Final Networking Exam
Terms
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- POP3 Reserved Port
- TCP 110 (listens)
- GAME: packet header signature?
- Signature (i.e. CSDT) (4bytes), Version (1byte), Sequence (1byte), Type (2bytes), Message (2bytes), Length (2bytes)
- network address
- 0s, found by performing a logical "AND" of a given address and netmask
- NAT
- Network Address Translation; router dynamically rewrites IP address so multiple computers can share same IP address
- SMTP
- Simple Mail Transfer Protocol, used to send mail
- HTTP Request Methods
- GET, HEAD, POST
- IDS
- Intrusion Detection Software/System; alert you to possible intrusions and suspicious traffic
- GAME: login sequence?
- C: send announce/want to login, S: challenge, C: response (password), S: result (success/fail, message)
- Compare and contrast LAN vs WAN
- LAN and WAN are both area networks of computers connected in a geographic area, LAN is smaller like in a building, WAN is larger like across a city
- Compare and contrast IDS and NIDS
- NIDS is just network component of IDS, IDS can be network-IDS, protocol-based IDS, application-protocol-based IDS, host IDS, or hybrid IDS
- Ethernet
- uses bus topology, most common hardware-level protocol/topology in use today, 1-physical layer, operates at 10mpbs, 100mbps, and 1gbps
- netmask
- specifies a "subnet" or valid IP address range for a LAN, does so by using a "bitmask" stencil/filter to force bits you don't care about to 0 or off
- UDP
- User Datagram Protocol, provides applications with connectionless communication service
- HTTP
- HyperText Transfer Protocol, used to send and receive information over Internet, uses clients and servers, request/response
- TCP/UDP Port
- a software port, a number for communications over a single IP address, used to identify specific applications data goes to
- hub
- simple/dumb electronic device connecting LAN network devices, sends packets to all devices regardless of intended recipient
- Important HTTP Headers
- Content-Type & Content-Length
- GAME: generic packet structure?
- struct Packet_Generic { Packet_Header Header; char buffer[1]; }
- Find network and broadcast addresses from IP: 134.50.241.7 and netmask: 255.255.0.0
- Network address: 134.50.0.0, Broadcast address: 134.50.255.255
- GAME: packet header structure?
- struct Packet_Header { (all are unsigned) int Signature; char Version; char Sequence; short Type; short Message; short Length;}
- SNMP
- Simple Network Management Protocol; play with printers; get info/stats/settings of network devices by manipulating MIBs (Management Information Bases)
- Firewall
- an intrusion defense measure
- Compare and contrast NAT/NAPT and a firewall
- NAT and NAPT are for multiple computers and dynamically rewrite packet info, while firewalls check packets against a rule set to decide whether to accept/refuse/or redirect
- NIDS definition
- Network Intrusion Detection System/Software
- GAME: why use binary protocol?
- simpler, a text-based protocol requires more translations/parsing
- IP
- Internet Protocol, defines packet format
- Socket
- exists in software, creates a handle for network communication. consists of a number and a handle
- API
- Application Programmer Interface, used to give programmers simplified access to pre-programmed services (example: socket API)
- broadcast address
- 255s, found by performing a logical "OR" of a given address and netmask; special address that causes underlying system to deliver packet copy to all networked computers
- Network Topology
- the physical/logical network layout, including star, ring, and bus (Ethernet)
- What is a network
- group of connected computers able to exchange messages
- IP Masquerading
- built into Linux NAPT, a workaround to help solve IP namespace issues
- GAME: what is a Message?
- packet sub-type, a specific packet is both Type and Message, for example PACKET_TYPE_CHAT (type) and PACKET_CHAT_MSG_SHOUT (message) or PACKET_CHAT_MSG_WHISPER
- WAN
- Wide Area Network
- Hub/Switch Port
- a physical port
- protocol
- rules for how computers exchange messages
- TCP/IP Layers
- PDNTA: 1-Physical layer, 2-Datalink layer, 3-Network/internet layer, 4-Transport layer, 5-Application layer
- HTTP Versions
- HTTP/1.0 or HTTP/1.1
- Serial
- RS-232 standard, one data line per direction
- GAME: Packet.h types
- PACKET_TYPE (ELSCCNAASBS); PACKET_TYPE_ (ERROR, LOGIN, STATS, CHAT, COMBAT, NAVI, ANNOUNCE, ADMIN, SIGNUP, BANK, STORE)
- LAN
- Local Area Network
- SMTP Reserved Port
- TCP 25
- MIME
- Multipurpose Internet Mail Extensions, way of encoding variable names and values, used in SMTP to specify subject, attachment, etc.
- FTP
- File Transfer Protocol, a network protocol used to transfer data over a network
- Parallel
- multiple data lines per direction
- IMAP
- Internet Mail Access Protocol, used to retrieve mail
- DNS
- Domain Name Service/Server; a hierarchy of servers, resolves an IP address
- stream
- continuous stream of data without distinct sequence breaks, such as IPTV, VOIP, online games, etc.
- Compare and contrast Serial vs. Parallel
- both are used to send and receive info between computers, serial sends or receives one data line at a time and is cheaper, parallel sends and receives multiple data lines at same time and is more expensive
- router/gateway
- basic computer attaching 2 or more networks, forwards packets according to routing table info, a.k.a. packet switch
- Find network and broadcast addresses from IP: 192.168.128.37 and netmask: 255.255.255.0
- Network address: 192.168.128.0., Broadcast address: 192.168.128.255
- How are email headers encoded?
- MIME encoded
- HTTP Reserved Port
- TCP 80
- Compare and contrast TCP vs UDP
- UDP is faster but less reliable than TCP, TCP checks if each packet arrived UDP does not check, UDP does not guarantee reliability or ordering, UDP apps include DNS IPTV, VOIP, online games, etc.
- TCP
- Transmission Control Protocol, provides applications with connections-oriented communications service
- IP Address
- Internet Protocol Address, a 32-bit address assigned to computers using TCP/IP protocols, sender must know destination IP address to send a packet
- Compare and contrast router vs gateway
- Both connect two or more networks, gateways are generic packet switchers and may use multiple protocols, routers are a specific gateway using IP protocol
- switch
- smart electronic device connecting LAN network devices, uses destination address in a frame to determine which computer should receive that packet
- Compare and contrast DHCP and SNMP
- Both work with networks, but DHCP is about remotely acquiring a network address, while SNMP is about getting/manipulating network device settings
- bind
- connects socket to a port
- DNS
- Domain Name Service, used to translate website names into IP addresses
- MAC
- Media/Medium Access Control, the physical hardware address, quasi-unique number for specifying a network adapter
- FTP's two connections
- one for commands (port 21), one for transfers
- packet
- a small, unique, distinct information unit (data block) sent across networks, usually many packets are sent in response to requests, contains header identifying sender and recipient and payload containing data
- Compare and contrast packet vs stream
- both used to send and receive data, packet is a vaguely defined block of data (TCP packet is specific), stream is an open pipe without distinct sequence breaks
- Find network and broadcast addresses from IP: 64.233.187.99 and netmask: 255.0.0.0
- Network address: 64.0.0.0, Broadcast address: 64.255..255.255
- DHCP
- Dynamic Host Configuration Protocol; remotely acquire network address, based on BootP but pertaining to network devices
- POP3
- Post Office Protocol version 3, used to retrieve mail
- GAME: what is a Type?
- packet type or category, for example Error, Login, Stats, Chat, Combat, Admin
- NAPT
- Network Address Port Translation; router dynamically rewrites ports and IP address so multiple computers can share same IP address and port