When examining the communications infrastructure and the major problems that are associated with using current technologies we see that the point of new technology is to over come deficiencies of current technologies.
The world is moving at fast pace, processors and applications just keep getting faster and faster, so we look at data communications and how it can improve the movement of information within a networked environment.
This chapter gives the general overview of the emerging technology to meet needs of applications.
Needs for Services
The Past
Development of high-speed inexpensive computers to meet the needs of the average person. This opened a vista to new powerful application. Examples of the applications that may be used are interactive real-time simulations, three dimensional modeling and color images.
The T1/E1 Legacies
1970s & 1980s = 1.5 to 2.048 Mbs
- T1/E1 meet the needs for most user applications
VPN - Share communications channels with other users
Switches - Relay traffic from multiple users.
Frame Relay fast packet service
-Lets the user support error recovery
-bandwidth and demand services
-data applications and some voice applications
-Suppose to solve WAN bottle neck services
MAN IEEE Standard 802.6
-distributed queue dual bus (DQDB) protocol to support integraded networks for multimedia applications
-interconnects LANs accross WANs
Switched Multimegabit Data Service (SMDS)
-Relies on the MAN technologies
-provides public high-speed transport system US and Eurpose
Services - highspeed ata applications that require bursts for high-speed data applications that require bursts of high bandwidth transmission for applications.
Such as, file transfer, CADéCAM, and imaging.
Asynchronous Transfer Mode
- part of B-ISDN solution
- cell relay technology
includes - high speed
- multiplexing and switching services for voice, data and video applications
Cell in ATM and IEEE 802.6 (MAN)
802.6 = basis of SMDS
CELL vs FR
Cell at the CPE a computer or PBX
which can be variable
is - segmented into smaller fixed length units called cells
5 header 48 payload
Supports transmission and reception of voice, video data and other applications
Interests = Large companies that have developed multiple networks to handle transmission schemes.
Why do we prefer cell
Cell is better then variable length frames, which provides the delay to be predictable in fixed length frames with the performance in the network then with variable length frames
-ATM queuing is done inside switch
-Fixed length buffers more easier to manage then variable.
-Cell relay has superior Quality of Service.
Wide spread commercial inception of computer and communication's networks in the 1960`s
1970`s - Communications archietecture was all software
Typically
Physical Layer = hardware
Datalink Layer = software
Late 1970`s early 1980`s
implemented into hardware some of the Data Link functions
Fostered HDLC which would
lead to -Link Access Procedure Balanced (LAPB)
-Link Access Procedure For the D channel (LAPD)
-Chip sets and firmware
Thats all I am going to introduce for now next post will continue Chapter 1, in later chapters Uyless Black goes into detail with every protocol mentioned here and that will be in next post. So don`t be to overwhelmed, I know I was the first time I read half the book.
Little note to me: Ch1 Pg5
Saturday, March 22, 2008
Friday, March 21, 2008
About New Postings
Due to the Hands On Work in my program I will only be posting relevant information on every lecture for my courses.
I will be focusing on, Data Communications,
Book:
Emerging Communication Technology by Uyless Black
that will gradually move to
IP Routing Protocols by Uyless Black.
Any relevant information to courses within the Computer System Technology Diploma will be posted with the Title of the Course Code and Topic, mostly theory.
Note: Future online posting will change.
I will be focusing on, Data Communications,
Book:
Emerging Communication Technology by Uyless Black
that will gradually move to
IP Routing Protocols by Uyless Black.
Any relevant information to courses within the Computer System Technology Diploma will be posted with the Title of the Course Code and Topic, mostly theory.
Note: Future online posting will change.
INT420 - Secure Socket Layer
Encryption on the exam,
When we want to send and encrypt data securly, the basic process
take the original data and an encryption key, random string of
characters, random very large number
take the data and teh encryption key and put them into a encryption alogrithem or program
what you get out of that in encrypted data, in order to read that data
you take the encrpyted data and a decryption key put it through the same algorithem/program,
then you end up with the original data,
Two basic models
symitrical encryption - a shared secret
with semitrical encryption you have a single key, and you use the same key to encrypt and decrypt the data
asymetrical encryption - public/private key pairs
two keys, that are designed to work togeter, a public and a private key, in this encryption you encrypt with one or decrypt with the other, u must use the other part of the pair, en pri / de pub
Client Machine Alice
AB-----
Connected to the Net
----AB
Client Machin Bob
using this semitrical encryption alas would need a copy of the key and bob will need the copy of the same key
Its good cause its fast,
you can generate a new key for every process/
---_FAST SECURE__----
Problem how do they get the copy of the same key, especially over a line, the problem with session key how do you get the key on both sides
in the past, generate it on place and take it from one to the other and install but again thats a 1 kind operation.
