---
name: "interfaces-batman"
section: "5"
platform: "linux"
package: "ifupdown-ng"
version: "0.12.1-7"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/interfaces-batman"
---

# interfaces-batman(5)

B.A.T.M.A.N. adv. extensions for the interfaces(5) file format

## NAME

**interfaces-batman** - B.A.T.M.A.N. adv. extensions for the [interfaces(5)](/interfaces/5.md) file format

## DESCRIPTION

Better Approach To Mobile Ad-Hoc Networking (B.A.T.M.A.N.) advanced is a mesh protocol which provides an Ethernet overlay network over an Ethernet underlay. The overlay interface is called *meshif* whereas underlay interfaces are called *hardif*.

It's supported in the Linux kernel and thus available in many Linux environments. The ifupdown-ng exectuor relies on the **batctl** tool being installed. Support for setting interface based hop-penalties required Linux Kernel 5.8 or later.

B.A.T.M.A.N. adv. adds 30-60 bytes of encapsulation overhead depending on wether netword coding is activated or not. This should be taken into consideration when setting up overlay networks, particularly on underlay networks with a conventional 1500 byte MTU.

See https://www.open-mesh.org/projects/open-mesh/wiki for more details and updates.

The following options allow to set up B.A.T.M.A.N. adv. interfaces.

## BATMAN-RELATED OPTIONS

**batman-ifaces** *list of interfaces*

Specifies the underlay interfaces (hardifs) which should be configured for the B.A.T.M.A.N. adv. meshif defined within the iface stanza.

**batman-hop-penalty** *hop-penalty*

The *hop-penalty* defines the cost of traversing a node or an interface. The *hop-penalty* is a numeric value between 0 and 255. Historically a *hop-penalty* could only be set on a meshif, since B.A.T.M.A.N adv. v2020.3 (included in Kernel 5.8) it can also be set on a per-interfaces (hardif) basis.

**batman-gw-mode** *gw-mode*

Denotes the gateway mode which controls the role this node will play within this B.A.T.M.A.N. adv. instance. The mode can be *off*, *client*, or *server*.

**batman-distributed-arp-table** *mode*

Activates or deactivates the Distributed ARP table (DAT) within this B.A.T.M.A.N. adv. instance. Valid values are *enable* and *disable*.

**batman-multicast-mode** *mode*

Activates or deactivates the multicast mode of this B.A.T.M.A.N. adv. instance. Valid values are *enable* and *disable*.

## EXAMPLES

A B.A.T.M.A.N. adv. *meshif*:

```
auto bat-pad-cty
iface bat-pad-cty
	batman-ifaces dummy-pad-cty vlan1234
	batman-hop-penalty 5
	#
	hwaddress f2:00:c1:01:00:00
	mtu 1500
```

A B.A.T.M.A.N. adv. member interfaces (*hardif*):

```
auto vlan1234
iface vlan1234
	mtu 1560
	batman-hop-penalty 10
```

## SEE ALSO

[**batctl**(8)](/batctl/8.md)

## AUTHORS

Maximilian Wilhelm \<max@sdn.clinic\>