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34
L
OOPBACK
D
ETECTION
C
OMMANDS
The switch can be configured to detect general loopback conditions caused
by hardware problems or faulty protocol settings. When enabled, a control
frame is transmitted on the participating ports, and the switch monitors
inbound traffic to see if the frame is looped back.
U
SAGE
G
UIDELINES
The default settings for the control frame transmit interval and recover
time may be adjusted to improve performance for your specific
environment. The shutdown mode may also need to be changed once
you determine what kind of packets are being looped back.
General loopback detection provided by the command described in this
section and loopback detection provided by the spanning tree protocol
cannot both be enabled at the same time. If loopback detection is
enabled for the spanning tree protocol, general loopback detection
cannot be enabled on the same interface.
When a loopback event is detected on an interface or when a interface
is released from a shutdown state caused by a loopback event, a trap
message is sent and the event recorded in the system log.
Loopback detection must be enabled both globally and on an interface
for loopback detection to take effect.
Table 103: Loopback Detection Commands
Command
Function
Mode
Enables loopback detection globally on the
switch or on a specified interface
GC, IC
Specifies shutdown by dropping packets for
ports detected in loopback state or by dropping
packets belonging to VLANs detected in
loopback state
GC
Specifies the interval to wait before releasing an
interface from shutdown state
GC
Specifies the interval at which to transmit
loopback detection control frames
GC
Manually releases all interfaces currently shut
down by the loopback detection feature
PE
Shows loopback detection configuration settings
for the switch or for a specified interface
PE
Summary of Contents for DG-FS4528P
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Page 148: ...CHAPTER 5 Simple Network Management Protocol Configuring SNMPv3 Groups 148 ...
Page 389: ...CHAPTER 17 VoIP Traffic Configuration Configuring Telephony OUI 389 ...
Page 515: ...CHAPTER 22 System Management Commands UPnP 515 TTL 20 Console ...
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