Asymtrical alias an encrypted connect4ion for bob, he has the public key B and a private key B the private key never leaves bob,
BOb takes his public key gives it to aliace, she encrypts the data with the public and encryps with the private key,
so the communicatiosn going back to alice are not secure, when we encrypt wioth the private anyone can read it
so its not good coming back in the opposite direction but it does have a purpose,
When he sends it to alice and has the private, what does this prove to us anyone can read what bob is sending, it can only have only come from bob. Because bob only has the private this is called a digital signature, anyone with the public key can read the private key but it must come from that source,
its use for authentication as a signature
Alice can gen4erat her own public/private send it to bob send it and she can use it, heres the problem its slow and alot of work, and somewhat more compicated then it needs to be, in the internet when we want to secure over the wweb we use
SSL ---- secure socet layer, you know this from https
SSL uses all the things that were discussed above, this is how it essentially works
Bob the server alice the client,
in order to facilite encrypted communication, bob needs a public and a private key for bob, now
the admin of bob wneeds a 3rd party company to create a certificate to tell the company this is the company, they take the public keye
they take the public key and send it to CERTIFICATE AUTHORITY, dozens of company's that do this
CERTIFICATE REQUEST, name server e-mail the FQDN all info about the orginations and the computer along with the public key,
the certificate authority preforms sum auth then creats a certificate contains all the info from the certificate request + bob public key then the certificate signs it with their private key, so its digitally signed through the CA.
SSL connection
Alice sends a httpds conn to bob then he says ok then sends the certificate and it contained the public key and the didtal sign of the CA alice reciuves the certificate alices browsers is already wiiht the key of all the private ca's auth, now we accept that public key as coming to bob
BOb has his private key and alice has his public key now alice generates a symettrical key thats only good for this session and encrypts using bob public key, bob is the only way he can use it cause he has a private key
Conenection to his web server his e-mail server it puts the https yellow bar and the pad lock
if you go to Tools page info
You look at the page info and you look at security it tells the identify has been varified by Equifax
View the certificate
In the LAB
Re-install apache to include SSL you need to isntall it into a diff directory you will install OPEN SSL, allows you to generate pub and private keys and request and authority, install apache fresh,
M
M
M
we use to for trust, and the mechinism for a public key then facilitae a session key, then they use that session key
When we want to send and encrypt data securly, the basic process
take the original data and an encryption key, random string of
characters, random very large number
take the data and teh encryption key and put them into a encryption alogrithem or program
what you get out of that in encrypted data, in order to read that data
you take the encrpyted data and a decryption key put it through the same algorithem/program,
then you end up with the original data,
Two basic models
symitrical encryption - a shared secret
with semitrical encryption you have a single key, and you use the same key to encrypt and decrypt the data
asymetrical encryption - public/private key pairs
two keys, that are designed to work togeter, a public and a private key, in this encryption you encrypt with one or decrypt with the other, u must use the other part of the pair, en pri / de pub
Client Machine Alice
AB-----
Connected to the Net
----AB
Client Machin Bob
using this semitrical encryption alas would need a copy of the key and bob will need the copy of the same key
Its good cause its fast,
you can generate a new key for every process/
---_FAST SECURE__----
Problem how do they get the copy of the same key, especially over a line, the problem with session key how do you get the key on both sides
in the past, generate it on place and take it from one to the other and install but again thats a 1 kind operation.
Asymtrical alias an encrypted connect4ion for bob, he has the public key B and a private key B the private key never leaves bob,
BOb takes his public key gives it to aliace, she encrypts the data with the public and encryps with the private key,
so the communicatiosn going back to alice are not secure, when we encrypt wioth the private anyone can read it
so its not good coming back in the opposite direction but it does have a purpose,
When he sends it to alice and has the private, what does this prove to us anyone can read what bob is sending, it can only have only come from bob. Because bob only has the private this is called a digital signature, anyone with the public key can read the private key but it must come from that source,
its use for authentication as a signature
Alice can gen4erat her own public/private send it to bob send it and she can use it, heres the problem its slow and alot of work, and somewhat more compicated then it needs to be, in the internet when we want to secure over the wweb we use
SSL ---- secure socet layer, you know this from https
SSL uses all the things that were discussed above, this is how it essentially works
Bob the server alice the client,
in order to facilite encrypted communication, bob needs a public and a private key for bob, now
the admin of bob wneeds a 3rd party company to create a certificate to tell the company this is the company, they take the public keye
they take the public key and send it to CERTIFICATE AUTHORITY, dozens of company's that do this
CERTIFICATE REQUEST, name server e-mail the FQDN all info about the orginations and the computer along with the public key,
the certificate authority preforms sum auth then creats a certificate contains all the info from the certificate request + bob public key then the certificate signs it with their private key, so its digitally signed through the CA.
