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
Monday, November 12, 2007
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
Tuesday, November 6, 2007
OPS435W9
We are going to be covering stuff that is more difficult that what we have done so far,
regular expression, awk, sed language.
Looking at Assignment #2:
A program what makes exchange rate do, take any currency of any country and your program will exchange it to anyother country
from the exchange rate.
Done in 2 stages,
Stage 1, evalaluation varification of input, Nov 16
Stage 2, 2 weeks later
Being Partnersz we are going to use the RCS system
Between the two partners who accounts to use
In that persons home directory ~/asgm2/***/exchange.bash & RCS
710/ 710 / 770/ 770 / 770 /
#GroupMember:
#GroupMember:
The rates are freezed as of today and put on a table on the site
convert.table will reflect the data in that file
cad
CAD
Cad
2arg cad us
Oc can do anything mathimatics
sed -nl | file
We are going to use regular expressions, subject of our lecture today
What are they used for?
To match patterns in data
You can use similar special chars to search for patters in data, called regular expression.
grep 'patt' f1
FNE * - zero or more
RE * - Zero or more of the previous char
FNE . - is dot
RE . - any single char
FNE ? -any single char
RXE ? - is a ? extended regular expression -egrep -awk - zero or one of the previous char
FNE - [!dfds]
RE - [^Fdsa]
RE - ^a[^fds]d - specifies the begining of the line because the other one does any pattern within the line
$ - its the end of the line, this belongs at the end of ^^ that line
.* - zero or more any character, combine those two<---
RE - a\{3\}b - a repeater refereing to the previous char which is a, how many a's their are, 3 a's followed by a b = aaab.
,5 - min 3 max 5, longest pattern first then the shortest
RXE - a+b - extended regular expression - one or more of the previous char. shortest patt ab.
RE - a+b|c?d - the pipe is a or
grep - can use RE - single pattern
egrep - can use RXE - multiple pattern by using the or which is the |
grep 'a+b|c?d' f1 - none are special chars to grep
egrep 'a+b|c?d' f1 - 1 or more a's followed by a b OR zero or 1 c's followed by a d
echo $1|grep '^[0-9]\{8\}$'
(( *sum *= *$?AA *+ *$?BB *))
sed
:S,$ s/exchange/convert/g - in vi
g = globably
no g only first match each line
sed - stream line editor, tell sed what to make to data
sed -op 'address sub-comm/searchpattern/replacepatt/tag' data
some options:
-n
-f
-e
address :
2,10 - only lines through 2 to 10 do the stuff
can also use RE
2,/dog.s/ - start at line 2 next line must have dogs or dogs
/dog.s/,15
1,$ - line 1 to the end of the file
subcommands cover:
s - search
i
a
c
Search pattern:
-RE - here
replacement pattern:
does not use RE
tags:
g - global
d - delete
p
How sed actually really works
has a pattern space buffer,
opens the file takes line number 1 first thing it does check the line number, automatically line 1 goes to STNOUT
Next line comes in #2, address match yes then continue with the rest, if we say s subtitute search for a pattern it will
replace it with that pattern.
sed '/^$/d' f1 - delete blank lines
regular expression, awk, sed language.
Looking at Assignment #2:
A program what makes exchange rate do, take any currency of any country and your program will exchange it to anyother country
from the exchange rate.
Done in 2 stages,
Stage 1, evalaluation varification of input, Nov 16
Stage 2, 2 weeks later
Being Partnersz we are going to use the RCS system
Between the two partners who accounts to use
In that persons home directory ~/asgm2/***/exchange.bash & RCS
710/ 710 / 770/ 770 / 770 /
#GroupMember:
#GroupMember:
The rates are freezed as of today and put on a table on the site
convert.table will reflect the data in that file
cad
CAD
Cad
2arg cad us
Oc can do anything mathimatics
sed -nl | file
We are going to use regular expressions, subject of our lecture today
What are they used for?
To match patterns in data
You can use similar special chars to search for patters in data, called regular expression.
grep 'patt' f1
FNE * - zero or more
RE * - Zero or more of the previous char
FNE . - is dot
RE . - any single char
FNE ? -any single char
RXE ? - is a ? extended regular expression -egrep -awk - zero or one of the previous char
FNE - [!dfds]
RE - [^Fdsa]
RE - ^a[^fds]d - specifies the begining of the line because the other one does any pattern within the line
$ - its the end of the line, this belongs at the end of ^^ that line
.* - zero or more any character, combine those two<---
RE - a\{3\}b - a repeater refereing to the previous char which is a, how many a's their are, 3 a's followed by a b = aaab.
