TCP/IP Exam
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Outline - Title
OutlineCondensed - Title
Bold - Section
Underline - Subsection
Italic + Underline Sub - sub section
•Bullet - point
Italic - glossary
//Sx and //Ex - Start and End of Chapter x
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ping, tracert, ARP, ipconfig /[all][review], nbstat -[c][R],
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//SS I Fundamentals
//S1 The TCP/IP Exam
Chapter 6 Subnet Tables
•Identify valid network configs, for given scenario
•Configure subnet masks
•On NT server, configure TCP/IP to support multiple network adapters
•Configure NT server as IP router
•Configure scopes using DHCP mgr
•Install and Configure DHCP relay agent
•Select appropriate srvices to insytall when using TCP/IP on NT server, for given scenario
•Install and Cionfigure WINS server
•Run WINS on a multihomed PC
•Import LMHOSTS files to WINS
•Configure static mappings in the WINS db
•Configure WINS replication
•Configure HOSTS and LMHOSTS files
•Install and configure DNS serviceon NT server
•Integrate DNS with other name servers
•Connect a DNS server to a DNS root server
•Configure DNS server roles
•Configure SNMP
•Configure and support browsing on multiple domain routed network
•Indentify which utility to connect to a TCP/IP UNIX host, for a given scenario
•Configure a NT server to support TCP/IP printing
•Configure RAS srver and Dail-up Networking for use on a TCP/IP network
•Identify which tools to monitor TCP/IP traffic, for a given scenario
•Diagnose and resolve IP addressing problems
•Diagnose and resolve name resolution problems
•Identify the correct TCP/IP utility to use to diagnose IP configuration problems
•Use TCP/IP utilites to diagnose IP configuration problems
•Dynamic Host Configuration Protocol (DHCP)
•Windows Internet Names Service (WINS)
•NetBIOS (Basic In Out System)
•Host Name Resolution
//E1 The TCP/IP Exam
//S2 A TCP/IP Primer
Where
Control Panels->Network->Protocols tab->Add TCP/IP
Acronyms:
ARP - address resolution protcol, [gets hardware (ethernet card) adress from IPA]
* DHCP - dynamic host configurAation protcol
* DNS - domain name service
DOD - dept. of defense modle
FTP - file transfer protocol [user authentication]
ICMP - Internet control message protocol
InterNIC - internet network informtion center
IP -internet protocol
OSI - open systems interconect
x RARP - reverse adress resolution prorcol, [gets IPA from hardware (ethernet card) adress]
RFCs - request foro comment
x SMTP - simple message transfer protocol
* SNMP - simple network management prototl
TCP - transmission controll protocol
x TFTP - trivial file transfer protocol, [NO user authentication]
UDP - user datagram protocol
x WAIS - wide area information server
IGMP - Internet Group Management Protocol
Others:
x ping
Telnet
•Must learn acronyms
•Learn basics of all protocols, esp. SNMP
•Basic OSI
•Forget WAIS, Gopher, Archie, WWW and HTTP, TFTP, SMTP
•Little FTP
•Basic purpose of layers in TCP/IP
command line (dos:ftp)/graphical (nt,mac:cuteFTP,fetch)
Access:Anonymous(anonymous/email) - most secure - and username/password - can be hacked
FTP sends unencrypted text - insecure
Reference models, describing the layers of each protocol, are needed for industry standards to provide compatible hw and sw.
Functional components - layers.
(Covered in Networking Esentials MCSE)
ISO-OSI, 70s, Seven layers.
Performs specific tasks in co-op with layers immediately above and below.
All People Seem To Need Data Procesing
•Application : Start and End of communication, original user data presented to end user.
•Presentation:Data translation (per platform), encrytion, compression
•Session: enables applications to start/use/end connection - session. Informs terminals location and duration of Tx
•Transport : similar to datalink, correct frame size management
•Network: determines path, router
•Datalink: frame management, error free transfer of frames
•Physical : binary data conversion:electrical,mechanical,optical interface
Please Do Not Throw Sausage Pizza Away
60s, Four layers, Equivalent functionality.
Enables vendors to make TCP/IP compatable devices, discribes layer purpose and service to layers above and below.
