HP VPN Firewall Appliances Network Management Configuration Guide
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To set the MTU for an Ethernet interface or subinterface:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter Ethernet interface
or subinterface view.
interface interface-type { interface-number |
interface-number.subnumber }
N/A
3. Set the MTU.
mtu size The default setting is 1500.
Configuring an Ethernet interface to operate in promiscuous mode
An Ethernet interface usually receives only packets with matched destination MAC addresses. After you
configure an Ethernet interface to operate in promiscuous mode, however, the interface no longer checks
the MAC addresses in received packets. Rather, it receives all Ethernet packets with correct format. You
might need to configure a network listening port to operate in promiscuous mode.
To configure an Ethernet interface to operate in promiscuous mode:
Ste
p
Command
Remarks
1. Enter system view.
system-view N/A
2. Enter Ethernet interface view.
interface interface-type
interface-number
N/A
3. Configure the Ethernet interface to
operate in promiscuous mode.
promiscuous
By default, an Ethernet interface does
not operate in promiscuous mode.
Configuring a loopback interface
Introduction
A loopback interface is a virtual interface. The physical layer state of a loopback interface are always up
unless the loopback interface is manually shut down. A loopback interface is widely used in the following
scenarios:
• A loopback interface address can be configured as the source address of the IP packets that the
device 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 that a device generates, you can simplify the rule by configuring
it to permit or deny packets carrying the loopback interface address that identifies the device.
When you use a loopback interface address as the source address of IP packets, make sure the
peer is reachable through routes by performing routing configuration. All data packets sent to the
loopback interface are considered as packets sent to the device itself, so the device does not
forward these packets.
• A loopback interface is often used in dynamic routing protocols. For example, if no router ID is
configured for a dynamic routing protocol, the highest loopback interface IP address is selected as
the router ID. In BGP, to avoid BGP sessions being interrupted by physical port failure, you can use
a loopback interface as the source interface of BGP packets.
Configuration procedure
To configure a loopback interface: