---
name: "esi"
section: "8"
platform: "linux"
package: "linux-atm"
version: "2.5.2-9"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/esi"
---

# esi(8)

get or set the end system identifier (ESI)

## NAME

esi - get or set the end system identifier (ESI)

## SYNOPSIS

**esi** \[***itf***\]\
 **esi** \[**-f**\] *esi* \[***itf***\]\
 **esi** **-V**

## DESCRIPTION

**esi** is used to show or set the end system identifier (ESI, a unique six-byte number corresponding to the MAC address of LAN technologies like Ethernet) of an ATM interface. If the interface number *itf* is omitted, interface 0 is used by default. The *esi* argument is a string of twelve hex digits.

Only the ESI stored in the kernel is accessed; **esi** does not change the ESI stored on the NIC. If a non-zero ESI is already set on an interface, the **-f** option has to be used to overwrite it.

Note that ESI changes are not automatically propagated throughout the system, e.g. to **ilmid**. **esi** should therefore be used early during system initialization.

## OPTIONS

- **-f**

  force overwriting an existing ESI.

- **-V**

  print version number of **esi** on standard output and exit.

## AUTHOR

Werner Almesberger, EPFL ICA \<Werner.Almesberger@epfl.ch\>

## SEE ALSO

[ilmid(8)](/ilmid/8.md)