SSL connection
Alice sends a httpds conn to bob then he says ok then sends the certificate and it contained the public key and the didtal sign of the CA alice reciuves the certificate alices browsers is already wiiht the key of all the private ca's auth, now we accept that public key as coming to bob
BOb has his private key and alice has his public key now alice generates a symettrical key thats only good for this session and encrypts using bob public key, bob is the only way he can use it cause he has a private key
Conenection to his web server his e-mail server it puts the https yellow bar and the pad lock
if you go to Tools page info
You look at the page info and you look at security it tells the identify has been varified by Equifax
View the certificate
In the LAB
Re-install apache to include SSL you need to isntall it into a diff directory you will install OPEN SSL, allows you to generate pub and private keys and request and authority, install apache fresh,
M
M
M
we use to for trust, and the mechinism for a public key then facilitae a session key, then they use that session key
Tuesday, November 20, 2007
OPS335W11
OPS335
ubuntu apt-getn install apache
info
sudo apt-get install bind
samaba 3 ways to act as a client
1. you can use a file/web browser that understands the smb protocol
Konquere understands the ftp http and smb protocols
2. command : smbclient
get
put
3. As root do the mount
mount -t cifs //matrix/john.selmys /mnt/banana
cifs driver uses encryption for the password, matrix samba server only accepts passwords in plain text
Assignment 3 (bonus)10%
Write up a document how you will set up a backup/restore system for a client
DNS
1978-79 tcp/ip started
two universities a line between the two, for U1 and U2
then came U3 and came online paying full price
/etc/hosts
each had a host file, information matches forward and reverse mapping, '
registered
1984 - DNS
root servers = 13
Too many request is a DOS denial of service
Vince Surf
Lab 9 Install Bind
ubuntu apt-getn install apache
info
sudo apt-get install bind
samaba 3 ways to act as a client
1. you can use a file/web browser that understands the smb protocol
Konquere understands the ftp http and smb protocols
2. command : smbclient
get
put
3. As root do the mount
mount -t cifs //matrix/john.selmys /mnt/banana
cifs driver uses encryption for the password, matrix samba server only accepts passwords in plain text
Assignment 3 (bonus)10%
Write up a document how you will set up a backup/restore system for a client
DNS
1978-79 tcp/ip started
two universities a line between the two, for U1 and U2
then came U3 and came online paying full price
/etc/hosts
each had a host file, information matches forward and reverse mapping, '
registered
1984 - DNS
root servers = 13
Too many request is a DOS denial of service
Vince Surf
Lab 9 Install Bind
Monday, November 19, 2007
DCN386 Frame Relay
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/frame.htm
What does Frame Relay do and how does it work?
Frame Relay - is a modern datacom protocol,
-created to handel a specific job
all protocols specific job
X.25 - Users for small amounts of data infrequently
However
Introduction to LAN 1990
-Require emerged, link Remote area networks together
- LAN 100mil bps
How can you connect this to connect two offices together?
X.25 - top speed in canada 64K----around----not sure-----
Frame Relay, equipment such as routers,
-Have serial ports
-Routers send data using HDLC, ciscos default
HDLC is a module, if you want FameRelay you get cisco to get you the Frame Relay Module
First out of the five.
-Frame Relay perfect protocol for intercommunication for LAN
-its good cause its incredibly fast
Why is frame relay fast?
-It doesnt do anything except transmit data
-Does do error checking, but if their is an error it dumps the frame
-The point is speed
-----------
X.25 do 20 seperate operations, so the packet is preserved and protects
-----------
Frame Relay devices do two things with every frame
-Validate it, error checking, dumps packet if error
-Validate the destination address, dumps it if it dont know it
-It makes sure every frame ZIPS through the network
--We let the end connections worry about the frames.
Where did Frame Relay come from?
A small part of a big initiative put by the ITU
In the future full digital everything
----------
Build the international digital service known as
ISDN
Essentially it failed
ISDN puzzle was examined by 4 companies and saw value in a little piece
Novel Telecome
Cisco
....
They developed the little piece called FrameRelay
-----------------------
Started an organization called FrameRelay Forum,
www.frforum.com
-----------------------
How does it work?
-First confusing thing
-Frame Relay is a DataLink Layer Protocol
----------------------
Phone companies have pre-build Frame Relay networks
ex: every bell office has routers that can handel FR
Idea customers can call bell and attach them into the FR cloud
---------------------
If you have a router of ur own u can take out the HDLC module and put in a FR modeuls
--------------------
Most orginations use the shared FR bell network
--------------------
Bell uses HIgh speed FIbre-optics
--------------------
Frame Relay Format:
f | Control | f
Flags are used when the amount of data is variable
-No specification of data unit
Because their is no knowledge of the variable it puts Flags around the data.
------------------------
Ethernet does 1500bytes
-----------------------
Frame Relay - Combines the address and control field, for the test call it Control
Control Field --- 2 3 or 4 bytes long
^ is known to use
Remember to understand a protocol look at the control field
2 bytes - 16 bits
first 6 bits
- Part of the protocols addressing scheme
second 4 bits
- Also part of frame relay addressing scheme
They are called the DLCI
Data-Link Control Id
| DLCI | DLCI |
In byte one its called the command response bits,
-useless no function
Last bit in byte one is the Extended address
-simply means their another byte incolved
In byte 2 theirs an extended address
- if the EA is a 1 theirs no more addressing
3 bits unaccounted for
BECN -Back Explicit COngestion Notification
FECN -Forward Explicit congestion Notification
DE -Disguard Eligibility
DE - is a key feature
-----------------------------------
Two organization
Have offices Vancouver and Toronto
Happy NEtworking People
-Want to use Bell Canada Frame Relay Network
-Big expensive Routers with FrameRelay Modules
-Bell network Extremely Fast Fibre Optic Cables
TD gets the Routers to the network
Scotia GIrl gets her Router to the network
How will bell build this network
-Bell Canada has a special device at the boundry called a FRAD
FRAD - Frame Relay Assembler Disasembler
Its at the parameters of the cloud not inside the cloud, thats how they attach themselves
to the cloud
SB and TD different data-
How does bell invoice?
-When you phone bell he asks how much data u going to send into the network
-Frame Relay was designed to handel bursts of data
-Designed to connect LANs
20% locally 70% lan
Want to know how big the bursts is going to be,
Range from 64K bps
128k BPS
etc...
