Router interface configuration and management--2

Configuration and management of logical interfaces

The main example of this is the switch

First, Ethernet sub-interface configuration and management

The Ethernet sub-interface can be used for three-layer interoperability between VLANs and interconnection between LAN and WAN. In the three-tier interoperability, VLANs can logically divide a physical LAN into multiple broadcast domains, and hosts within the VLAN can communicate directly to each other at two levels, while hosts between VLANs cannot communicate with each other two layers. Three-tier technology is required to enable interoperability between different VLANs.

There are two ways to achieve this in Huawei devices:

1) on the three-layer switch through the Vlanif interface implementation;

2) on the router through the three layer Ethernet interface, which is commonly referred to as one-arm routing.

The traditional three-layer Ethernet interface does not support VLAN packets and is discarded when VLAN packets are received as illegal messages. In order to achieve inter-VLAN interoperability, the Ethernet sub-interface can be created on the three-layer Ethernet interface, and the VLAN tags in VLAN packets are stripped off by deploying the terminating sub-interface function on the sub-interface, thus enabling three-layer interoperability between VLANs.

In the area of LAN and wide area network, most of the messages in LAN have VLAN tags, but some WAN protocols do not recognize VLAN packets, such as ATM, FR, PPP, etc., if you need to forward VLAN packets in the LAN to the WAN, you need to create a sub-interface on the out interface. VLAN messages are the VLAN information that first logs the messages locally, then the VLAN tags are stripped off and then forwarded.

Users belonging to different VLANs and at different network segments can implement VLAN communication over a three-tier network by deploying sub-interfaces, configuring IP addresses, and associated with VLANs.

s use the following command to view the relevant configuration on the Ethernet subinterface:

1) Display Interface "Interface-type" Interface-number ". Subnumber "": View the status of the specified or all Ethernet sub-interfaces.

2) Display dot1q information termination "interface Interface-type Interface-number". Subnumber "": View the names of all interfaces configured with the DOT1Q endpoint and the number of rules that the terminating subinterface has for the end of the user message.

3) Display QINQ information termination "interface Interface-type Interface-number". Subnumber "": View the names of all interfaces configured with the QINQ endpoint and the number of rules that the terminating subinterface has for the end of the user message.

Second, loopback interface configuration and management

The loopback is a three-layer logical interface, and multiple loopback interfaces can be created on a single switch. once the loopback interface is created, the interface remains up (but can be deleted), so the user can configure the loopback interface to improve network reliability. And the loopback interface can be configured with a 32-bit mask IP address. The loopback interface typically has the following main applications:

1), the IP address of the loopback interface is designated as the source address of the message, which can improve the network reliability.

2), in some dynamic routing protocols, when the router ID is not configured, the maximum number of IP addresses on all loopback interfaces will be selected as router IDs.

3), in the BGP protocol, the source interface that sends the BGP message is configured as the loopback interface to ensure that the BGP session is not affected by the physical interface failure.

4), the loopback interface can be configured with a mask of 1 IP addresses, thereby saving the IP address.

5), loopback interface can be configured IPV4 address, can be used to bind VPN instance, to verify the source IPv4 address.

The loopback interface can only configure IP addresses and source IP address checks for messages.

You can use display interface loopback "Loopback-number" to view the status information for all or the specified loopback interface.

Third, configure the Null interface

The null interface is created automatically by the system and has only a null interface numbered 0, remains up, cannot be configured like an IP address or other protocol, cannot be used to forward messages, and any network data packets sent to that interface will be discarded. If the next hop that reaches a segment is specified in a static route as the NULL0 interface, any data packets sent to that segment will be discarded.

Router WAN Interface Configuration

First, serial interface configuration and management

The serial interface is one of the most commonly used WAN interfaces and works in both synchronous and asynchronous ways, so it is often referred to as the same/asynchronous serial port. In the AR G3 series routers, the serial interface is comprised of a 1SA (1 port sa)/2SA (2 port SA) interface card.

Support the configuration of the serial interface router model lookup manuals, these support serial interface devices, the supported synchronous serial port is configured to work in synchronous mode of the same/asynchronous serial port, the interface name is serial; the supported asynchronous serial ports are two types:

--the same/asynchronous serial port is configured to work asynchronously, and the interface name is serial.

--dedicated asynchronous serial port with an interface name of async.

1. Serial interface works in synchronous mode

The default mode of operation for the serial interface is synchronous. When the serial interface is connected as a DDN leased line, or the serial interface works in synchronous mode, the serial interface has the following characteristics in the synchronous mode:

1) The serial interface can work in the DTE (data Terminal equipment, terminal equipment) and DCE (data circuit-termination equipment, terminal equipment) two ways.

In the serial interface The DTE cable (one end of the pin connector, commonly known as the "male") device is called the DTE device, such as a client-side router device, and a DCE cable is inserted in the serial interface (one end of a hole connector, commonly known as a "female") device called a DCE device, such as a variety of server hosts, or carrier's router device. In general, the router device acts as a DTE device, accepting the clock provided by the DCE device.

In the user's private network, you can optionally specify any one end of the serial link as a DTE or DCE as needed, and one end of the DCE is used to specify the clock, and one end of theDTE is used to synchronize with the DCE clock, which specifies the baud rate to be configured as one end of the DCE device. And the same virtual baud rate as the DCE-end baud rate is configured at one end of the DTE device . Supports multiple physical layer protocols: v.24/v.35/x.21 and other protocols, but currently does not support x.21 DCE. The maximum rate for the v.24 is 64kbit/s,v.35, which is 2.048mbit/s.

