(single) Is the following description correct? Before the upgrade operation, you need to stop the automatic save function of the system by using the command to avoid the conflict between the upgrade operation and the automatic save operation, and the upgrade fails.

When MA5600T configuring multicast services, which of the following options must be configured, otherwise, multicast program may not be able to watch? (Multiple choice)

(single) A part of the field in the IP packet is used to describe the lifetime of the packet, that is, the TTL value. What is the maximum value?

(single) Monitoring of environmental quantity refers to monitoring of environmental factors that may cause equipment damage, failure, and the like. Which of the following is not an object of environmental monitoring?

(single) Is the following description correct? Ethernet technology is a widely used technology. It is divided into 10M, 100M, and 1000M according to different transmission rates. The common transmission medium for 10M and 100M Ethernet is twisted pair, but 1000M Ethernet is too fast. The transmission medium must be optical fiber.