Networker, does analysis how much data is going to be tranmitted
and a conclusion to how much data going to be sent and received
Bell bills towards the K
--------------------------------
Frame Relay simply moves the data to the next router, quickly as possible
--------------------------------
FRAD -- Bell canada programs the FRADS
How will bell build this network
-Bell Canada has a special device at the boundry called a FRAD
FRAD - Frame Relay Assembler Disasembler
Its at the parameters of the cloud not inside the cloud, thats how they attach themselves
to the cloud
--------------------------------
DiscardEgibility - gets turned on when you send bursts of data
Bell canda calls bursts of data CIR - COmmunited Information Rate
-------------------------------
Frame Relay has one trick, if it becomes congested, will drop the frame.
-----------------
Getting customers to commit to the FRAD rate if you congest(go over the) CIR rate.
-----------------
BECN -Back Explicit COngestion Notification
FECN -Forward Explicit congestion Notification
When a device gets congestions it turns on BECN and FECN,
Whole idea - intended by frame relay forum, user device would notice
frames will arrive, it was hoped somebody develop a
program to have their own flow control to control the data coming in
Everyone ignored these bits.
----------------
Subnetting:
11.0.0.0
Require 5000 Subnets
00000000.00000|000.00000000
10.0.0.0 internal address
Classless /26
What does Frame Relay do and how does it work?
Frame Relay - is a modern datacom protocol,
-created to handel a specific job
all protocols specific job
X.25 - Users for small amounts of data infrequently
However
Introduction to LAN 1990
-Require emerged, link Remote area networks together
- LAN 100mil bps
How can you connect this to connect two offices together?
X.25 - top speed in canada 64K----around----not sure-----
Frame Relay, equipment such as routers,
-Have serial ports
-Routers send data using HDLC, ciscos default
HDLC is a module, if you want FameRelay you get cisco to get you the Frame Relay Module
First out of the five.
-Frame Relay perfect protocol for intercommunication for LAN
-its good cause its incredibly fast
Why is frame relay fast?
-It doesnt do anything except transmit data
-Does do error checking, but if their is an error it dumps the frame
-The point is speed
-----------
X.25 do 20 seperate operations, so the packet is preserved and protects
-----------
Frame Relay devices do two things with every frame
-Validate it, error checking, dumps packet if error
-Validate the destination address, dumps it if it dont know it
-It makes sure every frame ZIPS through the network
--We let the end connections worry about the frames.
Where did Frame Relay come from?
A small part of a big initiative put by the ITU
In the future full digital everything
----------
Build the international digital service known as
ISDN
Essentially it failed
ISDN puzzle was examined by 4 companies and saw value in a little piece
Novel Telecome
Cisco
....
They developed the little piece called FrameRelay
-----------------------
Started an organization called FrameRelay Forum,
www.frforum.com
-----------------------
How does it work?
-First confusing thing
-Frame Relay is a DataLink Layer Protocol
----------------------
Phone companies have pre-build Frame Relay networks
ex: every bell office has routers that can handel FR
Idea customers can call bell and attach them into the FR cloud
---------------------
If you have a router of ur own u can take out the HDLC module and put in a FR modeuls
--------------------
Most orginations use the shared FR bell network
--------------------
Bell uses HIgh speed FIbre-optics
--------------------
Frame Relay Format:
f | Control | f
Flags are used when the amount of data is variable
-No specification of data unit
Because their is no knowledge of the variable it puts Flags around the data.
------------------------
Ethernet does 1500bytes
-----------------------
Frame Relay - Combines the address and control field, for the test call it Control
Control Field --- 2 3 or 4 bytes long
^ is known to use
Remember to understand a protocol look at the control field
2 bytes - 16 bits
first 6 bits
- Part of the protocols addressing scheme
second 4 bits
- Also part of frame relay addressing scheme
They are called the DLCI
Data-Link Control Id
| DLCI | DLCI |
In byte one its called the command response bits,
-useless no function
Last bit in byte one is the Extended address
-simply means their another byte incolved
In byte 2 theirs an extended address
- if the EA is a 1 theirs no more addressing
3 bits unaccounted for
BECN -Back Explicit COngestion Notification
FECN -Forward Explicit congestion Notification
DE -Disguard Eligibility
DE - is a key feature
-----------------------------------
Two organization
Have offices Vancouver and Toronto
Happy NEtworking People
-Want to use Bell Canada Frame Relay Network
-Big expensive Routers with FrameRelay Modules
-Bell network Extremely Fast Fibre Optic Cables
TD gets the Routers to the network
Scotia GIrl gets her Router to the network
How will bell build this network
-Bell Canada has a special device at the boundry called a FRAD
FRAD - Frame Relay Assembler Disasembler
Its at the parameters of the cloud not inside the cloud, thats how they attach themselves
to the cloud
SB and TD different data-
How does bell invoice?
-When you phone bell he asks how much data u going to send into the network
-Frame Relay was designed to handel bursts of data
-Designed to connect LANs
20% locally 70% lan
Want to know how big the bursts is going to be,
Range from 64K bps
128k BPS
etc...
