Which of the following belong to BGP-recognized community attribute values? (Multiple choice)

The differences between IGMP versions are: (Multiple Choice)

The hello time of the BGP neighbor PeerA in the Open is 90s, and the Hold time of the PeerB in the Open is 30s. The interval for sending the keepalive message after the PeerA and PeerB are successfully connected is:

The OSFF NBMA network requires that routers in the network must select DR and BDR; otherwise, they can't work.

Which route prefixes in the following options are deny when matching the following IP-Prefix when using routing policy for route filtering? (Multiple choice)