Ethernet Port Configuration
153
Enabling Loopback
Detection on an
Ethernet Port
Loop occurs when a port receives the packets that it sent out. Loops may cause
broadcast storm. The purpose of loopback detection is to detect loops on a port.
With loopback detection enabled on an Ethernet port, the device checks the port
for external loopback periodically. Once a loopback is detected on the port, the
system does the following:
■
If loops are detected on a port that is of access type, the port will be shutdown.
Meanwhile, trap messages will be sent to the terminal, and the corresponding
MAC address forwarding entries will be removed.
■
If loops are detected on a port that is of trunk or hybrid type, trap messages are
sent to the terminal. If the loopback detection control function is also enabled
on the port, the port will be blocked, trap messages will be sent to the
terminal, and the corresponding MAC address forwarding entries will be
removed.
Follow these steps to configure loopback detection:
c
CAUTION:
■
Loopback detection on a given port is enabled only after the
loopback-detection enable
command has been issued in both system view
and the port view of the port.
■
Loopback detection on all ports will be disabled after the issuing of the
undo
loopback-detection enable
command in system view.
■
If the system detects loopback in multiple VLANs on a port in a detection
interval, it sends only one trap to the terminal rather than one trap per VLAN.
■
The aggregation port can not support loopback detection.
Configuring the Cable
Type for an Ethernet
Port
Two types of Ethernet cables can be used to connect Ethernet devices: crossover
cable and straight-through cable. To accommodate these two types of cables, an
To do…
Use the command…
Remarks
Enter system view
system-view
-
Enable global loopback
detection
loopback-detection enable
Required
Disabled by default
Configure the interval for port
loopback detection
loopback-detection
interval-time
time
Optional
30 seconds by default
Enter Ethernet port view
interface
interface-type
interface-number
-
Enable loopback detection on
the port
loopback-detection enable
Required
Disabled by default
Enable loopback detection
control on the port (Trunk or
Hybrid)
loopback-detection control
enable
Optional
Disabled by default
Enable loopback detection in
all the VLANs containing the
port
loopback-detection
per-vlan enable
Optional
Enabled only in the default
VLAN(s) with Trunk port or
Hybrid ports
Содержание 4800G Series
Страница 26: ...26 CHAPTER NETWORKING APPLICATIONS ...
Страница 30: ...30 CHAPTER 1 LOGGING IN TO AN ETHERNET SWITCH ...
Страница 62: ...62 CHAPTER 3 LOGGING IN THROUGH TELNET ...
Страница 70: ...70 CHAPTER 5 LOGGING IN THROUGH WEB BASED NETWORK MANAGEMENT SYSTEM ...
Страница 72: ...72 CHAPTER 6 LOGGING IN THROUGH NMS ...
Страница 82: ...82 CHAPTER 8 CONTROLLING LOGIN USERS ...
Страница 98: ...98 CHAPTER 9 VLAN CONFIGURATION ...
Страница 108: ...108 CHAPTER 10 VOICE VLAN CONFIGURATION ...
Страница 119: ...GVRP Configuration Examples 119 DeviceB display vlan dynamic No dynamic vlans exist ...
Страница 120: ...120 CHAPTER 11 GVRP CONFIGURATION ...
Страница 160: ...160 CHAPTER 17 PORT ISOLATION CONFIGURATION ...
Страница 172: ...172 CHAPTER 19 LINK AGGREGATION CONFIGURATION ...
Страница 196: ...196 CHAPTER 22 DLDP CONFIGURATION ...
Страница 240: ...240 CHAPTER 23 MSTP CONFIGURATION ...
Страница 272: ...272 CHAPTER 27 RIP CONFIGURATION ...
Страница 364: ...364 CHAPTER 29 IS IS CONFIGURATION ...
Страница 426: ...426 CHAPTER 31 ROUTING POLICY CONFIGURATION ...
Страница 442: ...442 CHAPTER 33 IPV6 RIPNG CONFIGURATION ...
Страница 466: ...466 CHAPTER 35 IPV6 IS IS CONFIGURATION ...
Страница 488: ...488 CHAPTER 36 IPV6 BGP CONFIGURATION ...
Страница 498: ...498 CHAPTER 37 ROUTING POLICY CONFIGURATION ...
Страница 540: ...540 CHAPTER 40 TUNNELING CONFIGURATION ...
Страница 552: ...552 CHAPTER 41 MULTICAST OVERVIEW ...
Страница 604: ...604 CHAPTER 43 MLD SNOOPING CONFIGURATION ...
Страница 628: ...628 CHAPTER 46 IGMP CONFIGURATION ...
Страница 699: ...Troubleshooting MSDP 699 4 Verify that the C BSR address is different from the anycast RP address ...
Страница 700: ...700 CHAPTER 48 MSDP CONFIGURATION ...
Страница 812: ...812 CHAPTER 57 DHCP SERVER CONFIGURATION ...
Страница 822: ...822 CHAPTER 58 DHCP RELAY AGENT CONFIGURATION ...
Страница 834: ...834 CHAPTER 61 BOOTP CLIENT CONFIGURATION ...
Страница 850: ...850 CHAPTER 63 IPV4 ACL CONFIGURATION ...
Страница 856: ...856 CHAPTER 64 IPV6 ACL CONFIGURATION ...
Страница 860: ...860 CHAPTER 65 QOS OVERVIEW ...
Страница 868: ...868 CHAPTER 66 TRAFFIC CLASSIFICATION TP AND LR CONFIGURATION ...
Страница 888: ...888 CHAPTER 69 PRIORITY MAPPING ...
Страница 894: ...894 CHAPTER 71 TRAFFIC MIRRORING CONFIGURATION ...
Страница 904: ...904 CHAPTER 72 PORT MIRRORING CONFIGURATION ...
Страница 930: ...930 CHAPTER 74 UDP HELPER CONFIGURATION ...
Страница 990: ...990 CHAPTER 79 FILE SYSTEM MANAGEMENT CONFIGURATION ...
Страница 1000: ...1000 CHAPTER 80 FTP CONFIGURATION ...
Страница 1020: ...1020 CHAPTER 82 INFORMATION CENTER CONFIGURATION ...
Страница 1038: ...1038 CHAPTER 84 SYSTEM MAINTAINING AND DEBUGGING ...
Страница 1046: ...1046 CHAPTER 85 DEVICE MANAGEMENT ...
Страница 1129: ...SSH Client Configuration Examples 1129 SwitchB ...
Страница 1130: ...1130 CHAPTER 88 SSH CONFIGURATION ...
Страница 1160: ...1160 CHAPTER 90 RRPP CONFIGURATION ...
Страница 1180: ...1180 CHAPTER 91 PORT SECURITY CONFIGURATION ...
Страница 1192: ...1192 CHAPTER 92 LLDP CONFIGURATION ...
Страница 1202: ...1202 CHAPTER 93 POE CONFIGURATION ...
Страница 1218: ...1218 CHAPTER 96 HTTPS CONFIGURATION ...