,5 - min 3 max 5, longest pattern first then the shortest
RXE - a+b - extended regular expression - one or more of the previous char. shortest patt ab.
RE - a+b|c?d - the pipe is a or
grep - can use RE - single pattern
egrep - can use RXE - multiple pattern by using the or which is the |
grep 'a+b|c?d' f1 - none are special chars to grep
egrep 'a+b|c?d' f1 - 1 or more a's followed by a b OR zero or 1 c's followed by a d
echo $1|grep '^[0-9]\{8\}$'
(( *sum *= *$?AA *+ *$?BB *))
sed
:S,$ s/exchange/convert/g - in vi
g = globably
no g only first match each line
sed - stream line editor, tell sed what to make to data
sed -op 'address sub-comm/searchpattern/replacepatt/tag' data
some options:
-n
-f
-e
address :
2,10 - only lines through 2 to 10 do the stuff
can also use RE
2,/dog.s/ - start at line 2 next line must have dogs or dogs
/dog.s/,15
1,$ - line 1 to the end of the file
subcommands cover:
s - search
i
a
c
Search pattern:
-RE - here
replacement pattern:
does not use RE
tags:
g - global
d - delete
p
How sed actually really works
has a pattern space buffer,
opens the file takes line number 1 first thing it does check the line number, automatically line 1 goes to STNOUT
Next line comes in #2, address match yes then continue with the rest, if we say s subtitute search for a pattern it will
replace it with that pattern.
sed '/^$/d' f1 - delete blank lines
DCN386 Introduction To SDLC
SDLC Intro-Continue
P=Primary Unit
S=Secondary Unit
-SDLC is a primary Systems Network Architechture (SNA) link layer protocol for WAN links
-Used with PPP & multipoint links bounded & unbounded media, half & full duplex transmission, transmission facilities, and circuit switched and packet switched networks.
- Network nodes: primary and secondary
Primary - control the operation of other station called, secondaries.
P & S connected by four basic configs-
Point-to-Point - two nodes 1P & 1S
Multipoint - 1P 2xS
Loop - topology P = First & Last S (connected to first and last S)
Hub go-ahead - In bound/outbound channel
P-outb-S S-inb-P
In bound daisy-chained back to the P through each S
--------------------------------------------------------------------------------
Derivative Protocols
- IEE 802.2 LLC is a modification of HDLC for LAN enviroments
-HDLC is a compatible super set of SDLC
-Qualified logical link control is a link layer protocol defined by IBM that allows SNA to be transported across X.25 networks.
-----------------------------------------------------------------------------------
High-Level Data Link Control (HDLC)
-HDLC supports sync, full-duplex operation
-HDLC 32-bit checksum, does not support the loop or hub go-ahead configs
SDLC 1 transfer mode
HDLC Supports THREE:
Normal Response Mode (NRM) - Used by SDLC. S cannot communicate with a P until P gives permission
Asynchronous Response Mode (ARM) - S to intiate comm w/ a P unitil P have given permission
Asynchronous balanced Mode (ABM) - Combined mode ABM - act as a P or S depending on the situation - Occurs through multiple combined nodes - No permission required-
----------------------------------------------------------------------------------
Link Access Procedure Balance
- in X.25 protocol stack
- shares same frame types, and field functions as SDLC & HDLC
- Restricted to ABM
- Can be established through DTE & DCE
- Intiate call P responding S
- LAPB use of the P/F bit is different from that of other protocols
-------------------------------------------------------------------------------------
IEEE 802.2
Three types of service
T1- procides unack connectionless service
-TCP/IP componsate for this
-commonly used
T2 -connection oriented
-ack data upon receipt
-used in IBM communication
T3 -ACK service
-Factory automated enviroments
-where eroor detection is important
Upper-layer proccess use IEEE 802.2 services through service access points.
------------------------------------------------------------------------------
802.2 header DSAP - Destination service acc point
- identifies the receiving upper-layer proccesses
------------------------------------------------------------------------------
P=Primary Unit
S=Secondary Unit
-SDLC is a primary Systems Network Architechture (SNA) link layer protocol for WAN links
-Used with PPP & multipoint links bounded & unbounded media, half & full duplex transmission, transmission facilities, and circuit switched and packet switched networks.
