$ Linux Command

Network

ppp-off

Disconnect a PPP connection.

pppdialupmodemconnectiondisconnect

Additional Notes

ppp-off is a script (typically a shell script) that terminates an active PPP (Point-to-Point Protocol) connection. It sends the appropriate signals to the PPP daemon (pppd) to disconnect the link, hang up the modem, and clean up network interfaces and routing table entries.

PPP is a data link protocol used to establish direct connections between two networking nodes. While largely replaced by broadband and mobile technologies, PPP is still used in DSL connections (PPPoE), dial-up access, serial console connections, and certain embedded systems. The ppp-off script is part of the ppp package on Linux systems.

Syntax

ppp-off [device]

Parameters

  • device: The TTY device used by the PPP connection (e.g., ttyS0, ttyUSB0). If omitted, the default device is used.

Examples

ppp-off

Disconnect the current PPP connection.

ppp-off ttyS0

Disconnect the PPP connection on serial port ttyS0.

ppp-off ttyUSB0

Disconnect a PPP connection on a USB modem.

Practical Notes

  • ppp-off is a script, not a binary. Its location varies: /etc/ppp/ppp-off, /usr/sbin/ppp-off, or /usr/bin/ppp-off.
  • For PPPoE connections used in DSL, use poff (from rp-pppoe) instead.
  • On modern systems, the pppd daemon can be managed with killall pppd or systemctl stop pppd as alternatives.
  • Before running ppp-off, ensure the PPP interface is active. Check with ifconfig ppp0 or ip addr show ppp0.
  • The pon script starts a PPP connection; ppp-off terminates it.