set ppp

Purpose

Configures or displays Point-to-Point Protocol (PPP) outbound connections.

This command can also be used to enable or disable all mobile connections.

Required permissions

For Digi products with two or more users, to use this command, permissions must be set to set permissions s‑ppp=read to display settings, and set permissions s‑ppp=rw to display and configure settings. See set permissions for details on setting user permissions for commands.

Syntax

Configure PPP connections

set ppp port=range
  [state={enabled|disabled}]
  [auth_method={none|PAP|CHAP|both}]
  [passive={on|off}]
  [remote_address={ip address|negotiated}]
  [local_address={ip address|negotiated}]
  [address_mask=ip address mask]
  [default_gateway={yes|no}]
  [ipcp_dns_enabled={on|off}]
  [protocol_compression={on|off}]
  [address_compression={on|off}]
  [header_compression={on|off}]
  [lcp_keepalive={on|off}]
  [lcp_ka_quiet_time=(10-86400 seconds)]
  [lcp_ka_max_missed_replies={(2-255|0=ignore missed replies)}]
  [asyncmap=hex string]
  [chap_id=chap id]
  [chap_key=chap key]
  [pap_id=pap_id]
  [pap_password=pap password]
  [mru=1500-2048
  [mtu=1500-2048]
  [redial_attempts=attempts]
  [redial_delay=delay]
  [rx_idle_timeout=timeout]
  [tx_idle_timeout=timeout]
  [init_script=chat script]
  [dial_script=chat script]
  [login_script=chat script]
  [n{1-4}=phone_number]
  [proxy_arp={on|off}					
  [device_description=”description text”]

Display PPP settings

set ppp

Enable or disable all mobile connections

Enter this command with no other options specified:

set ppp port=5 state={enabled|disabled}

Options

port=range

The physical interface to which the PPP outbound configuration applies. Required.

state={enabled|disabled}

The state of the interface. The default is disabled.

auth_method={none|PAP|CHAP|both}

Determines whether authentication is required for outbound PPP connections and, if so, what kind.

none

The remote user does not require PPP authentication.

pap

Password Authentication Protocol (PAP) authentication is required.

chap

Challenge Handshake Authentication Protocol (CHAP) authentication is required. CHAP authentication works between two Digi devices. CHAP will be negotiated to PAP for all other connections.

both

Both CHAP and PAP authentication are required.

The default is none.

passive={on|off}

Specifies whether the device server waits for the remote system to begin PPP negotiations, or can initiate PPP negotiations on its own.

Do not set both sides of a PPP connection to passive=on.

on

The device server waits for the remote system to begin PPP negotiations.

off

The device server may initiate PPP negotiations.

The default is off.

remote_address={ip address|negotiated}

The address of the peer at the other end of the outbound PPP connection. Either a specific address or the keyword negotiated can be specified; negotiated means that the address will be accepted from the peer. An IP address of all zeroes is equivalent to specifying the keyword negotiated.

local_address=ip address|negotiated}

The IP address of the local end of the PPP outbound connection. Either a specific address or the keyword negotiated can be specified; negotiated means that the address will be accepted from the peer. An IP address of all zeroes is equivalent to specifying the keyword negotiated.

address_mask=ip address mask

The IP mask to apply to the address specified on the remote address and local address options. When you specify a specific IP address on the remote address and local address options, this option modifies the meaning of the IP address for routing purposes. The default is 255.255.255.255.

default_gateway={yes|no}

Selects whether to use the PPP interface as the default route. The default is no.

ipcp_dns_enabled={on|off}

Enables or disables the IPCP (PPP Internet Protocol Control Protocol) acquisition of DNS IP addresses. This option is enabled by default to preserve prior behavior.

protocol_compression={on|off}

Specifies whether the device server attempts to negotiate protocol compression on PPP connections.

on

The device server attempts to negotiate protocol compression on PPP connections.

off

The device server will not negotiate protocol compression.

The default is on.

address_compression={on|off}

Specifies whether the device server attempts to negotiate address compression on PPP connections.

on

The device server attempts to negotiate address compression.

off

The device server does not attempt to negotiate address compression.

The default is on.

header_compression={on|off}

Specifies whether the device server attempts to negotiate IP protocol header compression on PPP connections. This is commonly referred to as Van Jacobsen (VJ) header compression.

on

The device server attempts to negotiate IP protocol header compression.

off

The device server does not attempt to negotiate IP protocol header compression.

