AR Router Maintenance Guide-FAQ(Interface Management)

This problem occurs because auto-negotiation is enabled on one interface but disabled on the other interface. Configure both interfaces to work in the same auto-negotiation mode. When auto-negotiation is enabled on one interface but disabled on the other interface, packet loss may occur even when both interfaces are in the Up state.

This problem may also occur when the network cable is loose.

The maximum transmission unit (MTU) of Layer 3 interfaces is configurable. The MTU of Layer 2 interfaces is not configurable.

By default, an Eth-Trunk interface is in hybrid mode, and is added to VLAN 1 in untagged mode. You can run undo port hybrid vlan 1 command in the interface view to delete the Eth-Trunk interface from VLAN 1.

The arp broadcast enable command is not executed on this subinterface.

To view traffic statistics on an interface, run the display interface [ interface-type [ interface-number [.subnumber ] ] ] command in any view, or run the display this interface command in the interface view.

To clear the traffic statistics on an interface, run the reset counters interface [ interface-type [ interface-number ] ] command in the user view.

The virtual port (VPORT) connects to an open virtual switch (OVS) in a virtualized environment and is named GigabitEthernet0/0/x. In the display interface brief command output, the GE interface with the largest interface number is the VPORT. The information "description VirtualPort" is displayed for the VPORT.

If the physical status of a 3G cellular interface (cellular interface) is Down, no 3G link is established and data service has not been transmitted yet. That is, no dialup is triggered or dialup fails on the 3G link.

NOTE:

If no dialup is triggered or dialup fails on a 3G link, the physical interface status is still Down even if a 3G data card (3G modem) is installed.

Configuring a static IP address for a 3G cellular interface may cause dialup to fail. In most cases, a network-side device dynamically allocates an IP address to a 3G cellular interface.

The USIM/SIM card on a 3G data card (3G modem) is not hot swappable.

The SIM card supports only the 2G services, while the USIM card supports both 2G and 3G services.

A 3G data card is hot swappable.

The possible causes are as follows:

• The 3G data card cannot be identified on the current network or is not supported on the AR.
• The 3G data card does not match the current network. For example, authentication or service required on the current network is not enabled on the data card or USIM/SIM card. As a result, authentication or negotiation fails in dialup.
• The 3G data card is not registered with available networks, due to weak signal strength or other reasons. Run the display cellular command to check information about 3G signals. The Current Service Status field must be displayed as "Service available", and the signal strength must be in the allowed range.
• An incorrect connection mode is configured on the 3G data card. For example, the 3G data card has a SIM card installed but its connection mode is set to WCDMA-only.
• The USIM/SIM card is not properly installed.
• The 2G/3G services are not enabled on the USIM/SIM card.
• The account balance of the USIM/SIM card is insufficient.
• The USIM/SIM card works incorrectly. Run the display cellular command to check whether the USIM/SIM card is in correct state. The status of the USIM/SIM card must be Ok not Not insert.
• Check whether 3G configurations, including the dialer number are correct. Check whether PPP authentication is required when the 3G cellular interface accesses a CDMA2000 network.
• No profile is configured or a profile is incorrectly configured.
• The 3G cellular interface is shut down using the shutdown command.

For a WCDMA data card:

• If the indicator blinks green twice at short intervals, the data card has not registered with the network.
• If the indicator blinks blue once every 2s (0.5 Hz), the data card has registered with the network.
• If the indicator is steady blue, dialup succeeds but the data card is not transmitting data services.
• If the indicator is steady light blue, dialup succeeds and the data card is transmitting data services.

For a CDMA2000 data card:

• If the indicator blinks blue once every 2s (0.5 Hz), the data card has not registered with the network.
• If the indicator blinks blue twice at short intervals, the data card has registered with the network.
• If the indicator blinks blue once every 0.25s (4 Hz), dialup succeeds and the data card is transmitting data services.