Networker, does analysis how much data is going to be tranmitted
and a conclusion to how much data going to be sent and received
Bell bills towards the K
--------------------------------
Frame Relay simply moves the data to the next router, quickly as possible
--------------------------------
FRAD -- Bell canada programs the FRADS
How will bell build this network
-Bell Canada has a special device at the boundry called a FRAD
FRAD - Frame Relay Assembler Disasembler
Its at the parameters of the cloud not inside the cloud, thats how they attach themselves
to the cloud
--------------------------------
DiscardEgibility - gets turned on when you send bursts of data
Bell canda calls bursts of data CIR - COmmunited Information Rate
-------------------------------
Frame Relay has one trick, if it becomes congested, will drop the frame.
-----------------
Getting customers to commit to the FRAD rate if you congest(go over the) CIR rate.
-----------------
BECN -Back Explicit COngestion Notification
FECN -Forward Explicit congestion Notification
When a device gets congestions it turns on BECN and FECN,
Whole idea - intended by frame relay forum, user device would notice
frames will arrive, it was hoped somebody develop a
program to have their own flow control to control the data coming in
Everyone ignored these bits.
----------------
Subnetting:
11.0.0.0
Require 5000 Subnets
00000000.00000|000.00000000
10.0.0.0 internal address
Classless /26
Monday, November 12, 2007
OPS335W10
whereis ls
/usr/share/man
manare like ls, echo, cat, mv all of these are in volume 1
all the manupages are compressed in gz, its easier to read a small file rather then
a big file to memory to read it,
ls.1.gz
all system administration commands are going to be .8
rezise2fs - volume 8
copy the ls command to your home directory so you have something to work with,
gzip-d ls.1.gz
ls -l
ls.1
now its in a language groff
groff - is a precurses to html
If you look at the html, from html you have xhtml, xml, all of these are markup languages,
before this if you go to 1960, IBM made up GML, they are nothing new they are just
derivatives, some where you will see roff, which is a form, then
groff(GNU free version)
MKGW 8 NOve 2007 mkgw.8 admin commands
mkgw \- Configure a linux host as a network gateway
groff -Tascii -man mkgw.8 |more <---intrepret what it looks like,
gzip mkgw.8
be root and copy it to volume 8 be sure its zipped /usr/share/man8/
On our floppy, we should have mkgw, mkgw.8.gz
show mkgw groff, listing of all the groff listeing and we should also show the man page
bash program as well
chmod 644 <----man page
-----------------------------------------
---------------------------------------
------------------------------------
----------------------------------
Distributed File Systems
All about file sharing, share files between two Dos Machines
The idea is:
Server Client
/
| | | | | |
home home
| |
| |
frank joker
| |
| |
stuff---------------------junk
Make a directory under junk
Connect stuff to junk
Make a file under junk "ABC" as the Server
Alot of things ot be set up to make this work
you have to know the IP address of both machines
1. IP of each machine
"FQDN"
2. Server needs a file sharing program
and-configured to allow the client to read or write or r/w
the stuff directory.
File sharing deamon or file sharing server
It will allow the client to read the directory
Withing our Server we have a file sharing program to allow the client to use this program
3. The client needs a program or software, to attach and use stuff(dir) from the server
^^^^^^^^^^Basic idea od DFS(Distributed File Systems)
The two systems we look at are
NFS - method of sharing files
SAMBA - method of sharing files
Network File System
-Developed by Sun Microsystems 1984
When did the first pc come out 1988,
versions for Dos and Windows,
-important to note,
b/c it was written so long ago it uses ports in a different way
Web Server
-Running Apache
-Port 80 (waiting for connections)-------1024---IE6 (WINXP)
|_1026___Firefox (FEdora7)
|_1024___Safari (MAC OSX)
In 1984 Sun did not use port numbers
-used sun numbers,
ex: SUN NFS Server Sun Client
\(directories)--8----------------8----\(directories)
-The numbers used have nothing to do with ports ^^
This is where
-Remote Procedure Call (RPC)
--We still use the sun numbers but software converst it to ports
When you jrun the server you have to run another program
that changes the number to ports.
man exports ----its in /etc/exports
- on the server side this file tells what directories are avaliable
to which clients & in what mode, read or write mode
Their is an example in the man page
id frank
----------------------
NFS SErver NFS Client(Fedora 7 Client)
-host abc joker on xyz
/home xyz (r,w) $su -
/etc/exports #mount -t nfs abc:/home /mnt
|_usually an empty dir used for mounting
|
# | |
joker clown
#cd /mnt/joker
#rm *
This wi9ll alow the person to do w.e.
