---
name: "if_ef"
section: "4"
platform: "linux"
package: "freebsd-manpages"
version: "6.0-5"
release: "Debian 4.0 (Etch)"
platforms: ["linux"]
url: "https://new.carta.tech/if_ef"
---

# if\_ef(4)

pseudo-device driver providing support for multiple Ethernet frame types

## NAME

**ef** – pseudo-device driver providing support for multiple Ethernet frame types

## SYNOPSIS

**device ef**

## DESCRIPTION

The **ef** pseudo-device driver clones each Ethernet type device with four additional interfaces. Each of them is capable to send or receive only one predefined frame type.

Names for the new interfaces are created by adding a *fN* suffix to an existing device name. Where *N* is a device unit which can have one of the following values:

```
0     interface with an Ethernet_II frame
1     interface with a Novell Ethernet_802.3 frame
2     interface with an Ethernet_802.2 frame
3     interface with an Ethernet_802.2/SNAP frame support.
```

For example, device *ed0* will be populated with four devices: *ed0f0*, *ed0f1*, *ed0f2* and *ed0f3*.

After that, each device can be configured as usual:

```
# ifconfig ed0f1 ipx 0x105
```

This will configure IPX protocol with network number *0x105* and *Ethernet\_802.3* frame type.

Please note that it is impossible to configure the IPX protocol on the parent *ed0* device after the *if\_ef.ko* driver has been loaded.

If the parent interface is not configured for any other protocol (IP for example), subinterfaces will not function. To avoid that, the parent interface should be manually marked as “up”:

```
# ifconfig ed0 up
```

## EXAMPLES

The **ef** driver can be loaded via the [loader.conf(5)](/loader.conf/5.md) file:

```
if_ef_load="YES"
```

In this case, ordinary interface configuration commands can be used in the [rc.conf(5)](/rc.conf/5.md) file:

```
network_interfaces="ed2 lo0 tun0 ed2f0 ed2f1"
```

```
ifconfig_ed2f0_ipx="ipx 0x101"
```

```
ifconfig_ed2f1_ipx="ipx 0x102"
```

## DIAGNOSTICS

None.

## CAVEATS

Avoid to configure the parent Ethernet device for the IPX protocol, after the **ef** driver is loaded.

## SEE ALSO

[ipx(3)](/ipx/3.md), [ifconfig(8)](/ifconfig/8.md)

## AUTHORS

Boris Popov ⟨bp@FreeBSD.org⟩.