Table of Contents:
Please take note:
This is the first page you will see when accessing http://localnode:8080/ or http://your-node-name:8080/. The top bar displays the node name and also a tactical name if one has been assigned. For more about tactical names see the Basic Setup section.
Below the name bar there will be a few control buttons. Some of these buttons may not be available depending on the current configuration:
The left column contains the details of the network interfaces used on this node, the default gateway if one is available, and the IP address and name (if known) of the device accessing this page.
The right column contains the signal strength reading and other attributes of your node. The Signal/Noise/Ratio is a reading of the WiFi signal strength in dBm, and it is available only when the node is in a Mesh or Client configuration. The Auto button will take you to an automatically refreshing display of the current signal strength and an average of the last 20 readings. This is provided as an aid to assist in antenna aiming. It is of no use until another node is visible, so it is best used a a fine-tuning tool. Also, this reading is of little use if your node can directly see more than one other node. In this case you should temporarily change the wireless SSID of the two nodes you are aiming antennas for so that the other visible nodes will be excluded from this reading. Just remember to change the SSID back when you are finished. Note that the use of the Auto feature will negatively impact the mesh performance of the node it is running on so it is best used for short periods of time while aiming an antenna. For the best results it should be accessed from the LAN side of your local node. Running this page on a remote node will be less responsive due to the mesh performance degradation.
The system time is kept in UTC and begins at midnight on Jan 1, 2000. There is no internal battery or real time clock so the time will reset every time the node is booted. If an internet connection becomes available the internal NTP (network time protocol) client will connect with an internet time server and the time will be kept in sync with atomic time for as long as the internet connection is available.
The uptime shows how long the node has been running since its last boot, and the load average is the average number of processes that have been running for the last 1, 5, and 15 minutes. The load average will typically be less than 1 for each time slot.
Free space tells you how much space is available on local storage devices. Flash is the internal non-volatile storage where the operating system, configuration files, and software packages are kept. /tmp is a filesystem in RAM that stores the current state information and various temporary files. Memory is the amount of RAM available for running processes.
The Mesh Status page lists AREDN Mesh Nodes, link quality information, and the services advertised on the Mesh. There are 3 sections:
Link Quality (LQ) is the % of packets received from the Neighbor in the OLSR mesh routing protocol from the perspective of the Local Host. OLSR packets are exchanging routing, advertised services, and other information and include a sequence number with each packet to determine missing packets to characterize the quality of the link.
Neighbor Link Quality (NLQ) is the % of packets the Neighbor received from the perspective of the Local Host in the OLSR mesh routing protocol. The NLQ is the LQ from the Neighbor's perspective.
Expected Transmissions (ETX) is a Bernoulli statistic of how many packets must be transmitted to successfully receive the round trip acknowledgement between Neighbor nodes and is calculated with this formula: ETX = 1/(LQ*NLQ). Between multiple hop nodes, this is calculated by adding up the ETX for each single hop. "1" is a perfect RF link between Neighbors. A DtDLink is fixed at ETX="0.1" for packets over a cat5 cable. OLSR on a Mesh Node selects the Neighbor to send traffic to based on the lowest cost ETX path towards the final destination Node.
ETX should be interpreted with care. From a quality perspective, the ETX for Remote Nodes is not an end-to-end metric in the same way as adjacent neighbors. For example, 2 nodes that are 5 hops apart with zero packet loss between them is characterized with an ETX=5. A single hop with ETX=5 (LQ and NLQ is ~45%) will stream poor quality video, if usable at all, given the packet loss. A 5 hop route between nodes with ETX=5 will deliver smooth streaming quality video.
Transmitted Mbps (TxMbps) is calculated with the formula (TxMbps = rate * EWMA) where rate is the 802.11 data rate in use by the transmitter and EWMA is the Exponetially Weighted Moving Average or the current time weighted chance that a packet at this rate will reach the remote station. If no traffic is being routed to the Neigbor, this value may be '0' until data is available to measure and determine the optimal settings. For further details: Rate Control Algorithm
"(wan)" next to a Mesh Node indicates the node is an Advertised Gateway. Typically this is to the internet, but may also be an isolated network.
"(dtd)" next to a Mesh Node indicates the path to a Neighbor is a cat5 cable. The Neighbor may be listed twice if both an RF and DtDLink path exists. The DtDLink path is always assigned an ETX of "0.1".
This is where the basic networking settings are made for the node. Because of the way AREDN™ is designed you generally will not need to change any of the settings on this page other than the node name/type and password.Do not change any of the network settings unless you fully understand how the mesh works and why the default is not suitable for your application. One reason AREDN™ exists is to eliminate, as much as possible, the need to manually configure the network.