If you put xyz (r,w) root_squash
so the rm will fail
or no_root_squash
Setting NFS
1. install NFS-server
2. edit /etc/exports
3. start nfs server
4. you change /etc/exports
5. Choice
- Stop & stop the NFS server
OR
#exportfs -a
-reread the exports file without restarting
READ bout NFS
Samba is different
- Andrew Tridgell -wrote Samba-1995 Microsoft - SMB (used for fily sharing -OLD)
-idea to work in a microsoft enviroment -CIFS (Common internet file system) *newer*
-use windows as a client
- use the share
- can become a client on linux and become a user share
-he also wanted linux with its own share and have
win1 win2 win3 machines just as though linux was windows box
Basically Samaba - A client and a Server, a client for windows shares and a server for windows shares
using smb protocol to see the files in their
konquer - shows file systems and a webbrowser
seneca subnet 142.204
LEARN NFS and
export, exportfs, NFSDEAMON, know how to config the files
Lab 8 is three parts,
Connectings to a Samba server- file sharing server using
cifs - file samaba system
Part One - Client
Part Two - Own Samaba server
testparm - check if syntax is correct
/usr/share/man
manare like ls, echo, cat, mv all of these are in volume 1
all the manupages are compressed in gz, its easier to read a small file rather then
a big file to memory to read it,
ls.1.gz
all system administration commands are going to be .8
rezise2fs - volume 8
copy the ls command to your home directory so you have something to work with,
gzip-d ls.1.gz
ls -l
ls.1
now its in a language groff
groff - is a precurses to html
If you look at the html, from html you have xhtml, xml, all of these are markup languages,
before this if you go to 1960, IBM made up GML, they are nothing new they are just
derivatives, some where you will see roff, which is a form, then
groff(GNU free version)
MKGW 8 NOve 2007 mkgw.8 admin commands
mkgw \- Configure a linux host as a network gateway
groff -Tascii -man mkgw.8 |more <---intrepret what it looks like,
gzip mkgw.8
be root and copy it to volume 8 be sure its zipped /usr/share/man8/
On our floppy, we should have mkgw, mkgw.8.gz
show mkgw groff, listing of all the groff listeing and we should also show the man page
bash program as well
chmod 644 <----man page
-----------------------------------------
---------------------------------------
------------------------------------
----------------------------------
Distributed File Systems
All about file sharing, share files between two Dos Machines
The idea is:
Server Client
/
| | | | | |
home home
| |
| |
frank joker
| |
| |
stuff---------------------junk
Make a directory under junk
Connect stuff to junk
Make a file under junk "ABC" as the Server
Alot of things ot be set up to make this work
you have to know the IP address of both machines
1. IP of each machine
"FQDN"
2. Server needs a file sharing program
and-configured to allow the client to read or write or r/w
the stuff directory.
File sharing deamon or file sharing server
It will allow the client to read the directory
Withing our Server we have a file sharing program to allow the client to use this program
3. The client needs a program or software, to attach and use stuff(dir) from the server
^^^^^^^^^^Basic idea od DFS(Distributed File Systems)
The two systems we look at are
NFS - method of sharing files
SAMBA - method of sharing files
Network File System
-Developed by Sun Microsystems 1984
When did the first pc come out 1988,
versions for Dos and Windows,
-important to note,
b/c it was written so long ago it uses ports in a different way
Web Server
-Running Apache
-Port 80 (waiting for connections)-------1024---IE6 (WINXP)
|_1026___Firefox (FEdora7)
|_1024___Safari (MAC OSX)
In 1984 Sun did not use port numbers
-used sun numbers,
ex: SUN NFS Server Sun Client
\(directories)--8----------------8----\(directories)
-The numbers used have nothing to do with ports ^^
This is where
-Remote Procedure Call (RPC)
--We still use the sun numbers but software converst it to ports
When you jrun the server you have to run another program
that changes the number to ports.
man exports ----its in /etc/exports
- on the server side this file tells what directories are avaliable
to which clients & in what mode, read or write mode
Their is an example in the man page
id frank
----------------------
NFS SErver NFS Client(Fedora 7 Client)
-host abc joker on xyz
/home xyz (r,w) $su -
/etc/exports #mount -t nfs abc:/home /mnt
|_usually an empty dir used for mounting
|
# | |
joker clown
#cd /mnt/joker
#rm *
This wi9ll alow the person to do w.e.
If you put xyz (r,w) root_squash
so the rm will fail
or no_root_squash
Setting NFS
1. install NFS-server
2. edit /etc/exports
3. start nfs server
4. you change /etc/exports
5. Choice
- Stop & stop the NFS server
OR
#exportfs -a
-reread the exports file without restarting
READ bout NFS
Samba is different
- Andrew Tridgell -wrote Samba-1995 Microsoft - SMB (used for fily sharing -OLD)
-idea to work in a microsoft enviroment -CIFS (Common internet file system) *newer*
-use windows as a client
- use the share
- can become a client on linux and become a user share
-he also wanted linux with its own share and have
win1 win2 win3 machines just as though linux was windows box
Basically Samaba - A client and a Server, a client for windows shares and a server for windows shares
using smb protocol to see the files in their
konquer - shows file systems and a webbrowser
seneca subnet 142.204
LEARN NFS and
export, exportfs, NFSDEAMON, know how to config the files
Lab 8 is three parts,
Connectings to a Samba server- file sharing server using
cifs - file samaba system
Part One - Client
Part Two - Own Samaba server
testparm - check if syntax is correct
Friday, November 9, 2007
DCN386W10
Alot of subnet questions in test 2
10.0.0.0
255.255.192.0
Question 2 Test2?
What is X.25 and how does it work?
X.25 when you see a letter then a number you know you are dealing with a protocol or equipement
ITU V.90
SDLC HDLC was last week, in PPP,
but their are different applications in this world,
Example.
A central computer, build a network for lottery ticket machines
X.25 solves specific application issue, if you have an application that sends data
infrequently you need X.25, lottery ticket, its a
Network Layer protocol, packet-switched network.
DCN386 only two network layer protocols, IP and X.25.
X.25 Network Packet Devices
X.25 designed to be a sutible protocol for people who want to send small amounts of data
infrequently.
