多项选择题 A router with a serial interface will be used for an ISDN link.What other function group devices are required to complete the connection to the service provider? （）

单项选择题 A technician at TestKing needs to update the network documentation. One of the tasks includes documenting the name of the IOS image file of each router in the network.Which commands could be used to find this information?（）

多项选择题 Given a subnet mask of 255.255.255.224, which of the following addresses can be assigned to network hosts?（）