CCNA Questions

A CIDR address of/19 is 255.255.224.0. This is a Class B address, so that is only 3 subnet bits, but it provides 13 host bits, or 8 subnets, each with 8,190 hosts.

Class C network address has only 8 bits for defining hosts : 28-2 = 256 - 2 = 254

If a switch has three computersconnected to it, with no VLANs present , one broadcast and three collision domains are created.

Flow control allows the receiving device to control  the transmitter so the receiving device's buffer does not overflow.

A/23 is 255.255.254.0. The third octet is a block size of 2.0, 2, 4. The subnet is in the 16.2.0 subnet; the broadcast address is 16.3.255

If a DHCP Conflict is detected, either by the server sending a ping and getting response or by a host using a gratuitous ARP (arp'ing for its own IP address and seeing if a host responds), then the server will hold that address and not use it again until it is fixed by an administrator.

when trying to find the best answer to an access - list question, always check the access - list bnumber and then the protocol. When filtering to an upper - layer protocol, you must use an extended list, numbers 100 - 199 and 2000 - 2699. Also, when you filter to the port of an upper - layer protocol, you must use either tcp or udp in the ACL protocol field. If it says ip in the protocol field, you cannot filoter on the port number of an upper - layer protocol. SMTP uses TCP

Routers operate at layer 3. LAN switches operate at layer 2. Ethernet hubs operate at layer 1. Word processing applications communicate to the Application layer interface, but do not operate at layer 7, so the answer would be none.