All the telephone companies have all pre built x.25 network
Bell installed X.25 switched devices that spand all of canada
Easy to install and immediate benefit
Packet switching is already their and ready to be used. X.25.
Tip Top Tailers
because their all using the service is also shared, the second major benefit
It is extremely cost effecient. Pay for the service how much you use the network.
Based on a number of packets ur company of information
Packet is data send through a network layer protocol, IP and X.25 does this.
X.25 will take data and break it into a piece and will be a fixed lengthed, in Canada
Bell canada offeres serveral flavours, 90% of companies, of a basic frame size of 128bytes
this device will build you a packet and the max size is 128bytes.
Theory take user data, break it into pieces and sending it through the cloud.
How does the customer get the data into the cloud,
How does this work?
Simple their are 2 addresses involved,
1. is a real physical address
X121 - internation addressing scheme
-works and acts exactly like a phone number
-14byte address scheme
ha ha ha ha
Number can be up to 14 digits ex: 123-456-789-111
One of are job for us:
Supply the number of the cash register to dial into
The start of the day:
To set up the X.25, he(Manager) will send a packet from the tip top register called
-CALL REQUEST
-sent into the cloud
-goes to the switch, looks at the area local codes
-switch will select a route(path) through the network
The reciever will send a
-CALL ACCEPT
You now have a path way through a cloud,
-PathWay = Virtual Circuit
At the end of the day the guy turns the machine off, a last packet will be sent
-CALL CLEAR
No Longer a Virtual Circuit it is shut down
Another Day:
-CALL REQUEST
A Different Route is taken
-CALL ACCEPT
A Different Virtual Circuit
-------------
The X.25 machines are computer specialized in packet switching
-Lots of memory
Holding-Tables how to get to the Destination
--------------
First address is used in the CALL REQUEST
Once set up a second Address called:
-Virtual Circuit Address
-12 bits ~4096
---------------
VC-ID is sent = virutal circuit 1 - ALWAYS
-talking to 1 computer
---------------
Head office computers talk to Numerous Devices, thousands of lottery ticket machines-
-Identifying 4096 cicuits per physical line
---------------
X.25 Low Grade Low Speed Telecommunications Copper Wire ARgh!
---------------
When you phone bell and ask for an X.25 circuit, how many virtual curcuits on this physical line?
Pick a number -a number 0-4096
Never install more than
-32 virtual curcits in one physical line
----------------Rule of Thumb----------------------------
Cheap phone line!
------------------------------
Confusing Part:
Second thing that we will be asked when asking for the cuircut,
Do you want a private, switched or a combination of virtual circuit
-------------------
Two types of Virtual Circuits
-PVC (Private Virtual Circuit)
-SVH (Switched Virtual Circuits)
Depends on the packet a month you pay for it
--------------------
Another Cost a number of virtual circuits for a physical line
You want all permanent circuits, Bell will install a permanent route through the cloud
--------------------
Why would we used Switched hmmmm yea sooo
Three offices
Three networks
| | |
Every night the offices download the daily sales,
How many Virutal Circuits will i need on this line, One
All the networks in different locations and times will switch it,
-------------------
What if its modern and u want to install on real time, you would need three virtual circuits
and make them PVC
------------------------------------
-----------------------------------
---------------------------------
X.25 most endeering
Most Reliable protocol ever developed
-Error Handeling
-Flow Control Mechanisms
-----------------------------------
---------------------------------
-------------------------------
-Error Handeling (CRC)
------------------------------
-Max 128 bits
-Closest Circuit does error checking
-EVERY PORT IT'EL DO ERROR CHECKING
------------------------------------
------------------------------------
-FLOW CONTROL
- Any activity that prevents the loss of data
------------------------------------
------------------------------------
X.25 does not drop packets
-flow control mechnisms to stop sending data
--------------------------------------------
Because of speed its not used, ^ the things it does
--------------------------------------------
X.25 perfect for customers Infrequently
X.25 people looking over it!
X.25 1 component of a huge body of work
X.25 RULES PAD EQUIMENT TO ACCESS THE CLOUD
X.25 - small amounts data every so often ==== PERFECT ====
Once in the clout Dozen of protocols you can use
You can attached ur PC to Bells X.25 Network,
Phone connectiong, Packet Sender and Disembler (PAD)100$
--------------------------
X.3 - sepcification for what PADS do
X.75 - International speicification
--------------------------
X.25 is the slang to get into the cloud,
--------------------------
WEEK 13 TEST 2, IN THE LAB we are going to go the quiz, worth 10 %,
2 hours of subnetting
and Access Lists. ACL
GROOVEY LIKE GRAVEY
--------------------------
A packet arrives in a router, and the packet has the address 10.1.240.14, router does not revognize
the address and has the folling mask 255.255.240.0 , company network mask.
Class a 10.1.240.14
00000000.0000|0000.00000000
alL U HAVE TO do to see what subnet it belongs to?
00000001.1111|0000.00000000
subnet 31
10.0.0.0
255.255.192.0
Question 2 Test2?
What is X.25 and how does it work?
X.25 when you see a letter then a number you know you are dealing with a protocol or equipement
ITU V.90
SDLC HDLC was last week, in PPP,
but their are different applications in this world,
Example.
