IPTABLES -I FORWARD -i eth1 -j ACCEPT

$IPTABLES -A FORWARD -i $EXTIF -o $INTIF -m state --state ESTABLISHED,RELATED -j ACCEPT

$IPTABLES -A FORWARD -i $INTIF -o $EXTIF -j ACCEPT

$IPTABLES -t nat -A POSTROUTING -o $EXTIF -j MASQUERADE

Thanks alot for your help!