•Application : . Users/Apps interact w/ this layer. Primary Protocols/Applications run here determine how lower levels function and use their services (ping uses ICMP - Internet Layer)
"Application Helper Layer" - Printer Support, Resource Sharing, Remote File Access.
•Transport : Provides comms between hosts, data delivery to Application. Frame Sequencing , Error Detection & ACKs.
2 protocols : TCP (precise) or UDP (speed)
•Internet : Determines route, uses IP to get physical hardware adress - logical adress (IPA or host name)
•Network Interface : Just above hw. Puts data frames onto and picks data off nw, via nw adapter.
Never Invite Tourists Abroad
Number of Components part of TCP/IP model, distributed thru' model layers, depend ing on task. Some compnents of TCP/IP model are protocols, utilites (FTP), or services (DNS). Protocols maps to layers - except Network Interfae, adapts to various nw types.
utilities and services with which user interacts, no background stuff.
•FTP - utility (monitoring and troubleshooting). Must have FTP server to connect to. NT comes w/ client only. (APP or prtcl?)
•TFTP - not in exam , uses UDP
•SMTP - not in exam, transfers e-mail
•*DNS - MS, resolves host names to IPA (32 bit), Internet usage, Servers stored names and Address, quieried by clients w/ just a name.
•*SNMP - Network admin, get status of nw devs are config and trouble shoot. MS Client only quieried via central nw maanagement PC, sw costs extra.
•ping - utility (monitoring and troubleshooting) - ICMP echo request and echo reply packets. To check connection - No questions on ping.
•telnet - utility (monitoring and troubleshooting) - Connectivity command , terminal emulation for PC. From dumb terminlas telnetting to main frame. Configure routers, free with NT
Not for transport: frame sequenci9ng error detection an acknowlegment
"Inspection of data (to be) transferred"
•TCP - Ensures Reliable connection-orientated ordered comms, incorrect data order re order, not recieved retx. Virtual circuit, two way comms, both negociate, or one sided, termination of onnection.
•UDP - no guarentee or order nor receipt, no acks : fast
Will be tested.
•IP - Core, adresses packet (source and destination IPAs) [in header], and sends. Other PCs inspect to see if for them.
•ICMP - essential diagnostics and error reporting, echo request and echo reply packets: Request response and Update on route to destination. ping and tracert
•ARP - enables comms w/ just name and not physical address. To send info, needs hardware address, if not in recent cache (few minutes), sends out name and quiery. Named PC responds with nw card address.
•x RARP - not in exam. hardware address to IPA. MS uses DHCP instead.
•*DHCP - Medium large networks. Saves manual config of each workstation.
•IGMP - Gives LAN routers info of multicast host groups. Multicasting: Data routed to multiple hosts simultaneously.
//E2 A TCP/IP Primer
//S3 IP Address Resolution Protocol
Least understood, important : Gets hardware address from given IPA
•Function of ARP
•Why, Where and How ARP resolves addresses: esp. how ARP gets HWA of remote host
•ARP Cache: When consulted, purged
•What can go wrong : Common problems
•6 2 digit hex chars at manuf.
•ipconfig /all
•Hardware Address
-Network Interface Card (NIC) address
-Media Access Control (MAC) address : Most common. MAC, one of DataLink layer's 2 sub layers, deals with network interface card.
-Physical address
-Network Adapter card address
-Ethernet address
•HWA is unique & hard coded, use as source and destination around world.
-HWA difficult to remember
-HWA does not indicate which network
-can not be modified
•ARP converts NWA to IPA
•Destination NWA must be in header
1. TCP/IP puts HWA of dest. to header of packet to send
2. TCP/IP puts HWA of source, so destination can reply
3. Each host on nw inspects header to check for it's HWA - if yes, host sends pkt. up thru' layers.
4. Subnet mask determines which network dest. is on. - IF local, destination HWA put in packet header.
- IF remote, router HWA put in packet header.
5. When IP pkt arrives at destination network, ARP resolves HWA from IPA
*Will be exam on reolution on local and remote networks.
Also WINS and DNS [chpt9 & 10]
Must have hardware adress to communicate.
When host initialises itself on network, ARP broadcasts HWA and IPA.
If IPA already used then host is not initialed
Local if subnet mask determines that source and destination IPAs are on same portion of network.