The buttons on this page work as follows:
Node Name sets the hostname for the node. Hostnames can contain up to 63 letters, numbers, and dashes, but cannot begin or end with a dash. Underscores, spaces, or any other characters are not allowed. Hostnames are not case sensitive, but the case will be preserved.
As ham radio operators there are other requirements we must follow, namely identification of all transmitting stations. This hostname is beaconed automatically by the node every five minutes, so the hostname must contain your callsign. Recommended hostnames follow the (callsign)-(name) format, such as ad5oo-mobile or ad5oo-1. This is similar to the MYCALL setting you would give a packet TNC, but without the 0-15 restriction for the name part.
It is here that you can also set a tactical name for your node. A tactical name is just another name that your node is known by. If you are familiar with DNS records, this serves a purpose similar to a CNAME record. This is helpful in an emergency deployment situation where if for example several Red Cross shelters are being linked. In addition to the normal hostname you can give each node a tactical name such as shelter1, shelter2, shelter-north, etc. Tactical names have the same restrictions as hostnames, and are accessible through DNS like the main node names are.
To set a tactical name, put a slash after the the node name then give the tactical name. For example, "ad5oo-1/shelter5".
Node Type sets the operational mode of the device as follows:
Node Type sets the operational mode of the node. For our purposes it will be set to Mesh Node, but if needed it can also be set to one of the other modes, to be described at a later time.
The one mode I will mention is called Mesh Access Point. It is a configuration meant to be used to give standard wireless access to the LAN port of a mesh node. This is to be used on a second router whose LAN port is connected with the LAN port of a mesh node. When running a router in this mode it does not use OLSR and as a result its hostname is not available to the mesh. It can be accessed from the LAN by its IP address which by default is 172.27.0.2. Like the name "localnode", an automatically generated name exists called "localap" which is set to the localnode address plus one, but only when the node is operating in the default NAT mode.
Password is where you set the administration password for the node. It needs to be entered again in the Retype Password box to help ensure its accuracy. It is not necessary to enter a password unless you want to change its value, and the first time the node is configured it is required that you change the password. Note that these passwords entries are NOT encrypted in transit, so this is best done from a direct wired connection to the node.
The WiFi, LAN, and WAN boxes are where the details of each of these network interfaces are set.
In the WiFi box there are settings shown as being Active Settings. These settings can be changed without rebooting the node by clicking the Apply button, but unless they are saved they will revert to the previously saved values after a reboot.
The Rx Antenna and Tx Antenna settings have been removed from current builds. The hardware handles antenna selection automatically in the backend without need for configuration.
As always a dummy load on unused RF ports is recommended to keep out physical contaminants and to avoid EMI/RFI interference.
The Power setting controls the max power the unit may output. The node may decrease its power output as it enters higher speed data rates to maintain a linear spectrum. Some devices may have max power levels that change based on what channel/frequency the hardware is operating on, in this case the max level will change when you save the settings and will be capped at the max level supported by the hardware for that frequency.
The Distance setting adjusts the packet retry timer to account for stations that are very far away, presumably about 300 meters or more. The value should be set to the distance in meters to the farthest node that you expect to communicate with. A value of 0 sets it to automatic, which may or may not be suitable for your application. The only way to know is to experiment with it. Changes smaller than 150 meters do not affect the settings, so the value entered here will be reduced to the smallest multiple of 150 that produces the same effect.
The LAN box allows you to set the LAN IP Address of the node and the address range of the DHCP server, and these should be self explanatory. The LAN Mode is described in the next section.
The Disable Default Route checkbox will cause the node to not advertise that it should be chosen as the default route. This means that computers plugged into the node will not try and route to the internet or other networks via the mesh node and will only try and use the mesh node for the 10.0.0.0/8 and 172.16.0.0/12 "mesh" network ranges. You will not be able to access the internet, even if your node has internet available on its wan port with this setting checked. This also applies to internet available over the mesh. Use this only if you know what a default route is and you need to be connected to two networks at once such as wired to the mesh, and WiFi to a local served agency network.
The WAN box contains the settings used to connect with an upstream network, usually an internet connection. The DNS servers are set by default to the Google DNS servers and should not be changed under normal circumstances. More and more ISP's are adopting the "helpful" but broken behavior of taking you to an ISP generated web page if you incorrectly type in a URL or if the host you are trying to reach no longer exists. The proper behavior is for your browser to be able to detect these error conditions and report them accordingly. Google follows the rules and allows for the proper operation of the network.
