Openwrt
Openwrt knowledge
NVRAM
NVRAM is the EEPROM of the wrt54g. The Settings stored in the NVRAM is used by openwrt to configure the network interfaces and other settings like timezone and so on.
OLSR
OLSR means Optimized Link State Routing protocol.
OLSR is a routing protocol for mobile ad-hoc networks. The protocol is pro-active, table driven and utilizes a technique called multipoint relaying for message flooding. You can configure multiple openwrt routers to talk to each other to find the best route from point A to point B.
WDS
WDS (Wireless Distribution System) can be used to mae a special tunnel between two openwrt's. It is also supported by many other Accesspoints. I didn't bring it to work so i had been looking for another solution. MESH networks soltuions can do that. OLSR is one implementation for that. AODV is another one.
Installing the software
Installing the openwrt firmware
I use this script to takeover the wrt54g. Get your firmware and copy it to the same directory as the takeover script.
Whether to use jffs2 or sqashfs is a philosophical question.
Plug in your wrt54g to you linux box. Configure your box in side 192.168.1.0/24 (not 192.168.1.1!)
| Code: Installing openwrt on the Linksys wrt54g |
wget http://downloads.openwrt.org/whiterussian/rc2/bin/openwrt-wrt54g-jffs2.bin wget https://aachen.uni-dsl.de/download/wrt/Snapshots/rev121/buildroot-rev121/takeover chmod +x takeover cp openwrt-wrt54g-jffs2.bin openwrt-g-code.bin ./takeover |
Wait about 5 minutes. If openwrt is booting the DMZ LED should lightning.
| Code: Configure the network |
nvram set lan_ifname=vlan0 nvram set lan_proto=static nvram set lan_ipaddr=192.168.1.1 nvram set lan_netmask=255.255.255.0 nvram set wifi_ifname=eth1 nvram set wifi_proto=static nvram set wifi_ipaddr=10.1.1.1 nvram set wifi_netmask=255.0.0.0 nvram set wan_ifname=vlan1 nvram set wan_proto=dhcp nvram set wl0_mode=sta nvram set wl0_infra=0 nvram set wl0_ssid=any-ssid nvram set wl0_channel=1 nvram commit |
Installing openvpn
| Code: Installing openvpn |
ipkg update ipkg install openvpn |
| Code: /etc/init.d/S60openvpn |
#!/bin/sh
# load Bridging-Module
#modprobe bridge
openvpn --mktun --dev tap0
# configure bridge
brctl addbr br1
brctl stp br1 off
brctl setfd br1 0
brctl addif br1 vlan0
brctl addif br1 tap0
ifconfig vlan0 0.0.0.0 promisc up
ifconfig tap0 0.0.0.0 promisc up
ifconfig br1 192.168.25.172 netmask 0xffffff00 broadcast 192.168.25.255
echo 1 > /proc/sys/net/ipv4/conf/br1/forwarding
openvpn --config /etc/openvpn/server.conf &
|
| Code: /etc/openvpn/server.conf |
port 1194 proto tcp-server dev tap0 ca /etc/openvpn/keys/ca.crt cert /etc/openvpn/keys/server.crt key /etc/openvpn/keys/server.key # This file should be kept secret dh /etc/openvpn/keys/dh1024.pem #this will assign connecting clients address between the range of 10 and 50 #openwrt IP is 192.168.25.172 server-bridge 192.168.25.172 255.255.255.0 192.168.25.10 192.168.25.50 #this will allow for people to get the same IP address after a reconnect ifconfig-pool-persist /etc/openvpn/ipp.txt push "dhcp-option DNS 192.168.25.179" keepalive 10 120 max-clients 10 persist-key persist-tun |
| Code: /etc/openvpn/server.conf |
#the ip address of the openwrt box remote 10.7.0.1 float proto tcp-client dev tap persist-tun redirect-gateway #to set /etc/resolv.conf if necessary up /etc/openvpn/wlan/client.up down /etc/openvpn/wlan/client.down pull tls-client cert /etc/openvpn/wlan/keys/client1.crt ca /etc/openvpn/wlan/keys/ca.crt key /etc/openvpn/wlan/keys/client1.key |
You now need to make the keys. You can use the easy-rsa script from the openvpn package. Get it from the homepage.
Installing olsrd
| Code: Installing olsrd |
ipkg install olsrd |
| Code: /etc/olsrd.conf |
[...]
Hna4
{
#The Network which the dhcp server is responsable for
10.7.0.0 255.255.255.0
# Setting only on the box which has direct Internet Access
0.0.0.0 0.0.0.0
}
[...]
Interface "eth1"
{
# Hello interval in seconds(float)
HelloInterval 10.0
# HELLO validity time
HelloValidityTime 200.0
# TC interval in seconds(float)
TcInterval 25.0
# TC validity time
TcValidityTime 500.0
# MID interval in seconds(float)
MidInterval 25.0
# MID validity time
MidValidityTime 500.0
# HNA interval in seconds(float)
HnaInterval 25.0
# HNA validity time
HnaValidityTime 500.0
}
|
Append a '&' to 'olsrd $OPTIONS' in /etc/init.d/olsrd so it look like:
olsrd $OPTIONS &
| Code: Starting olsrd |
mv /etc/init.d/olsrd /etc/init.d/S60olsrd /etc/init.d/S60olsrd start |
Configuring dhcp
dhcp-authoritative dhcp-range=eth1,10.7.0.20,10.7.0.200,255.0.0.0,12h dhcp-leasefile=/tmp/dhcp.leases dhcp-option=3,10.7.0.1 dhcp-option=6,10.7.0.1