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

# ng\_lmi(4)

frame relay LMI protocol netgraph node type

## NAME

**ng\_lmi** – frame relay LMI protocol netgraph node type

## SYNOPSIS

**#include \<sys/types.h\>**

**#include \<netgraph/ng\_lmi.h\>**

## DESCRIPTION

The **lmi** node type performs the frame relay LMI protocol. It supports the ITU Annex A, ANSI Annex D, and Group-of-four LMI types. It also supports auto-detection of the LMI type.

To enable a specific LMI type, connect the corresponding hook (annexA, annexD, or group4) to DLCI 0 or 1023 of a [ng\_frame\_relay(4)](/ng_frame_relay/4.md) node. Typically, Annex A and Annex D live on DLCI 0 while Group-of-four lives on DLCI 1023.

To enable LMI type auto-detection, connect the auto0 hook to DLCI 0 and the auto1023 hook to DLCI 1023. The node will attempt to automatically determine which LMI type is running at the switch, and go into that mode.

Only one fixed LMI type, or auto-detection, can be active at any given time.

The NGM\_LMI\_GET\_STATUS control message can be used at any time to query the current status of the LMI protocol and each DLCI channel. This node also supports the NGM\_TEXT\_STATUS control message.

## HOOKS

This node type supports the following hooks:

- annexA

  ITU Annex A LMI hook.

- annexD

  ANSI Annex D LMI hook.

- group4

  Group-of-four LMI hook.

- auto0

  Auto-detection hook for DLCI 0.

- auto1023

  Auto-detection hook for DLCI 1023.

## CONTROL MESSAGES

This node type supports the generic control messages, plus the following:

- NGM\_LMI\_GET\_STATUS

  This command returns status information in a struct nglmistat:

  ```
  #define NGM_LMI_STAT_ARYSIZE   (1024/8)
  struct nglmistat {
    u_char  proto[12];	/* Active proto (same as hook name) */
    u_char  hook[12];	/* Active hook */
    u_char  fixed;	/* If set to fixed LMI mode */
    u_char  autod;	/* If currently auto-detecting */
    u_char  seen[NGM_LMI_STAT_ARYSIZE];	/* bitmap DLCIs seen */
    u_char  up[NGM_LMI_STAT_ARYSIZE];	/* bitmap DLCIs up */
  };
  ```

- NGM\_TEXT\_STATUS

  This generic message returns is a human-readable version of the node status.

## SHUTDOWN

This node shuts down upon receipt of a NGM\_SHUTDOWN control message, or when all hooks have been disconnected.

## SEE ALSO

[netgraph(4)](/netgraph/4.md), [ng\_frame\_relay(4)](/ng_frame_relay/4.md), [ngctl(8)](/ngctl/8.md) *ANSI T1.617-1991 Annex D*. *ITU-T Q.933 Digital Subscriber Signaling System No. 1 - Signaling Specification for Frame Mode Basic Call Control, Annex A*.

## HISTORY

The **ng\_lmi** node type was implemented in FreeBSD 4.0.

## AUTHORS

Julian Elischer ⟨julian@FreeBSD.org⟩