When the WAN protocol is set to disabled you have the option of using a default gateway on the LAN. Integrating an existing LAN with a mesh node LAN is an expert level undertaking and there are far too many considerations to be covered here.
The other option in the WAN box is the Mesh Gateway. This is an advanced configuration option.
When a node has internet access from either the WAN or LAN, that access is available to the node itself and to any computer connected to the LAN port. When the Mesh Gateway is enabled this node will gate(route) traffic from the mesh onto this network and the internet. By default it is disabled, so consider carefully your intentions for enabling it. AREDN™ is an FCC Part 97 amateur radio computer network, so be sure that any internet traffic that will be sent over radio needs to comply with Part 97 rules. If you just want local wireless internet access, consider using a standard Part 15 compliant access point instead of the Mesh Gateway function.
The default mode is called 5 Host Direct mode and in this mode every host on the LAN has direct access to and from the mesh. The LAN shares the same address space as the mesh. Port forwarding is not needed because NAT is not used, and there is no firewall in between the LAN and the mesh. This mode was created because some services do not work well (or at all) through NAT, and to reduce the amount of manual configuration needed to provide services to the mesh.
The mesh address space is automatically managed, so in Direct mode the LAN is not user configurable. Those of you familiar with setting up commercial ISP access with static IP addresses should already be comfortable with this mode. Like commercial ISP access, you cannot decide for yourself what the network parameters are. You have to use the parameters which are given to you. But unlike most commercial ISP access there is a DHCP server available on the mesh node to configure the hosts that are attached to the LAN.
The only configurable option available in Direct mode is the size of the LAN subnet which can accommodate either 1, 5, or 13 LAN hosts. The one host subnet can be useful for either a single server or a commercial grade router using its own NAT which is capable of more advanced routing functions than those available from a mesh node.
It is important to not use a subnet larger than is necessary because the chances of an IP address conflict on the mesh increase with the size of the subnet. The LAN subnet parameters are automatically generated and depend on the IP address of the WiFi interface. If a conflict does occur it can be fixed by changing the WiFi IP address.
The other LAN Mode is NAT, which stands for Network Address Translation. In this mode the LAN is isolated from the mesh and all outgoing traffic has its source address modified to be the WiFi address of the mesh node. This is the same way that most routers use an internet connection, and all services provided by computers on the LAN can only be accessed through port forwarding rules. A single DMZ server can be set up to accept all incoming traffic that is not already handled by other rules or by the node itself.
If you choose, you can specify your latitude, longitude, and gridsquare for location purposes. The lat/lon values should be in decimal format (ex. 30.444522 and -95.111234).
You may set the timezone where the node is located as well as setting the NTP server that the node will connect to. A "Save Changes" button click IS required for timezone and NTS server settings, as well as a subsequent reboot.
When a device is configured in Mesh Access Point mode it is essentially 'transparent'. You are going through the device to reach a mesh node, and there is no need to get to the device unless you wish to change its configuration. When the time comes to reconfigure a device in this mode be aware that it is not running its own DHCP server because that is the job of the mesh node it is connected to. You will need some other way to configure your computer's network interface. There are two ways to do this:
In this mode the default IP address on the LAN port is 172.27.0.2. After one of the above steps you should be able to send your browser to http://172.27.0.2:8080/. If you used automatic configuration you should also be able to go to http://localap:8080/. Like the name "localnode", an automatically generated name exists called "localap" which is set to the localnode address plus one, but only when the node LAN mode is set to NAT. If you changed the default IP address of a Mesh Access Point you will have to modify these instructions accordingly.
The buttons on this page works as follows:
The way this page works depends on whether the LAN is operating in NAT mode or Direct mode. First we will cover NAT mode, where hosts on the LAN are insulated by a firewall and NAT from both the WiFi and WAN interfaces. This makes them inaccessible from either of these interfaces unless Port Forwarding is set up. Here are some common ports:
So then what is port forwarding? Port forwarding is taking an inbound connection to a port from the WiFi or WAN interface and forwarding it to an IP address on the LAN. The port number need not be the same. If you have hosts on the LAN that provide services you want to make available to the mesh all it takes is a Port Forwarding rule to make that happen.
If you want to forward a range of ports, the Outside Port will accept a range in the form "2000-3000". Use a hyphen to separate the low and high values. When doing this, set the Inside Port to the low value of the port range. When forwarding a port range the outside and inside ports must be the same, moving them will not work.
If you want to forward every port that is not already in use to a single computer on the LAN, choose that computer's IP Address from the DMZ Server selector. There can be only one DMZ Server. Be aware that this bypasses the firewall in the node, so this computer should be running its own firewall to prevent unauthorized access.
