CNIT 344 Exam 2 Latest Update with Complete Solutions

CNIT 344 Exam 2 Latest Update with Complete Solutions IPv4 connectionless (the sender doesn't know if the receiver is present or if the packet arrived or if the receiver can read the packet), unreliable (IP does not have the capability to manage and recover from undelivered or corrupt packets, so other protocol layers manage reliability), media independent 32 bits/4 bytes Key piece of the IP Packet Header, length of IPv4 header Type of service Key piece of the IP Packet Header, 8 1-bit fields, QoS, DSCP Flag and Fragment Offset Key piece of the IP Packet Header, used in reconstruction of any fragments Time to Live Key piece of the IP Packet Header, maximum hops before undeliverable Protocol Key piece of the IP Packet Header, upper layer protocol (TCP/UDP) Source and destination address Key piece of the IP Packet Header, the two 32 bit binary values Network and host two parts of an IPv4 address Default gateway the address of the router interface, must be on the same network as all of the hosts Address resolution the process of mapping a hardware address to a higher-layer protocol address (maps IPv4 address to specific MAC address) CIDR Notation putting a slash after an IPv4 address that represents the number of network bits, also known as classless routing Layer 2 MAC addresses are at this layer Layer 3 Network address are at this layer NAT allows hosts in a private network to use a different IP address to access hosts and/or services on an external network, can be applied on source address or destination address Inside local address an RFC 1918 address assigned to a host on an inside network Inside global address a valid public address that the host on the inside network is assigned as it exits the router Outside global address a reachable IP address assigned to a host on the Internet True T/F: In NAT, 1 or more public IP addresses are assigned to a routing device and multiple internal clients use private IP addressing PAT used when there is more than one machine that is needing NAT, uses next available port gateway Port forwarding is typically done at the destination network's ? Reverse ARP broadcast a request for the IP address associated with a given MAC address, responds with an IP address, only assigns an IP address (not the default router and subnet mask) broadcast, unicast An ARP request is a ?; an ARP reply is a ? Address Resolution Protocol (ARP) method to send a packet/frame to another computer when the sending computer does not know the MAC address of the receiving computer, just the IP address of it, operates at datalink layer, Bootstrap Protocol (BootP) host can configure its IP parameters at boot time, not only assigns IP, but also assigns default router and network mask, operates at network layer 2 (MAC address) , 3 (IP address) To communicate, on an internetwork, a host needs logical knowledge of layer ? address and Layer ? address DHCP a framework for passing configuration information to hosts on a TCP/IP network, client server architecture Pack The lease time starts for DHCP when the DHCP sends the DHCP ? Automatic Private IP Addressing (APIPA) if a DHCP client is unable to locate a DHCP server and has no other configs, the computer configures itself with a 169.254.0.0/255.255.0.0 address; the computer then checks to make sure that address is not in use (through ARP request) and will attempt up to 10 different IP addresses DHCP Scope defines a set of IP addresses and associated configuration information that can be supplied to a DHCP client Available address pool remaining viable addresses DHCP is allowed to assign dynamically DHCP Reservation ensures that a device will always receive the same IP address when renewing its lease (static IPs), an IP address is set aside, or reserved, for a specific network device that has the Media Access Control (MAC) address associated with that IP address Internet Control Message Protocol (ICMP) offers messages to provide feedback about network operations and delivery of datagrams IP ICMP uses ? for the delivery of its messages False - it is required T/F: ICMP is not required in every IP deployment Type in the ICMP message format, defines the message format and options Code in the ICMP message format, defines additional operational actions of a specific message type Checksum a one's complement of one's complement sum of the ICMP message in 16-bit sections ICMP Type 0 echo reply ICMP Type 30 traceroute ICMP Type 3 destination unreachable Type 8 Code 0 (Echo Request) and Type 0 Code 0 (Echo Reply) the two ICMP message types that ping uses Traceroute used to determine the path a packet takes to a destination from a given source by returning the exact sequence of hops the test packet has traversed Type 30 Code 0 ICMP message type traceroute uses True T/F: ICMP is inherently insecure UDP connectionless, not reliable, provides minimal capabilities to deliver segments to a given destination TCP connection oriented, provides reliable host-to-host connection Control fields TCP header field, contains the flags (SYN, ACK, FIN, etc.) Sequence Number TCP header field, identifier of the segment being transferred Acknowledgement Number TCP header field, the value of the next sequence number expected to be received Data Offset TCP header field, the number of 32-bit words in the TCP header, indicates where the data begins Window TCP header field, the number of data bytes beginning with the one indicated in the ACK # field that this device is able to accept Checksum TCP header field, a 16-bit one's complement of the one's complement sum of segment Stream Control Transmission Protocol (SCTP) new protocol designed to offer reliable transmission over connectionless network Query message DNS message that consists of header and question records Response message DNS message that consists of header, question records, answer records, authoritative records, and additional records · Syn - initiator asks acceptor if it wants to set up a connection · Syn-Ack - the acceptor replies with an acknowledgement to the request · Ack - initiator acknowledges that the connecting has been established TCP 3-way handshake: File Transfer Protocol (FTP) standard mechanism provided by TCP/IP for copying a file from one host to another TFTP used when we need to simply copy a file without the need for all the features of FTP 7 Echo port 20 FTP port 23 Telnet port 25 SMTP port 53 DNS port 67 DHCP port (BootP) 69 TFTP port 80 HTTP port