2) The Protocol types supported by the link layer include PPP, Frame Relay (FR), and HDLC.

3) Support IP Network layer protocol, that is, the IP address can be configured.

The serial interface in synchronous mode is mainly used to realize the interconnection between the Enterprise branch office and the headquarters through the PPP link.

2. Serial interface works in asynchronous mode

When connecting the serial interface as an asynchronous leased line, or using the serial interface for modem dialing, data backup, and access termination, it works asynchronously. In asynchronous mode, the serial interface can work in protocol mode or in stream mode.

1) Protocol mode means that after the physical connection of the serial interface is established, the interface directly adopts the existing link layer protocol configuration parameters, then establishes the link. In protocol mode, the link layer protocol type is PPP and supports IP Network layer protocol.

2) Flow mode refers to the serial interface on both ends of the device into the interaction phase, the device at the end of the link can send configuration information to the peer device, set the physical layer parameters of the peer device, and then establish the link. In streaming mode, the link layer protocol and IP Network layer protocol configuration are not supported.

3. Configure the physical and link properties of the serial interface under synchronous mode

The serial interface also has DTE and DCE two modes of operation in synchronous mode. In general, the synchronous serial port is usually used as the DTE device, accepting the clock provided by the DCE device.

1) Configure the physical properties of the serial interface to work in the DTE or DCE mode

The physical properties of the serial interface (DTE or DCE) in synchronous mode have default values, so they are generally not configured or can be modified by the following table configuration method.

2), configure the link Layer Properties of the serial interface under synchronous mode

By default, the link-layer properties of the serial interface (DTE or DCE) in synchronous mode have default values, generally no configuration, or you can modify the property configuration by following the table.

4. Configuring the Serial Interface physical and link properties in asynchronous mode

When the serial interface is used asynchronously to host the upper-layer data service, it is necessary to configure the mode of operation and related properties of the serial interface under asynchronous mode so that the serial interface physical layer and the link layer state are up asynchronously.

1) Configuring the Serial Interface physical properties in asynchronous mode

When users need to log on to devices via an asynchronous serial port, they need to have SA (the same/asynchronous WAN interface) or as (Asynchronous WAN Interface Board) on the device. If it is on the SA board, the interface mode on the SA board needs to be set to asynchronous mode, and the physical properties of the HyperTerminal and the physical properties of the device are consistent when the user logs on to the device via an asynchronous serial port.

Asynchronously, the serial interface uses a TTY (True type Terminal, entity type Terminal) user interface, and the physical properties are configured as follows:

Here the configuration can be seen, with the console port of the user interface physical property settings are very similar to the HyperTerminal settings compared to know what the meaning of (see the previous console configuration).

2SA Single Board configuration and the interface and user interface in the system: note the slot number, from top right to bottom left, starting with 1 increments. This is inserted in slot number 1th.

2) Configure the link Properties of the serial interface under asynchronous mode

By default, the link properties of the serial interface have default values in asynchronous mode.

The flow mode in asynchronous mode (Async mode flow) is equivalent to a direct cable connection that connects each line in the cable directly to the asynchronous port pins on both ends, so the link layer protocol and the IP Network layer protocol are not supported.

5. Serial Interface Management

1) Display interface serial "Interface-number": View basic configuration information and statistics for the serial interface

2) Display interface brief serial "Interface-number": View the physical status of the serial interface, link protocol status, bandwidth utilization, and error messages, and other brief information. (This command cannot be performed under ENSP, use display interface Brief | Include Serial)

3) Display IP interface brief serial "Interface-number": View information such as physical status and IP address.

6. Configuration example of serial interface connection network under synchronous mode

Routers AR2 and AR3 are connected via the serial interface, the AR2 side interface is the DTE interface, and the AR3 side interface is the DCE interface.

Configuration ideas:

1) Configure the physical properties of the serial interface under synchronous mode so that the physical layer status of the interface is up.

2) Configure the link layer attribute of the serial interface under synchronous mode so that the link layer protocol status of the interface is up.

3) Configure the IP address of the serial interface under synchronous mode to make the interface connected to the IP network interoperable.

Specific configuration steps:

[R2]interface serial 1/0/0
[R2-serial1/0/0]clock RC #---Configuring the serial interface on the DTE device using receive clock mode
[R2-serial1/0/0]virtualbaudrate 72000 #--Configure the serial interface on the DTE device with a virtual baud rate of 72000bit/s
[R2-serial1/0/0]link-protocol PPP
[R2-SERIAL1/0/0]MTU 1400
[R2-serial1/0/0]shutdown
[R2-serial1/0/0]undo shutdown
[R2-serial1/0/0]ip Address 10.1.1.1 30
[R2-serial1/0/0]quit

[R3]interface serial 2/0/0
[R3-serial2/0/0]baudrate 72000 #--Configure the serial interface on the DCE device with a baud rate of 72000bit/s, the same as the virtual baud rate on R2
[R3-serial2/0/0]link-protocol PPP
[R3-SERIAL2/0/0]MTU 1400
[R3-serial2/0/0]shutdown
[R3-serial2/0/0]undo shutdown
[R3-serial2/0/0]ip Address 10.1.1.2 30
[R3-serial2/0/0]quit

In the experiment on ENSP, the two routers are AR1220, when the baud rate is configured, there is no baudrate command on the interface, and when the display interface serial 2/0/0 is used

The display interface is DTE, look at R2: the virtual baud rate of both is also different

+

The two can still be interconnected.

Router interface configuration and management--2