OpenWrt Forum Archive

Topic: Making NAT work?

The content of this topic has been archived on 1 Apr 2018. There are no obvious gaps in this topic, but there may still be some posts missing at the end.

Hi All,
I have a WRT54G, with 7.09 installed and then x-wrt added. I have this arrangement:

PCs >hardwired> WRT54g+kamikaze >wireless> Netgear DG834 Modem/Router

I have the PCs on the wrt54g lan segment, they get IPs by DHCP OK, and the wrt54g gets it's IP by DHCP OK from the Netgear.

I can ssh into the wrt54g ok and ping PCs on the lan side and the netgear router on the WLAN side.

My client PCs however report ' Network is unreachable' when I try to ping an internet IP. The same thing happens when I try to ping an Internet IP from ssh on the router.

What do I need to do to allow all the client PCs to properly access the 'net?

Sorry if this is covered in a FAQ somewhere, I've googled and searched openwrt.org for an hour or three.

Cheers,

jl

Current iptables -L   and route print are:

root@OpenWrt:/etc# iptables -L
Chain INPUT (policy DROP)
target     prot opt source               destination
DROP       all  --  anywhere             anywhere            state INVALID
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED
DROP       tcp  --  anywhere             anywhere            tcp option=!2 flags:SYN/SYN
input_rule  all  --  anywhere             anywhere
input_wan  all  --  anywhere             anywhere
LAN_ACCEPT  all  --  anywhere             anywhere
ACCEPT     icmp --  anywhere             anywhere
ACCEPT     gre  --  anywhere             anywhere
REJECT     tcp  --  anywhere             anywhere            reject-with tcp-reset
REJECT     all  --  anywhere             anywhere            reject-with icmp-port-unreachable

Chain FORWARD (policy DROP)
target     prot opt source               destination
DROP       all  --  anywhere             anywhere            state INVALID
TCPMSS     tcp  --  anywhere             anywhere            tcp flags:SYN,RST/SYN TCPMSS clamp to PMTU
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED
forwarding_rule  all  --  anywhere             anywhere
forwarding_wan  all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere

Chain OUTPUT (policy DROP)
target     prot opt source               destination
DROP       all  --  anywhere             anywhere            state INVALID
ACCEPT     all  --  anywhere             anywhere            state RELATED,ESTABLISHED
output_rule  all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere
REJECT     tcp  --  anywhere             anywhere            reject-with tcp-reset
REJECT     all  --  anywhere             anywhere            reject-with icmp-port-unreachable

Chain LAN_ACCEPT (1 references)
target     prot opt source               destination
RETURN     all  --  anywhere             anywhere
ACCEPT     all  --  anywhere             anywhere

Chain forwarding_rule (1 references)
target     prot opt source               destination

Chain forwarding_wan (1 references)
target     prot opt source               destination

Chain input_rule (1 references)
target     prot opt source               destination

Chain input_wan (1 references)
target     prot opt source               destination

Chain output_rule (1 references)
target     prot opt source               destination
root@OpenWrt:/etc# route print
BusyBox v1.4.2 (2007-09-29 09:01:24 CEST) multi-call binary

Usage: route [{add|del|delete}]

Edit the kernel's routing tables

Options:
        -n      Dont resolve names
        -e      Display other/more information
        -A inet{6}      Select address family

root@OpenWrt:/etc# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     *               255.255.255.0   U     0      0        0 eth0.0
192.168.0.0     *               255.255.255.0   U     0      0        0 wl0

in the default network set-up the wan is thought to be the gateway to internet.
But in your case it is via the bridged lan/wifi net. So move the gateway definition to the lan section and give it the modem/router's wifi IP.

The discussion might have continued from here.