H3C Technologies H3C SecPath F1000-E - Manual (Page 26)

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Configuring interface management
Feature and hardware compatibility
Feature F1000-A-EI/E-SI/S-AI F1000-E F5000-A5 Firewall module
Subinterface rate statistics
collection on an Ethernet
interface
No Yes Yes Yes
Jumbo frame support No Yes No Yes
Overview
An interface is the point of interaction or communication between devices. It is used for exchanging data
between devices. A physical interface is an interface that materially exists and is supported by a device.
For example, an Ethernet interface is a physical interface. A logical interface is an interface that can
implement data switching but does not exist physically. A logical interface must be established through
configuration.
The interface management feature is used by the Web-based configuration interface to manage all
physical interfaces and the following types of logical interfaces of a device:
• Loopback interfaces—A software-only virtual interface. Once a loopback interface is created, its
physical status is always up and link layer protocols are enabled unless you manually shut down the
interface. You can enable routing protocols on a loopback interface, and enable it to receive and
transmit routing protocol packets. When you assign an IPv4 address for a loopback interface, the
subnet mask must be 32-bit long.
• Null interface—A software-only virtual interface. A null interface is always up and can neither
forward data packets nor be configured with an IP address or any link layer protocol. With a null
interface specified as the next hop of a static route to a specific network segment, any packets
routed to the network segment are dropped. The null interface provides a simpler way to filter
packets than access control list (ACL). You can filter uninteresting traffic by transmitting it to a null
interface instead of applying an ACL.
• Layer 2 Ethernet subinterface—Operates on the data link layer and processes Layer 2 protocols,
and is mainly used for inter-VLAN packet forwarding on firewall cards. The link type of a Layer 2
Ethernet subinterface is access, which cannot be changed. You can add a Layer 2 subinterface to
a VLAN. For more information, see "Configuring VLANs"
• Layer 3 Ethernet subinterface—Operates on the network layer and processes Layer 3 protocols.
You can assign an IP address to a Layer 3 Ethernet subinterface. Layer 3 Ethernet subinterfaces are
configured mainly to enable Layer 3 Ethernet interfaces to send and receive VLAN-tagged packets.
• VLAN interface—Virtual Layer 3 interface used for Layer 3 communications between VLANs. Each
VLAN interface corresponds to a VLAN. You can assign an IP address to a VLAN interface and
specify it as the gateway of the corresponding VLAN to forward traffic destined for an IP network
segment different from that of the VLAN.