- Network nodes: primary and secondary
Primary - control the operation of other station called, secondaries.
P & S connected by four basic configs-
Point-to-Point - two nodes 1P & 1S
Multipoint - 1P 2xS
Loop - topology P = First & Last S (connected to first and last S)
Hub go-ahead - In bound/outbound channel
P-outb-S S-inb-P
In bound daisy-chained back to the P through each S
--------------------------------------------------------------------------------
Derivative Protocols
- IEE 802.2 LLC is a modification of HDLC for LAN enviroments
-HDLC is a compatible super set of SDLC
-Qualified logical link control is a link layer protocol defined by IBM that allows SNA to be transported across X.25 networks.
-----------------------------------------------------------------------------------
High-Level Data Link Control (HDLC)
-HDLC supports sync, full-duplex operation
-HDLC 32-bit checksum, does not support the loop or hub go-ahead configs
SDLC 1 transfer mode
HDLC Supports THREE:
Normal Response Mode (NRM) - Used by SDLC. S cannot communicate with a P until P gives permission
Asynchronous Response Mode (ARM) - S to intiate comm w/ a P unitil P have given permission
Asynchronous balanced Mode (ABM) - Combined mode ABM - act as a P or S depending on the situation - Occurs through multiple combined nodes - No permission required-
----------------------------------------------------------------------------------
Link Access Procedure Balance
- in X.25 protocol stack
- shares same frame types, and field functions as SDLC & HDLC
- Restricted to ABM
- Can be established through DTE & DCE
- Intiate call P responding S
- LAPB use of the P/F bit is different from that of other protocols
-------------------------------------------------------------------------------------
IEEE 802.2
Three types of service
T1- procides unack connectionless service
-TCP/IP componsate for this
-commonly used
T2 -connection oriented
-ack data upon receipt
-used in IBM communication
T3 -ACK service
-Factory automated enviroments
-where eroor detection is important
Upper-layer proccess use IEEE 802.2 services through service access points.
------------------------------------------------------------------------------
802.2 header DSAP - Destination service acc point
- identifies the receiving upper-layer proccesses
------------------------------------------------------------------------------
Monday, November 5, 2007
OPS335W9
OPS335
Lab #7 setting up web server using apache,
Assignment 2 posted
Intresting networking type commands:
netstat -an |grep :80|wc -l - how many connections you have to your apache web server
/sbin/ifconfig - to configure an interface, bring it down or up
Commands located in for:
/sbin - administrators
/bin - regular uses
arp - find out MAC address
hostname - tell you host name or change your host name
host yahoo.com - does a dns query which are handeled on port 53, you can also to ip to hostname
ssh username@hotname - its encrypted
scp - remote:/home/me/junk/* . [from] [to]
rsync - sync two directories, if you have host a and host b with 2 harddrive the firstname you do rsync the two harddrives
because identical to the other harddrive.The second time you do it it copies the files that were updates.
tcpdump - print all traffic in the network - nice to monitor what is going on.
nmap [website] - used for port scan - 65000 on Unix -
wget [website] - retrive website information -r whole website tree
Apache Shell commands
httpd - its a deamon
service httpd restart
The very first webserver was called MOSAIC by NSC government computer before IE before Mozilla.
Apache, pached mosaic, Microsoft Webserver is called IIS
50% =====apache
40% =====IIS
/etc/resolv.conf ----short form of resolver---take a domain name and convert it to an ip number
/etc/hosts - names and ip numbers for the local
/etc/nsswitch.conf - order where to look first
/var/log - contains all logging information, want to know what happen to the system \
rootkit hunter- malacious attack suspected
Assignment
A Man page, and a bash script
mkgw
interneral, masquerading
serveral designes
mkgw.8
volume 8 - fdisk
volume 1 - cat, ls
man man ^^
Lab #7 setting up web server using apache,
Assignment 2 posted
Intresting networking type commands:
netstat -an |grep :80|wc -l - how many connections you have to your apache web server
/sbin/ifconfig - to configure an interface, bring it down or up
Commands located in for:
/sbin - administrators
/bin - regular uses
arp - find out MAC address
hostname - tell you host name or change your host name
host yahoo.com - does a dns query which are handeled on port 53, you can also to ip to hostname
ssh username@hotname - its encrypted
scp - remote:/home/me/junk/* . [from] [to]
rsync - sync two directories, if you have host a and host b with 2 harddrive the firstname you do rsync the two harddrives
because identical to the other harddrive.The second time you do it it copies the files that were updates.
tcpdump - print all traffic in the network - nice to monitor what is going on.
nmap [website] - used for port scan - 65000 on Unix -
wget [website] - retrive website information -r whole website tree
Apache Shell commands
httpd - its a deamon
service httpd restart
The very first webserver was called MOSAIC by NSC government computer before IE before Mozilla.
