R3166-R3206-HP High-End Firewalls Network Management Configuration Guide-6PW101

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To do… Use the command… Remarks
Set the link change suppression
interval
timer hold seconds
Optional
10 seconds by default
NOTE:
You can increase the polling interval to reduce network instability due to time delay or heavy con
g
estion.
Configuring loopback testing on an Ethernet interface
If an Ethernet interface does not work normally, you can enable loopback testing on it to identify the
problem. Loopback testing has the following types:
• Internal loopback testing, which is performed within switching chips to test the functions related to
the Ethernet interfaces.
• External loopback testing, which is used to test the hardware functions of an Ethernet interface. To
perform external loopback testing on an Ethernet interface, you must install a loopback plug on the
Ethernet interface. In this case, packets sent from the interface are received by the same interface.
Follow these steps to enable loopback testing on an Ethernet interface:
To do… Use
the command… Remarks
Enter system view system-view —
Enter Ethernet interface view interface interface-type interface-number —
Enable loopback testing loopback { external | internal }
Optional
Disabled by default.
NOTE:
• On an interface that is physically down, you can only perform internal loopback testing. On an interface
administratively shut down, you can perform neither internal nor external loopback testing.
• The speed, duplex, mdi, and shutdown commands are not applicable during loopback testing.
• During loopback testing, an Ethernet interface works in full duplex mode. When you disable loopbac
k
testing, the duplex configuration of the interface restores.
Configuring a loopback interface
Introduction to loopback interfaces
A loopback interface is a software-only virtual interface. The physical layer state and link layer protocols
of a loopback interface are always up unless the loopback interface is manually shut down. A loopback
interface can be configured with an IP address. For the purpose of saving IP address resources, the IP
address is automatically configured with a 32-bit mask. Routing protocols can be enabled on a loopback
interface, and a loopback interface is capable of sending and receiving routing protocol packets.
Loopback interfaces are widely used. For example, you can configure a loopback interface address as
the source address of all the IP packets that the firewall generates. Because loopback interface addresses
are stable unicast addresses, they are usually used as device identifications. When you configure a rule
on an authentication or security server to permit or deny packets generated by the firewall, you can
streamline the rule by configuring it to permit or deny packets carrying the loopback interface address
identifying the firewall. When you assign an IP address to a loopback interface for source address
binding, make sure that the route from the loopback interface to the peer is reachable. As a result, all