2026年更新的CCNA 200-301历年真题与练习测试，思科认证网络助理资格认证 | 思博网络

After mapping and multiplexing, 4 channels of ODU2 signals can be multiplexed into 1 channel of OTU3[ V ] signal, while for ODU2e signal, only 3 channels are needed to be multiplexed into 1 channel of OTU3 [V] signal.

The number of bit error blocks on each VC4 channel is detected by B3 on the receiving side. At the same time, the information is sent back to the sender via Q, and HP-REI and HP-FEBBE report on the sender.

Which of the following is the monitoring overhead for monitoring and reporting OTUk_DEG and OTUk_EXC alarms?

The levels of forced switching, fiber break switching, manual switching, and practice switching are arranged from high to low.

The optical amplifier unit compensates for line losses and extends the transmission distance. Connecting multiple optical amplifier units in cascaded mode allows for extended transmission distances without following the system.

K1 and K2 bytes can transmit APS switching signaling, and can also indicate that the signal of the multiplex section is invalid.

Compared with a dense wavelength division multiplexing (DWDM) system, a coarse wavelength division multiplexing (CWDM) system provides a certain number of wavelengths and a transmission distance within ( ) km, which greatly reduces system cost and has strong flexibility.

Compared with dense wavelength division multiplexing (DWDM) systems, crude glass division multiplexing (CWDM) systems provide a certain amount of glass length and transmission distance within (kmkm), which greatly reduces system cost and has strong flexibility

The clock unit can only access the external clock source as the timing signal source of the system through the external clock interface. In addition, it can also output the processed clock and provide the clock source for other devices that need timing.

The device IP addresses of the gateway network element and non-gateway network element must be set in the same network segment.

The number of network elements (including REG) in a two-fiber bidirectional multiplex section shared protection ring can exceed 16.

The standard Ethernet frame length should not be less than 64 bytes Which of the following factors contribute to this limitation? (Multiple choice).

If a bit error occurs in the SDH network, the service signal recovered after the signal is decapsulated must have a bit error.

When a bridge uses the IVL learning mode, the entry in the MAC address table is created according to the source MAC address and source port of the data frame. This entry is valid for all VLANs.

A. The value range of U-PTR is 0~782. When the receiving end receives invalid pointer values for 8 consecutive frames, which of the following alarms will the device generate?

QinQ technology is a technology of VLAN nesting. QinQ complies with IEEE 802.1q recommendations, and it is also a technology of VLAN extension.

When serious bit error seconds occur in the PM segment of ODUk, the network management will report the ODUk_PM_ES alarm.

A 1510 nm optical supervisory channel can be effectively amplified after it passes an EDFA.

When the bridge uses ivl learning mode, an entry in the MAC address table is created based on the source MAC address and source port of the teach frame. This entry applies to all VLANs

Which of the following statements about the MST functional module are correct? (Multiple Choice)

In the frame structure of SDH signals, there are abundant overhead bytes used for operation, administration, and maintenance (OAM). The overhead bytes account for ( ) of all bits in the entire frame and greatly enhance the monitoring functions of the network.

What is the function of the overhead TCM in ODUk?

What are the following steps for low-speed services to be multiplexed into high-speed SDH services? (Multiple choice)

When setting the LCAS mode, follow the following principles: 1. If devices at the two ends are both Huawei devices, set them to the "Standard Mode". 2. If a Huawei device is interconnected with a third-party device, set the interconnected devices to the same mode according to the mode supported by the third-party device.

When a working PQ1 board is faulty, the device performs TPS protection switching. Which of the following statements about the switching process are correct? (Multiple Choice)

Which of the following IP addresses is a Class C IP address?

Which of the following alarms is not a switching condition for a two-fiber bidirectional multiplex section protection ring?

Which of the following are the service board types of MSTP devices? (Multiple Choice)

The standard Ethernet frame length should not be less than 64 bytes. Which of the following factors cause this limitation? (Multiple Choice)

Which of the following is the database used by U2000 on PC/WIN2003?