A central computer, build a network for lottery ticket machines
X.25 solves specific application issue, if you have an application that sends data
infrequently you need X.25, lottery ticket, its a
Network Layer protocol, packet-switched network.
DCN386 only two network layer protocols, IP and X.25.
X.25 Network Packet Devices
X.25 designed to be a sutible protocol for people who want to send small amounts of data
infrequently.
All the telephone companies have all pre built x.25 network
Bell installed X.25 switched devices that spand all of canada
Easy to install and immediate benefit
Packet switching is already their and ready to be used. X.25.
Tip Top Tailers
because their all using the service is also shared, the second major benefit
It is extremely cost effecient. Pay for the service how much you use the network.
Based on a number of packets ur company of information
Packet is data send through a network layer protocol, IP and X.25 does this.
X.25 will take data and break it into a piece and will be a fixed lengthed, in Canada
Bell canada offeres serveral flavours, 90% of companies, of a basic frame size of 128bytes
this device will build you a packet and the max size is 128bytes.
Theory take user data, break it into pieces and sending it through the cloud.
How does the customer get the data into the cloud,
How does this work?
Simple their are 2 addresses involved,
1. is a real physical address
X121 - internation addressing scheme
-works and acts exactly like a phone number
-14byte address scheme
ha ha ha ha
Number can be up to 14 digits ex: 123-456-789-111
One of are job for us:
Supply the number of the cash register to dial into
The start of the day:
To set up the X.25, he(Manager) will send a packet from the tip top register called
-CALL REQUEST
-sent into the cloud
-goes to the switch, looks at the area local codes
-switch will select a route(path) through the network
The reciever will send a
-CALL ACCEPT
You now have a path way through a cloud,
-PathWay = Virtual Circuit
At the end of the day the guy turns the machine off, a last packet will be sent
-CALL CLEAR
No Longer a Virtual Circuit it is shut down
Another Day:
-CALL REQUEST
A Different Route is taken
-CALL ACCEPT
A Different Virtual Circuit
-------------
The X.25 machines are computer specialized in packet switching
-Lots of memory
Holding-Tables how to get to the Destination
--------------
First address is used in the CALL REQUEST
Once set up a second Address called:
-Virtual Circuit Address
-12 bits ~4096
---------------
VC-ID is sent = virutal circuit 1 - ALWAYS
-talking to 1 computer
---------------
Head office computers talk to Numerous Devices, thousands of lottery ticket machines-
-Identifying 4096 cicuits per physical line
---------------
X.25 Low Grade Low Speed Telecommunications Copper Wire ARgh!
---------------
When you phone bell and ask for an X.25 circuit, how many virtual curcuits on this physical line?
Pick a number -a number 0-4096
Never install more than
-32 virtual curcits in one physical line
----------------Rule of Thumb----------------------------
Cheap phone line!
------------------------------
Confusing Part:
Second thing that we will be asked when asking for the cuircut,
Do you want a private, switched or a combination of virtual circuit
-------------------
Two types of Virtual Circuits
-PVC (Private Virtual Circuit)
-SVH (Switched Virtual Circuits)
Depends on the packet a month you pay for it
--------------------
Another Cost a number of virtual circuits for a physical line
You want all permanent circuits, Bell will install a permanent route through the cloud
--------------------
Why would we used Switched hmmmm yea sooo
Three offices
Three networks
| | |
Every night the offices download the daily sales,
How many Virutal Circuits will i need on this line, One
All the networks in different locations and times will switch it,
-------------------
What if its modern and u want to install on real time, you would need three virtual circuits
and make them PVC
------------------------------------
-----------------------------------
---------------------------------
X.25 most endeering
Most Reliable protocol ever developed
-Error Handeling
-Flow Control Mechanisms
-----------------------------------
---------------------------------
-------------------------------
-Error Handeling (CRC)
------------------------------
-Max 128 bits
-Closest Circuit does error checking
-EVERY PORT IT'EL DO ERROR CHECKING
------------------------------------
------------------------------------
-FLOW CONTROL
- Any activity that prevents the loss of data
------------------------------------
------------------------------------
X.25 does not drop packets
-flow control mechnisms to stop sending data
--------------------------------------------
Because of speed its not used, ^ the things it does
--------------------------------------------
X.25 perfect for customers Infrequently
X.25 people looking over it!
X.25 1 component of a huge body of work
X.25 RULES PAD EQUIMENT TO ACCESS THE CLOUD
X.25 - small amounts data every so often ==== PERFECT ====
Once in the clout Dozen of protocols you can use
You can attached ur PC to Bells X.25 Network,
Phone connectiong, Packet Sender and Disembler (PAD)100$
--------------------------
X.3 - sepcification for what PADS do
X.75 - International speicification
--------------------------
X.25 is the slang to get into the cloud,
--------------------------
WEEK 13 TEST 2, IN THE LAB we are going to go the quiz, worth 10 %,
2 hours of subnetting
and Access Lists. ACL
GROOVEY LIKE GRAVEY
--------------------------
A packet arrives in a router, and the packet has the address 10.1.240.14, router does not revognize
the address and has the folling mask 255.255.240.0 , company network mask.
Class a 10.1.240.14
00000000.0000|0000.00000000
alL U HAVE TO do to see what subnet it belongs to?
00000001.1111|0000.00000000
subnet 31
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