CNIT 34220 Exam 1 Questions and Answers CNIT 34220 Exam 1 Questions and Answers Already PassedAlready Passed

CNIT 34220 Exam 1 Questions and Answers Already Passed T/F: 192.168.1.IN-ADDR.ARPA is the typical name of the reverse address zone for the 192.168.1.0/24 network. False T/F: ICANN is responsible for creating top-level domains. True T/F: Best practice is to use your Internet DNS domain for your Active Directory. False T/F: The DNS system would take a disproportionate amount of the Internet bandwidth if it were not for caching. True T/F: From a practical perspective the DNS name space is larger than anyone should need. True T/F: To be considered authoritative, a DNS server must store records persistently. True T/F: You must provide three DNS servers that are available 24/7 to register a second level domain name. False PTR records should only be found in ________________ name resolution zones. reverse T/F: Root servers should only be consulted when a DNS server doesn't know the address of a DNS server that is authoritative for the domain in question. True T/F: PTR Records are used exclusively in forward name resolution tables. False T/F: DNS zones and domains are synonymous. False T/F: When using a relay host (forwarder), e-mail bounces can come from the origin host, the relay host, or the destination host. False T/F: When using a relay host you should limit the hosts that it will service. True T/F: E-mail is a real-time communication technique. False; store and forward T/F: IMAP is a means of retrieving mail on a server from a client. False; accessing T/F: SMTP is used to deliver mail between hosts. True Blacklisting services (MAPS, Spamhaus SBL, etc.) typically block specific e-mail from: addresses. False; content filtering T/F: SMTP session verification uses DNS to verify which servers should send mail for a domain. True T/F: A valid e-mail address contains a user name and a DNS entry. True T/F: SMTP only sends one copy of a message to a destination host regardless of how many users on the destination host are to receive the message. True T/F: A good spam control system should prevent user s from being able to over-ride spam decisions. False T/F: POP3 is a means of accessing mail on a server from a loosely attached (not on the network 24/7) client. False; retrieving T/F: SMTP natively supports eight-bit data encoding. False; seven How do you encode binary attachments for email transmission? MIME MIME Multi-purpose Internet Mail Extensions A spam control filtering technique that learns based on what the user thinks is spam is typically termed a ________________. Bayesian Filter T/F: The main reason for spam is an lack of authentication in SMTP. True main(s).top_level_domain - up to 127 levels of domains - 63 characters per name DNS Structure DNS Authority Hierarchy top level to lower levels T/F: InterNIC handles top level (root) domains. True mapping station names back to IP addresses Name Resolution - common to both DNS host names - on both server and users end hosts files - the traditional way- hard coded list of names and IP Addresses - assumes a station always has the same IP Address - works well with Manual or BOOTP, but not with DHCP Static DNS authoritative for a domain or sub-domain zone where multiple ISP's come together peering point - burden is on the Server to resolve the query - DNS client requires that the DNS server responds to the client with either the requested resource record or an error message - if server is not able to resolve the request, then it forwards the query to another DNS server until it gets an answer recursive name query - burden is on the client to resolve the query - DNS client allows the DNS server to return the best answer it can give based on its cache or zone data - client then queries the DNS server for which it obtained a referral and continues the process iterative name query - reduce the load on your authoritative server - must run duplicate services longer on DNS name changes - use this unless preparing to change addresses long TTL's states that this is the definitive name server for the domain SOA record types of DNS servers authoritative and non-authoritative contains the master list of name information primary authoritative server - acts as a backup to the primary server - copies the master list periodically (called zone transfer) secondary authoritative server types of non-authoritative servers caching and slave cannot recurse slave server - refers to primary and secondary servers for info as needed - can recurse caching server file on local DNS servers that contains the location of the root servers root hints file Zone transfers are done through port 53 because _____________. TCP is reliable - software solution that limits network connectivity based on packet characteristics - can control both ingress and egress traffic - determines whether the packet is allowed to be passed to an application packet filters Packet filters determine whether the packet is allowed to be passed to an application between layers ________ and ________ in the OSI model. 2; 3 - a router that contains a packet filter - dedicated software/hardware solution - should offer minimal (or no) other network service firewall - traditional approach -examines only the content of each packet individually - go/no go decisions are made on a per packet level - context of the packet is not considered (state of a TCP connection, preceding packets in a UDP connection) - available ports are shown as open FASTEST SOLUTION static packet filtering - the filter considers the context as well as the content of the packet (is the packet part of a known data flow) - automatically allows return flows - the standard for current packet filters dynamic packet filtering (SPI) three parts of a packet rule source, destination, action T/F: The rule to execute is determined by a first match algorithm. True TCP Port 25 SMTP TCP Port 80 HTTP UDP Port 53 DNS Allow/Permit Deny/Drop Reject actions - filter on device ingress, not egress - only filter for a match once - assign IP addresses to allow summarizable addresses to be used in rules packet filtering best practices deny exceptions to allow rules, allow rules, deny all general rule set structure Order rules so that the most common traffic is matched against the __________ rules. fewest - uses TCP for reliable connections - uses seven bit ASCII encoding SMTP Hosts will try to deliver mail for __________ hours before failing. 72 MTA will always look for _____________ first. an MX record The target of an MX record must be a(n) _______________ record. A - uses TCP for reliable connection - initiated by the client POP3 - similar to POP3 in functionality - used to access mail on a mail server IMAP - specialized mail servers - take a message sent to a single address and forward it to a list of addresses - can require significant bandwidth for SMTP traffic little administration required (user managed) list servers list server types unmoderated, self-moderated, moderated - communications is handled by NNTP - uses TCP for reliable communication Internet News T/F: Blacklisting causes significant collateral damage. True unsolicited email SPAM impact of SPAM on Internet community loss of bandwidth and routing resources impact of SPAM on companies and ISP's wasted internet bandwidth impact of SPAM on users potential loss of messages When was the first SPAM sent? 1994 - use open relays - fake return addresses - redirected return addresses - move server address around to avoid blacklists SPAM techniques filtering, blacklisting, session verification, message verification SPAM mitigation - only get rid of SPAM - be user manageable - minimize the performance impact of SPAM SPAM perfect solution - users form a network and report spam to a central server - once enough reports come in the content of the message is labeled spam - the updated detection rule is sent out to all clients cooperative filtering - client email application - relay host - incoming mail host content filtering locations - sending user has an account in the domain - sending server is authorized to send mail for the domain - adds some form of authentication to SMTP SMTP session verification implementations of SMTP session verification Sender ID (SID) Sender Policy Framework (SPF) message verification methods postage and PKI