Working with the vis server output¶
This artcile is for those that intend to write their own visualization tool, combine the vis output with a map or want to understand the vis server output for another reason. If you want to setup the vis server for the batmand have a look at this article or for BATMAN-Advanced at this one.
Here is a sample output from the vis server in the dot draw format. Newer vis versions offer alternative formats (e.g. JSON) which follow the same rules but use another output style.
digraph topology
{
"5.174.37.225" -> "5.224.160.202"[label="2.13"]
"5.174.37.225" -> "192.168.15.0/24"[label="HNA"]
"5.174.117.226" -> "5.174.37.225"[label="5.00"]
"5.174.117.226" -> "0.0.0.0/0.0.0.0"[label="HNA"]
"5.224.160.202" -> "5.174.37.225"[label="1.28"]
"5.224.160.202" -> "0.0.0.0/0.0.0.0"[label="HNA"]
}
Each "digraph { ... }" block contains a complete dump of the vis servers internal database at a given time. Every line contains the IP address of a batman node, a network it has a relation to and a label. All nodes sending information to the vis server are listed in the first column. If a node is missing you should check whether there is a connection problem.
Batman to batman connection¶
"5.174.37.225" -> "5.224.160.202"[label="2.13"] "5.224.160.202" -> "5.174.37.225"[label="1.28"]
The batman node 5.174.37.225 has a connection towards the batman node 5.224.160.202 with a link quality of "2.13" whereas the 5.224.160.202 has a link quality of "1.28" towards the 5.174.37.225. The connection is listed twice because each node reports it individually which gives you the option of seeing asymetric links if you want to display it.
The link quality gives information how batman evaluates this link. 1.00 means 100% link quality, 2.00 means 50%, 3.00 is 33.3% and 4.00 is 25%, etc. The number tells you how many packets you need to send in order to get a single successful transmission.
While looking at originator tables, debug logs or other batman output you might see different numbers. Due to performance considerations batmand uses its own format (TQ value) to express link quality. Its max value is 255 and goes down to 0 (float operations are quite expensive on embedded devices). The vis server transforms the TQ value into its own format before outputting it.
Internet gateways¶
"5.224.160.202" -> "0.0.0.0/0.0.0.0"[label="HNA"]
The 5.224.160.202 announces a connection to the internet: "0.0.0.0/0.0.0.0" and the HNA label represent gateway functionality in the output.
Announced networks¶
"5.174.37.225" -> "192.168.15.0/24"[label="HNA"]
The 5.174.37.225 announces a connection to the 192.168.15.0/24 network (which does not run batman). All nodes that establish a connection to this network use the 5.174.37.225 as gateway.
Interfaces belonging to one BATMAN-Adv node¶
In BATMAN-Advanced since revision 1424, the subgraphing/cluster feature of the dot-file-format has been added to mark interfaces as belonging to the same originator. Every originator the vis-server found has such an additional subgraph block:
subgraph "cluster_00:11:22:33:44:55" {
"00:11:22:33:44:55" [peripheries=2]
"01:23:45:67:89:AB"
}
In this example the originator '00:11:22:33:44:55' has two active interfaces, "00:11:22:33:44:55" and "01:23:45:67:89:AB". With 'fdp' from the graphviz-tools for instance such interfaces inside of a subgraph would be surrounded by a box. The cluster-prefix is a prerequisite for this tool here to describe the relation between those interfaces and is not a label being visualized. Additionally, the primary interface gets the extra attribute '[peripheries=2]' which is the only interface known to other BATMAN-Nodes, except to direct neighbours (with graphviz, such an interface gets double circled).