If local then ARP resolves HWA from destnation IPA, for the header, while packet is still at source.
Resolution uses ARP request and ARP reply.
1ping
2Determines IPA is local, source ARP cache is checked
3If no mapping , ARP Request sent out.
4All hosts check to see if IPA is there own
5Destination matches its IPA
6Sends back ARP Reply w/ dest. HWA
7Both source and destination ARP caches updated w/ correct map
8 Comms init'd.
Remote if reached via Routers. Compare Subnet Mask and source IPA with destination IPA. Not dissimialr to Local resolution.
*ARP must resolve HWA of each Router. Hop between routers.The destination HWA of the sent packet is the first router's. Resolved as for local.
To comm. IPA of destination m/c must be resolved to HWA. Destination m/c may be next router to reach host.
1 Remote IPA 118.14.33.187, determined from ping
2 Routing Table of source m/c checked for route to Destination Network.
-route: source ARP cache checked for Router HWA mapping.
-no route: source m/c checks ARPcache for mapping of Default Gateway (118.14.126.1)
3 If No mapping for default gateway, ARP Request for Default Gateway
4 Router responds to ARP Request w/ HWA
5 Sopurce sends final destination IPA to router for router to determi e which network router is on.
6 Router sees if IPA is local or remote.
7 If remote router checks its Router Table for route to destination network. ARP cache also checked for HWA map for next router.
8 If No mapping for next router, Router ARP Request for Next Router. Next Router replies. Packet sent to next router.
9 Final destination host replys to source w/ HWA.
10 As source is remote then dest, must consulte routing table. ARP cache checked for [first from final] router HWA map.
11 No mapping for [first from final] router, Final Destination ARP Request for [first from final] Router.
12 Router replies. Packet sent to router.
Packet returns to source.
When packet arrives at destination router, destination IPA in header changed to eflect next router or final destination host, if reached the destination network.
Local m/c table w/ all appdress mappings comppleted in current session. Increases performance.
Header: Souce & Destyination IPA and SOurce and Dest. HWA
Not permanent, stored in temporary RAM
Decreases resolution time.
Decreases network traffic.
•Before packet sent
•After packet arrived at router
•When final destination host replies
ARP -a [-g]
-s store
-d delete
Last 2 minutes
If accessed stay for ten minutes total then purged; else purged.
To reduce size of cache, and maintain efficiency
Static
Added manually ARP command
Frequent candiddates.
May be updated automaticaly if resolution changes.
???Book confusion?????
router table
dynamic/not dynamic
???Book confusion?????
•Duplicate IP addresses
-Incorect mapping goes into cache
-second host shouldn't work, other nws maybe, will cause ongoing probs
-DHCP prevents this. Manually set printers, servers etc. Exclude from pool of valid addresses.[chpt8]
•Incorrect submasks [chpt6]
-Reduces nw performance thru' continual broadcasting [rx and processing].
•ipconfig /all [chpt13]
-ipa
-manual/dhcp?
-ipa unique?
-ipa<->hwa
•arp -a
-add/modify/view/delete entries
-check correct mapping if all else fails,use ipconfig /all to get ipa<->hwa
-static for regular hosts
-delete an incorrect entry (pkts sent continually to incorect hwa of destination host)
•ping
-gets reply
-verify connectivity
-determine if physical/addressing/name resoultion
//E3 IP Address Resolution Protocol
//S4 Host Name Resolution
Let's Have Dinner Next When Baby Leaves
//E4 Host Name Resolution
//S5 NetBIOS
Revise:
• Configuring NetBIOS names and service types
• Identifying NetBIOS name resolution process
TCP/IP, NetBEUI,
IPX/SPX
net config
net view
net use
15 charatcers + 16th Hex suffix
Not case sensitive, uppercase
<00h> Workstation
<03h> Messenger
<20h> Server
1 NetBIOS name cache (local)
2 WINS
3 b-node broadcast
1 LMHOSTS file (local)
2 Host Name (local)
3 HOSTS file (local)
4 DNS
b-node : broadcast
p-node : peer to peer
m-node : mixed
h-node : hybrid
enhanced b-node : consults LMHOSTS file too
Microsoft enhanced - not used
//E5 NetBIOS
//ES I Fundamentals
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