User manual 3COM H3C S3100 16C SI

[. . . ] 2-5 2. 1. 5 loopback-detection per-vlan enable . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-5 2. 1. 6 loopback-detection shutdown enable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-6 i H3C Loopback Detection Feature Manual Release 2107 Chapter 1 Loopback Detection Configuration Chapter 1 Loopback Detection Configuration Note: Two functions are added to release 2107: configuring loopback detection for a list of ports in bulk, and enabling auto-shutdown of loopback ports. 1. 1 Loopback Detection Configuration 1. 1. 1 Loopback Detection Overview Loopback detection is used to monitor if a port of a switch is looped back. After you enable loopback detection on Ethernet ports, the switch can monitor if an external loopback occurs on them. [. . . ] These switches are all shipped with a default configuration file (config. def). -- Remarks Enable loopback detection globally loopback-detection enable Enable loopback detection on the specified ports in bulk loopback-detection interface-list enable Set the interval for performing port loopback detection Enter Ethernet port view loopback-detection interval-time time interface interface-type interface-number 1-2 H3C Loopback Detection Feature Manual Release 2107 Chapter 1 Loopback Detection Configuration Operation Command Optional Remarks Enable loopback detection on a specified port loopback-detection enable By default, the loopback detection function is enabled on ports if the device boots with the default configuration file (config. def); if the device boots with null configuration, this function is disabled. Optional Enable loopback port control on the trunk or hybrid port loopback-detection control enable By default, the loopback port control function is enabled on ports if the device boots with the default configuration file (config. def); if the device boots with null configuration, this function is disabled. Optional By default, the loopback port auto-shutdown function is enabled on ports if the device boots with the default configuration file (config. def); if the device boots with null configuration, this function is disabled. Optional Enable the loopback port auto-shutdown function loopback-detection shutdown enable Configure the system to run loopback detection on all VLANs of the current trunk or hybrid port loopback-detection per-vlan enable By default, the system runs loopback detection only on the default VLAN of the current trunk or hybrid port. Caution: To enable loopback detection on a specific port, you must use the loopback-detection enable command in both system view and the specific port view. After you use the undo loopback-detection enable command in system view, loopback detection will be disabled on all ports. 1-3 H3C Loopback Detection Feature Manual Release 2107 Chapter 2 Loopback Detection Configuration Commands Chapter 2 Loopback Detection Configuration Commands Note: Two functions are added to release 2107: configuring loopback detection for a list of ports in bulk, and enabling auto-shutdown of loopback ports. For detailed description of the two functions, refer to loopback-detection interface-list enable and loopback-detection shutdown enable. 2. 1 Loopback Detection Configuration Commands 2. 1. 1 loopback-detection control enable Syntax loopback-detection control enable undo loopback-detection control enable View Ethernet port view Parameter None Description Use the loopback-detection control enable command to enable the loopback port control function on the current trunk or hybrid port. Use the undo loopback-detection control enable command to disable the loopback port control function on the trunk or hybrid port. The loopback port control function works in conjunction with the loopback detection function (refer to loopback-detection enable). If a loop is found on a VLAN of the trunk or hybrid port: With the function enabled on the trunk or hybrid port, the system will set the port to the block state (ports in this state cannot forward data packets), send log messages to the terminal, and remove the corresponding MAC forwarding entry. 2-1 H3C Loopback Detection Feature Manual Release 2107 Chapter 2 Loopback Detection Configuration Commands After the loop is removed, the port will automatically resume the normal forwarding state. With the function disabled on the trunk or hybrid port, the system will only send log messages to the terminal, and the port is still in the normal forwarding state. By default, the loopback port control function is enabled on ports if the device boots with the default configuration file (config. def); if the device boots with null configuration, this function is disabled. Note that this command is invalid for an access port. Related command: loopback-detection enable. Example # Enable the loopback port control function on Ethernet 1/0/1. <H3C> system-view System View: return to User View with Ctrl+Z. [H3C] interface ethernet 1/0/1 [H3C-Ethernet1/0/1] port link-type trunk [H3C-Ethernet1/0/1] loopback-detection control enable 2. 1. 2 loopback-detection enable Syntax loopback-detection enable undo loopback-detection enable View System view or Ethernet port view Parameter None Description Use the loopback-detection enable command to enable the loopback detection function on the current port to detect whether an external loopback occurs on the port. Use the undo loopback-detection enable command to disable the loopback detection function on the port. 1) If a loop is found on an access port, the system will set the port to the block state (ports in this state cannot forward data packets), send log messages to the terminal, and remove the corresponding MAC forwarding entry. If you have enabled the loopback port auto-shutdown function (with the loopback-detection shutdown enable command) on the access port, the system 2-2 H3C Loopback Detection Feature Manual Release 2107 Chapter 2 Loopback Detection Configuration Commands will shut down the port, and send log messages to the terminal. After the loop is removed, you need to use the undo shutdown command to bring up the port. If you have not enabled the loopback port auto-shutdown function on the access port, the port will automatically resume the normal forwarding state after the loop is removed. [. . . ] Note that the command is invalid for any access port. Example # Configure the system to run loopback detection on all VLANs of the trunk port Ethernet1/0/1. <H3C> system-view System View: return to User View with Ctrl+Z. [H3C] interface ethernet 1/0/1 [H3C-Ethernet1/0/1] port link-type trunk [H3C-Ethernet1/0/1] loopback-detection per-vlan enable 2. 1. 6 loopback-detection shutdown enable Syntax loopback-detection shutdown enable undo loopback-detection shutdown enable View Ethernet port view Parameter None Description Use the loopback-detection shutdown enable command to enable the loopback port auto-shutdown function. Use the undo loopback-detection shutdown enable command to disable the function. The loopback port auto-shutdown function works in conjunction with the loopback detection function (refer to loopback-detection enable). [. . . ]