Which of the following protocols can be used to avoid loops in a redundant Layer 2 network?

Two static routes configured on the routers to reach network 10.1.1.1/32, which is not a static route set preference_value, the other a static route preference_value configured for 100, the following statements is correct ().

in the different exchange routing information between autonomous systems, routing policy and route filtering controls inter-domain routing information in the self-propagation, this routing protocol is ().

In the PPP, when the physical layer cannot detect the carrier or the management of the link to shut down operations, which link will be broken, then it is in what stage

D class IP address with the default subnet mask () bits