On the LAN of a mesh node called ad5oo-mobile is an IP camera that is running its own web server. The address of that camera is 172.27.0.240. I want to make that camera available to everyone on the mesh so I set up a port forwarding rule on the WiFi interface whose outside port is 8100, IP address is 172.27.0.240, and inside port is 80. This takes all connections to port 8100 on ad5oo-mobile and redirects them to port 80 on 172.27.0.240. In a web browser on a computer connected to a different node you would go to http://ad5oo-mobile:8100 and would be connected to the IP camera.
Note that port forwarding to an FTP server, which uses both ports 20 and 21, can be done with a single rule using port 21 if the ftp client is capable of using passive ftp mode. Web browsers are able to do this and handle ftp downloads quite nicely.
When you want to let others know about services you are providing, the Advertised Services will appear on the Mesh Status page of all other nodes on the mesh. All advertised services need a name, and no services can be advertised until at least one port forwarding rule or a DMZ server has been defined.
If the service is one that is accessible through a web browser, such as a web or ftp server, you can make the name appear as a clickable link by checking the Link box. All links need two parameters: a protocol and a port number. Web servers use the http protocol and ftp servers use the ftp protocol. Other servers may use other protocols. The port number should be the one used as the Outside Port in the forwarding rule through which the service can be accessed. In the last field you can enter an optional link suffix to give the link a more specific path if needed, such as the name of a specific page on a web server, or a directory or file on an ftp server.
If you are providing services to the mesh from hosts on the LAN you will want to either override or make permanent the automatically assigned IP address for that host. The DHCP Reservations section is where you do that. In order for port forwarding to work, the IP address must match that of the host being forwarded to. If it is currently attached and has been set up by DHCP it will be listed under Current DHCP Leases. If you click the Add button next to the lease it will be added to the DHCP Reservations list. You can leave the information as it is or edit it to suit your needs. You can also enter your own information into the blank slots under DHCP Reservations and click Add to create your own entry.
For each of the sections on this page, simply entering information into the fields next to the Add buttons is not enough. The settings are not entered until the Add button is clicked. Before saving changes the Add fields must be either added or cleared.
Direct Mode Operation
When the LAN is operating in Direct mode both this page and the mesh work a little differently. Since in Direct mode the LAN hosts are accessed directly from the mesh and no port forwarding is involved, the advertised services are based upon which LAN hosts exist, and this is determined by the DHCP Address Reservations that are defined. After the DHCP Reservations have been made, services can be advertised in the same way as before with the additional requirement of selecting the name of the host that is providing the service.
Another difference in Direct mode is that the hostnames used in DHCP Reservations are also advertised to the mesh and therefore must be unique on the mesh. So, "webserver" would be perfectly suitable for a service name, but a very poor choice for a hostname because there can be only one host with this name on the entire mesh. Just as you used your callsign in the hostname for the node, it would also be a good idea to use it in DHCP Reservation hostnames. Therefore, "ad5oo-webserver" is a good choice of hostname as it is unique and only the callsign holder needs to keep track of the hostnames he has assigned himself.
The hostnames being discussed here are those that are defined in the DHCP Reservations and available to the mesh, not those that the LAN hosts call themselves. While it can be convenient for them to be the same, there is no reason that they must be. For example, the name "ad5oo-webserver" used above can be the name on the mesh for a host that calls itself "skywalker". But be aware that if this host is in fact a webserver, the webserver configuration should use the name "ad5oo-webserver" because the name "skywalker" will not be known on the mesh and any pages the webserver generates itself such as error pages may use the "skywalker" name.
There are two considerations to keep in mind regarding the size of the subnet chosen for the LAN. First, when using a one host subnet, the DHCP Reservation used for that single host will prevent any other host from receiving a DHCP lease. So if for some reason the original host is not connected to the LAN and you need to get back in to the node to reconfigure it, the easiest way is to access it from a different node on the mesh.
Second, if the node is already in Direct mode and you intend to reduce the size of the LAN subnet, you should first remove the DHCP Reservations that will fall outside of the address range of the smaller subnet. Note that the automatically assigned network address will change if the subnet size is changed, and that internally the DHCP Reservations are stored as offsets from the network address, so address reservations which fall within the new subnet size will be translated into the new subnet address space.
Firmware Update is how new firmware is installed on the node. If you have a firmware image on your computer, click the Browse button and select the firmware file to upload. Click Upload and the file will be uploaded and installed. If the node has internet access (either from the WAN port or from the mesh) you can use the Download Firmware option. Click Refresh to get the list of available images. Select the image to download, clickDownload, and wait for the firmware to download and be installed.