The default is on.

lcp_keepalive={on|off}

Specifies whether the device server sends Link Control Protocol (LCP) echo requests after a “quiet” interval, in order to test the PPP link and/or keep it alive. “Quiet” means not having received any bytes over the PPP link for a specified time interval, which is set by the lcp_ka_quiet_time option. In PPP networks that support LCP echoes, an LCP echo reply is returned by the remote end of the PPP connection.

 

Even if LCP keepalives are disabled in this device (by lcp_keepalive=off), the device will still reply to LCP echo request messages it may receive from the remote side of the PPP connection by sending an LCP echo reply message. But the device itself will not originate any LCP echo request messages.

The options are:

on

The device server sends LCP echo requests after a configurable “quiet” interval, set by the lcp_ka_quiet_time option.

off

The device server does not send LCP echo requests.

lcp_ka_quiet_time=10-86400 seconds

Specifies the “quiet” interval, in seconds, after which the device server sends an LCP echo request. “Quiet” means not having received any bytes over the PPP link for the interval specified by this option.

lcp_ka_max_missed_replies={2-255|0=ignore missed replies}

Specifies how many consecutive echo replies may be missed before the device server disconnects the PPP link. A value of 0 (zero) specifies that the device server should not act on missed LCP echo replies by disconnecting the PPP link. Note that if bytes of any kind, LCP echo reply or otherwise, are received, the PPP link is deemed to be active, and the “missed LCP echo replies” count is reset to 0.

asyncmap=hex string

A mask for PPP connections that defines which of the 32 asynchronous control characters to transpose. These characters, in the range 0x00 to 0x1f, are used by some devices to implement software flow control. These devices may misinterpret PPP transmission of control characters and close the link. This mask tells PPP which characters to transpose.

The default is FFFF, which means transpose all 32 control characters. Any combination is valid. The following are the masks most likely used:

FFFFFFFF

Transpose all control characters.

00000000

Transpose none.

000A0000

Transpose Ctrl-Q and Ctrl-S.

chap_id=chap id

A character string that identifies the outbound PPP user using CHAP authentication. This is equivalent to a user or login name. The string must be 32 or fewer characters and must be recognized by the peer.

chap_key=chap key

A character string that authenticates the outbound PPP user using CHAP authentication. This is equivalent to a password. The string must be 16 or fewer characters and must be recognized by the peer.

pap_id=pap id

A character string that identifies the outbound PPP user using PAP authentication. This is equivalent to a user (or login) name. The string must be 32 or fewer characters and must be recognized by the peer.

pap_password=pap password

A character string that authenticates the outbound PPP user using PAP authentication. This is equivalent to a password. The string must be 16 or fewer characters and must be recognized by the peer.

mru=1500-2048

The maximum received unit (MRU), or frame size, in bytes, to be received from the other end of the PPP connection. This is a negotiated value. The default is 1500 bytes.

mtu=1500-2048

The maximum transmission unit (MTU), or frame size, in bytes, to use for this PPP outbound connection.

For PPP connections, the MTU is negotiated. Therefore, enter 1500, the largest size the Digi device will permit the remote host to send.

For PPP users, the range is 128 to 1500 bytes, and the default is 1500 bytes.

 

redial_attempts=attempts

 

The number of times the firmware will attempt to redial before giving up.

redial_delay=delay

The time to wait after an unsuccessful dial attempt.

rx_idle_timeout=timeout

The time, in seconds, after which if no data has been received over the link, the PPP connection is disconnected.

tx_idle_timeout=timeout

The time, in seconds, after which if no data has been transmitted over the link, the PPP connection is disconnected.

init_script=chat script

An initialization script, run once at interface startup. For example:

init_script=”'' ATZ OK \c”

dial_script=chat script

A dialing script, used any time a number is dialed for the interface. For example:

dial_script=”'' ATDT\T CONNECT \c”

login_script=chat script

A login script, used to log in to the remote system on the other end of the outbound PPP connection. For example:

login_script=”ogin: <username> assword: <password>”

n{1-4}=phone_number

Up to four phone numbers to dial to request a PPP outbound connection. The phone numbers are dialed sequentially.

proxy_arp={on|off}

When enabled, performs proxy ARP for the remote peer of the PPP session, so that the peer can be made to appear on our local network. It performs that proxy ARP on the subnet to which the IP address assigned to that peer belongs.

device_description=”description text”

An alternate string used for SNMP purposes. If this option value is set, it is used in the customized SNMP description for this interface. If not specified in the settings, the PPP device name (for example, ppp4) is used instead. This string allows for SNMP-produced information to fit better with network management software that prefers identification strings to be in a format such as mobile0.

See also