72
C
HAPTER
14: B
ASIC
P
ORT
C
ONFIGURATION
Setting Loopback
Detection for an
Ethernet Port
Loopback detection is used to monitor if loopback occurs on a switch port.
After you enable loopback detection on Ethernet ports, the switch can monitor if
external loopback occurs on them. If there is a loopback port found, the switch will
put it under control.
■
If loopback is found on an access port, the system disables the port, sends a Trap
message to the client and removes the corresponding MAC forwarding entry.
■
If loopback is found on a trunk or hybrid port, the system sends a Trap message to
the client. When the loopback port control function is enabled on these ports, the
system disables the port, sends a Trap message to the client and removes the
corresponding MAC forwarding entry.
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.
The commands of loopback detection feature cannot be configured with the
commands of port link aggregation at the same time.
Configuring the
Ethernet Port to Run
Loopback Test
You can configure the Ethernet port to run loopback test to check if it operates
normally. The port running loopback test cannot forward data packets normally. The
loopback test terminates automatically after a specific period.
Table 54
Set loopback detection for an Ethernet port
Operation
Command
Remarks
Enter system view
system-view
—
Enable loopback detection
globally
loopback-detection enable
Optional
By default, loopback detection is
disabled globally.
Set time interval for port
loopback detection
loopback-detection
interval-time
time
Optional
The default interval is 30 seconds.
Enter Ethernet port view
interface
interface-type
interface-number
—
Enable loopback detection
on a specified port
loopback-detection enable
Optional
By default, port loopback
detection is disabled.
Enable loopback port
control on the trunk or
hybrid port
loopback-detection control
enable
Optional
By default, loopback port control
is not enabled.
Configure the system to
run loopback detection on
all VLANs for the trunk and
hybrid ports
loopback-detection per-vlan
enable
Optional
By default, the system runs
loopback detection only on the
default VLAN for the trunk and
hybrid ports.
Display port loopback
detection information
display loopback-detection
Optional
You can use the command in any
view.
Table 55
Configure the Ethernet port to run loopback test
Operation
Command
Remarks
Enter system view
system-view
—
Enter Ethernet port view
interface
interface-type interface-number
—
Summary of Contents for 4200G 12-Port
Page 10: ...8 CONTENTS...
Page 14: ...4 ABOUT THIS GUIDE...
Page 46: ...32 CHAPTER 5 LOGGING IN THROUGH WEB BASED NETWORK MANAGEMENT SYSTEM...
Page 48: ...34 CHAPTER 6 LOGGING IN THROUGH NMS...
Page 60: ...46 CHAPTER 9 VLAN CONFIGURATION...
Page 64: ...50 CHAPTER 10 MANAGEMENT VLAN CONFIGURATION...
Page 80: ...66 CHAPTER 13 GVRP CONFIGURATION...
Page 98: ...84 CHAPTER 15 LINK AGGREGATION CONFIGURATION...
Page 112: ...98 CHAPTER 18 MAC ADDRESS TABLE MANAGEMENT...
Page 126: ...112 CHAPTER 19 LOGGING IN THROUGH TELNET...
Page 162: ...148 CHAPTER 20 MSTP CONFIGURATION...
Page 274: ...260 CHAPTER 29 IGMP SNOOPING CONFIGURATION...
Page 276: ...262 CHAPTER 30 ROUTING PORT JOIN TO MULTICAST GROUP CONFIGURATION...
Page 298: ...284 CHAPTER 33 SNMP CONFIGURATION...
Page 304: ...290 CHAPTER 34 RMON CONFIGURATION...
Page 338: ...324 CHAPTER 36 SSH TERMINAL SERVICES...
Page 356: ...342 CHAPTER 38 FTP AND TFTP CONFIGURATION...
Page 365: ...Information Center Configuration Example 351 S4200G terminal logging...
Page 366: ...352 CHAPTER 39 INFORMATION CENTER...
Page 378: ...364 CHAPTER 40 BOOTROM AND HOST SOFTWARE LOADING...
Page 384: ...370 CHAPTER 41 Basic System Configuration and Debugging...
Page 388: ...374 CHAPTER 43 NETWORK CONNECTIVITY TEST...
Page 406: ...392 CHAPTER 45 CONFIGURATION OF NEWLY ADDED CLUSTER FUNCTIONS...