Continuing my research into mesh networking, I was recommended to use TP-Link 3040 and 3600 access points as mesh nodes, and the pair I bought arrived on Friday. Here are my notes on how to set up the MR3040 as a mesh node using OpenWrt.
I started by following the instructions on the OpenWRT wiki for TL-MR3040, and downloaded the recommended firmware image (openwrt-ar71xx-generic-tl-mr3040-v2-squashfs-factory.bin) and uploaded it into the original web interface. The flashing went fine, and the machine was available via telnet on the ethernet port. After logging in and setting the root password, ssh was available and I could start to set it up as a batman-adv mesh node.
I started off by reading the instructions from Wireless Africa, which had quite a lot of useful information, but eventually I followed the recipe from the Open Mesh wiki for using batman-adv on OpenWrt. A small snag was the fact that the opkg install kmod-batman-adv command did not work as it should. The batman-adv kernel module would fail to load because its dependency crc16 was not already loaded. I reported the bug to the openwrt project and hope it will be fixed soon. But the problem only seem to affect initial testing of batman-adv, as configuration seem to work when booting from scratch.
The setup is done using files in /etc/config/. I did not bridge the Ethernet and mesh interfaces this time, to be able to hook up the box on my local network and log into it for configuration updates. The following files were changed and look like this after modifying them:
/etc/config/network
config interface 'loopback'
option ifname 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'
config globals 'globals'
option ula_prefix 'fdbf:4c12:3fed::/48'
config interface 'lan'
option ifname 'eth0'
option type 'bridge'
option proto 'dhcp'
option ipaddr '192.168.1.1'
option netmask '255.255.255.0'
option hostname 'tl-mr3040'
option ip6assign '60'
config interface 'mesh'
option ifname 'adhoc0'
option mtu '1528'
option proto 'batadv'
option mesh 'bat0'
/etc/config/wireless
config wifi-device 'radio0'
option type 'mac80211'
option channel '11'
option hwmode '11ng'
option path 'platform/ar933x_wmac'
option htmode 'HT20'
list ht_capab 'SHORT-GI-20'
list ht_capab 'SHORT-GI-40'
list ht_capab 'RX-STBC1'
list ht_capab 'DSSS_CCK-40'
option disabled '0'
config wifi-iface 'wmesh'
option device 'radio0'
option ifname 'adhoc0'
option network 'mesh'
option encryption 'none'
option mode 'adhoc'
option bssid '02:BA:00:00:00:01'
option ssid 'meshfx@hackeriet'
/etc/config/batman-adv
config 'mesh' 'bat0'
option interfaces 'adhoc0'
option 'aggregated_ogms'
option 'ap_isolation'
option 'bonding'
option 'fragmentation'
option 'gw_bandwidth'
option 'gw_mode'
option 'gw_sel_class'
option 'log_level'
option 'orig_interval'
option 'vis_mode'
option 'bridge_loop_avoidance'
option 'distributed_arp_table'
option 'network_coding'
option 'hop_penalty'
# yet another batX instance
# config 'mesh' 'bat5'
# option 'interfaces' 'second_mesh'
The mesh node is now operational. I have yet to test its range, but I hope it is good. I have not yet tested the TP-Link 3600 box still wrapped up in plastic.