Bundle layer commands

Mpd 3.18 User Manual : Configuring Mpd : Bundle layer commands
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## 4.2. Bundle layer commands

This chapter describes commands that configure the bundle layer. All of these commands (except `new`) apply to the currently active bundle, i.e., the bundle shown at the command line prompt.

`new` [`-i iface` ]`bundle link1` [`link2` ... ]

  This command creates a new bundle named `bundle`. The bundle will be associated with system interface `iface`, which should be the name of a netgraph interface, i.e., `ng0`, `ng1`, etc. If an interface is specified but does not exist yet, mpd will create it (and any lower numbered `ng*` interfaces as well). If no `iface` is specified, mpd will create a new one. Specifying an interface explicitly is advised, as otherwise a new interface will be created on your system every time mpd is invoked.

  The links that constitute the bundle are created and named `link1`, `link2`, etc. For each link, there must be a corresponding entry with the same name (i.e., label) in `mpd.links`. This entry must at the very least define the type of the link (via the `set link type` command).

`set bundle period seconds
set bundle hiwat percent
set bundle lowat percent
set bundle min-con seconds
set bundle min-dis seconds`

  These commands are only meaningful when bandwidth management is enabled. Mpd will attempt to bring up a new link or take down an existing link when the utilization goes above `hiwat` or below `lowat` percent, respectively. The utilization is sampled every `period` divided by 6 seconds, and is averaged over the past `period` seconds.

  Mpd will not attempt to reconnect a link unless it has been disconnected for at least `min-dis` seconds. Similarly, mpd will not bring down a link unless it has stayed connected for at least `min-con` seconds. These latter two parameters help prevent oscillations, but cause slower response time.

`set bundle authname login`

  This command sets the authentication login name associated with the bundle (in multi-link PPP, though each link is authenticated individually, they all must use the same login name). The `login` must have a corresponding entry in `mpd.secrets`. The `login` and password are used when the peer requires us to authenticate ourselves.

`set bundle password password`

  This command is normally not necessary. It causes mpd to not lookup the password corresponding to `login` in `mpd.secrets`, but rather to use `password` instead. If you're too lazy to set up `mpd.secrets` and are only dialing out, you can use this command instead.

`set bundle retry seconds`

  This sets the finite state machine (FSM) retry interval for all FSM's on this bundle. The default is 2 seconds. This command should only be used in exceptional situations, such as doing PPP over high-latency satellite links.

`set bundle accept option ...
set bundle deny option ...
set bundle enable option ...
set bundle disable option ...
set bundle yes option ...
set bundle no option ...`

  These commands configure various bundle options. Most options are bi-directional in that they can be independently enabled and disabled in each direction.

  The `enable` and `disable` commands determine whether we want the corresponding option. The `accept` and `deny` commands determine whether we will allow the peer to request the corresponding option.

  The `yes` command is the same as `enable` and `accept`. The `no` command is the same as `disable` and `deny`.

The options available at the bundle layer are:

`bw-manage`

  This command enables bandwidth management, in which mpd attempts to dynamically adjust the number of connected links depending on the traffic load.

  The proper functioning of bandwidth management depends on the correct latency and bandwidth information configured for each link; see the `set link latency` and `set link bandwidth` commands.

  The default for this option is off -- mpd connects the links ``all or none.''

`multilink`

  This command enables multi-link PPP on the bundle. This option is required in both directions if there is more than one link in the bundle. However, multi-link PPP is sometimes useful on single links when the link MTU is low; multi-link PPP allows arbitrarily long packets to go over a link in fragments.

  This option defaults to `enable` and `accept` unless there is only one link in the bundle, in which case it defaults to `disable` and `deny` (i.e., normal non-multilink PPP).

`shortseq`

  This option is only meaningful if multi-link PPP is negotiated. It proscribes shorter multi-link fragment headers, saving two bytes on every frame. It defaults to `enable` and `accept`.

`compression`

  When compression support is compiled into mpd, this option must be enabled in order to activate it.

`encryption`

  When encryption support is compiled into mpd, this option must be enabled in order to activate it.

`crypt-reqd`

  Require encryption. When encryption support is compiled into mpd, this option causes mpd to drop the link if encryption cannot be succesfully negotiated in both directions. This means in effect, ``use encryption or don't connect at all.''

`round-robin`

  When multilink PPP is enabled and there are two or more links connected, this option enables round robin packet scheduling across the links. That is, instead of breaking each packet into fragments and delivering the individual fragments over all the links in the bundle, each packet is delivered whole over single link. The link is chosen by rotating in round-robin fashion over all the links in the bundle.

  This option normally would result in higher latency and possible delays due to TCP packets being received out of order; however, it may help in certain situations of high packet loss or broken peer equipment.

  The default for this option is off.

`noretry`

  This tells mpd to not attempt to reconnect a bundle whose last link has closed. This is needed for dialin-only bundles, where mpd doesn't know how to initiate an outgoing connection.

`radius-auth`

  Enable authentication via RADIUS. All authentication methods are supported (PAP, CHAP, MS-CHAPv1, MS-CHAPv2). When using IAS as RADIUS server you can not use CHAP, because CHAP needs a plaintext password on the server, and Windows servers only store the NT-HASH. Password changing is currently not supported.

`radius-fallback`

  This option is only relevant when `radius-auth` is enabled. If disabled, authentication is only attempted via RADIUS. Otherwise, if authentication via RADIUS fails, mpd will attempt to authenticate using the traditional method using `mpd.secrets`.

`radius-acct`

  Enable accounting via RADIUS. Accounting is implemented at bundle-level (in BundJoin() and BundLeave()). Accounting is done per link. There are some minor problems:

  - If user enters `quit` on the console, Account-stop will not be sent.
  - If CCP fails but is required, Account-start and Account-stop are sent, but they shouldn't be.

  Note: Its possible to use RADIUS-accounting without RADIUS-authentication.

  The following attributes are set when doing accounting requests:

  `RAD_FRAMED_IP_ADDRESS
  RAD_ACCT_STATUS_TYPE
  RAD_ACCT_SESSION_ID
  RAD_ACCT_MULTI_SESSION_ID
  RAD_USER_NAME
  RAD_ACCT_LINK_COUNT
  RAD_ACCT_AUTHENTIC
  RAD_ACCT_TERMINATE_CAUSE
  RAD_ACCT_INPUT_OCTETS
  RAD_ACCT_INPUT_PACKETS
  RAD_ACCT_OUTPUT_OCTETS
  RAD_ACCT_OUTPUT_PACKETS
  RAD_ACCT_INPUT_GIGAWORDS
  RAD_ACCT_OUTPUT_GIGAWORDS
  RAD_ACCT_SESSION_TIME`

`tcp-wrapper`

  With this option mpd uses `/etc/hosts.allow` everytime a connection is made from the client. This is useful if you would like to restrict access to mpd. This option affects all TCP connections, including PPTP and the TCP device layer.

  The console is also affected, but a bug requires this option to be set consistently on all bundles for it to work reliably.

`max-logins num`

  Limit the max. amount of concurrent logins with the same username. If set to zero, then this feature is disabled.

Mpd 3.18 User Manual : Configuring Mpd : Bundle layer commands
Previous: General mpd commands
Next: Interface layer commands