Run the display cellular command to view the Current RSSI field. If the Current RSSI field displays a value smaller than -85 dBm, the signal strength is weak and the data service rate is low and unstable. If the Current RSSI field displays a value smaller than -100 dBm, data cards may fail to register with or dial in to the network.

Each Layer 3 Ethernet interface has a MAC address.

A VLANIF interface obtains the device MAC address as its own MAC address. This MAC address is fixed.

A Bridge-if interface obtains the device MAC address as its own MAC address. This MAC address can be changed using the CLI.

The MAC address of a Layer 2 interface has no function on the device.

NOTE:

• To change the device MAC address, run the set system-mac { current | default } command in the diagnosis view, save the configuration, and restart the device.

• The system MAC address to be modified cannot be a multicast MAC address.

Currently, the fractional channelized board refers to the 1E1T1-F/2E1T1-F/4E1T1-F/8E1T1-F board.

The 1E1T1-F/2E1T1-F/4E1T1-F/8E1T1-F board line contains 32 timeslots that are numbered from 0 to 31. In fractional channelized mode, timeslot 0 is used to transmit synchronous information, and other timeslots can be bundled into a channel set.

V200R007 and later versions: For details about how to connect VDSL interfaces of the AR129, AR169, AR169EW, AR169CVW, AR169EGW-L, AR169CVW-4B4S, AR169G-L, AR169-P-M9, routers to other Huawei devices, see the AR Series Router VDSL Interconnection List. You can log in to Huawei enterprise support website (http://support.huawei.com/enterprise) to obtain the list based the product model and version.

Table 2-37 lists G.SHDSL board connection problems and solutions.

hnbdp_timeout

Yes, the combo interface on the SRU can connect to the 100M optical module. When the combo interface on the SRU connects to the 100M optical module, it does not support auto-negotiation mode, so the peer device must use the 100M optical module and the peer interface must be manually configured to work in full duplex mode.

When an SA card connects to an E1 card through a protocol converter such as CHANNEL-BANK, the protocol converter and E1 interface must be configured to work in unchannelized mode before the protocol status becomes up.

The E1-F card can communicate with the E1-M card in the following scenarios:

• The E1-M card works in E1 mode and the E1-F card works in unframed mode.
• The E1-M card works in CE1 mode and the E1-F card works in framed mode. Only one channel set is created on the E1-M card and binds the same timeslots as the E1-F card.

To solve this problem, configure configure an NQA test instance to detect the 3G link status.

1. Run the interface cellular interface-number command to enter the 3G cellular interface view.
2. Run the modem auto-recovery track nqa admin-name test-name [ probe-cycle period ] command to configure the device to use an NQA test instance to detect the 3G link status.
3. Run the modem auto-recovery track action modem-reboot fail-times times command to set the maximum number of 3G link detection failures in an NQA test instance. When the number of consecutive 3G link detection failures in an NQA test instance reaches the maximum value, the device restarts the 3G data card.

In framed mode, an E1-F interface supports two frame formats: CRC4 and non-CRC4.

By default, E1-F interfaces on Huawei devices use the non-CRC4 frame format and E1-F interfaces on Cisco devices use the CRC4 frame format. If the local and remote interfaces use different frame formats, the interfaces alternate between Up and Down states after being connected. To solve this problem, run the fe1 frame-format { crc4 | no-crc4 } command on the E1/T1-F card to set the frame format of E1-F interfaces first to ensure that the local and remote interfaces use the same frame format.

If a service exception occurs on an E1-F link, the possible cause is that the local and remote interfaces are configured with different CRC modes. By default, AR routers use 16-bit CRC mode. Devices from many other vendors may use 32-bit CRC mode. As a result, the local and remote devices cannot communicate.

Run the crc { 16 | 32 | none } command to configure the local interface to work in the same CRC mode as the remote interface. In addition, ensure that both the local and remote devices are grounded using ground cables.

Ground points on AR routers have the same appearance. The ground point on the AR151 is taken as an example, as shown in Figure 2-5.

Figure 2-5  Ground point on the AR151