A new feature in the 0.4.0 firmware is the ability to install firmware patches. This means that updated files can be installed directly on the node without having to replace the entire firmware. Except in cases where the patch contains updated configuration files, patches can be installed while preserving the existing node configuration. However, certain patches will require that the node be rebooted to take effect, and this will happen automatically when it is needed.
Package Management allows you to install and remove software packages on the node. Upload Package allows you to install a package file from your computer. Download Package allows you do retrieve a package over the internet from the AREDN™ website. Clicking Refresh will populate the list of packages available for download, but don't do this frivolously. The package information database gets stored locally and will use about 100KB of space in flash memory. The average user will probably never have to use this function.
The Remove Package list shows all packages on the node. Selecting a package and clicking Remove will remove the package. You will only be able to remove packages that you have installed. All installed packages are shown but the set that comes pre-installed is necessary for proper operation of the node and they cannot be deleted.
Authorized SSH Keys are useful for both developers and anyone managing a "fleet" of nodes. It allows connecting to a node via ssh without having to know the password. For developers, it also allows you to easily scp an updated file to the node without having to reinstall the firmware.
To generate a key on a Linux system, issue the command "ssh-keygen -t rsa" and hit enter at all the prompts to accept the defaults. It creates a file called ~/.ssh/id_rsa.pub, which is the file you upload to install the key on the node. If you want to remove a key just select it and click the Remove button.
For fleet managers, having an authorized key installed is the best way gain access to a node for which you do not know the password. If you want to set the password to "abc", simply ssh to the node and run "setpasswd abc", then reboot. If you don't have an authorized key installed, the only way in is to use Failsafe Mode as described in the appendix.
Failsafe Mode is a method of booting a node into a minimal configuration which allows you to log in and undo a change that may have broken the node or to change a forgotten password without having an authorized ssh key in place. Since fixing a node is an advanced topic suitable only for experts, here I will just cover how to change a password.
How to use failsafe mode:
Now power cycle the node and it should accept your new password.
If the device has a reset button you may instead press and hold the reset button for 15 seconds which will cause the unit to behave as if it had just been flashed with the AREDN™ firmware.
You would need to go through the node settings again just as if it was the first time installing the AREDN™ firmware on the node.
Your router is a brick. It does not come up normally and you are not able to log in by any method. All is not lost, read on to see how to use the built in failsafe method of installing firmware. If this method does not work, you will have to resort to a JTAG install. Good luck with that. See www.openwrt.org for information on the JTAG method.
The CFE (Common Firmware Environment - the bootloader) has the ability to receive a firmware image using tftp (the trivial file transfer protocol) and write it to flash. When the nvram variable boot_wait is set to on, (as it will be after the mesh firmware is installed at least once) there is a three second window where it listens for tftp packets. If it hears them, it will load the firmware into ram, write it to flash, then reboot. If the CFE detects some problem with the firmware already on the flash (such as an interrupted flash write) and is unable to boot, it should wait indefinitely for a tftp transfer. At this point I'm not sure what the CFE behavior is when boot_wait is set to off. I believe it still listens for tftp packets, but the window of opportunity is one second or less.
Here is a Linux script you can use to send tftp attempts to 192.168.1.1 once every second for an hour or until the upload succeeds. It sets the tftp trace mode so that you can see every attempt and also see when the transfer has happened and whether or not it succeeded.
#!/bin/sh if [ -z "$1" ]; then echo "usage: $0 <image file>" exit 1 fi file=$1 cd `dirname $file` tftp 192.168.1.1 << END bin rexmt 1 trace on timeout 3600 put `basename $file` code.bin END
To reflash a device with this script, you will need to have your computer's ethernet port connected to the LAN port on the router, with the IP address statically set to 192.168.1.2, netmask 255.255.255.0. Run the script with the image name as an argument. The .trx file will not work here, you need the .bin file specific to your model of router.
Once per second you will see messages like this:
Now power cycle the router. If the above messages continue and the router continues to boot, it missed the window. This is not unusual. Power cycle the router again and repeat the process until you see messages like this:
sent DATA received ACK sent DATA received ACK
After that the flash write begins, then the router will reboot.
During this process one thing that may get in the way is network management software that many modern operating systems use to automatically control your ethernet port. It becomes a problem when power cycling the router causes the network manager to enable and disable the ethernet port because it sees the connection disappearing and reappearing.
One way around this is to disable the network manager and take manual control of your network interfaces if you are able to do that. Otherwise it can be avoided by using another ethernet switch which both your computer and the router receiving the firmware are connected to. You should be able to use the LAN switch on the back of another mesh node if a separate switch is not available.