Apache, pached mosaic, Microsoft Webserver is called IIS
50% =====apache
40% =====IIS
/etc/resolv.conf ----short form of resolver---take a domain name and convert it to an ip number
/etc/hosts - names and ip numbers for the local
/etc/nsswitch.conf - order where to look first
/var/log - contains all logging information, want to know what happen to the system \
rootkit hunter- malacious attack suspected
Assignment
A Man page, and a bash script
mkgw
interneral, masquerading
serveral designes
mkgw.8
volume 8 - fdisk
volume 1 - cat, ls
man man ^^
Saturday, November 3, 2007
DCN386 SDLC RIPv1 compile
SDLC - HDLC - FrameRelay - PPP
SDLC - Synchronous Data Link Control
SDLC - Datalink Protocol which are Point to Point protocols
The Bank and customer start a PPP so their is no Network Layer Involved
Website for SDLC frame and ALL information:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/sdlcetc.htm
Below will Summerize what was talked about in class:
SDLC + HDLC + PPP have one thing in common
Variable Datasize
- the protocol does not specify the maximum data unit
SDLC Fields
Flag |- 8 bits of information - 01111110 -|
The first zero start bit last zero end bit.
Why? - To know when the message is over because its variable datasize
Start and End bits - Marks between data.
To ward off mixed data when the bits have a consecutive 6 1bits SDLC will put an artificial 0 at the end aka bitstuffing.
---------------------------------------------------
Control Field |- 8 bits of informaiton -|
A three bit frame format field: Info Frame, Supervisory Frame, Unnumbered Frame
Info Frame
0 - in the control field, means information is being transmitted
Supervisory Frame
1 - Supervisory frame
- positive ack
- Negative ack
- Flow control Feature
Unnumbered - Used For Network Management Functions
- Shut down & restart "Banke Machines...."
--------------------------------------------------------------------
Still in the control field
|Sequence Number| - 3 bits - Can send 7 frames before an ack is demanaded
000 - Received SN
000 - Send SN
Error checking is done for the seven frames
If they are all correct their will be a supervisory frame of 111 for completeness
----------------------------------------------------------------------
Supervisory Frame
|Function Code| - 00 = means no errors
01 = errors
11 = stop sending data
----------------------------------------------------------------------
Unnumbered Frame - 5 bits -
| function code |
- Bring up down reset
- Done by a Network Manager Person
- Preforms network management functions
----------------------------------------------------------------------
Info | Supervisory | Unnumbered
| Poll Final |
- 1 bit 2 functions
- Depends on direction
We call computers usings these protocols
Central Units & Primary Units
Primary unit - control the ordered delivery of data
Polling will ask each primary unit if it has data
- When it is coming from the final primary unit a final bit is indicated
------------------------------------------------------------------------
Thats it for SDLC at this time.
-------------------------------------------------------------------------
RIPv1 - Request Ip address | Hop Count | Interface ...depending on the Hop count it will choose the lowest one as its main route to destination
- Every 20 seconds a request is made
- Does not address Subnets
-------------------------------------------------------------------------
SDLC - Synchronous Data Link Control
SDLC - Datalink Protocol which are Point to Point protocols
The Bank and customer start a PPP so their is no Network Layer Involved
Website for SDLC frame and ALL information:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/sdlcetc.htm
Below will Summerize what was talked about in class:
SDLC + HDLC + PPP have one thing in common
Variable Datasize
- the protocol does not specify the maximum data unit
SDLC Fields
Flag |- 8 bits of information - 01111110 -|
The first zero start bit last zero end bit.
Why? - To know when the message is over because its variable datasize
Start and End bits - Marks between data.
To ward off mixed data when the bits have a consecutive 6 1bits SDLC will put an artificial 0 at the end aka bitstuffing.
---------------------------------------------------
Control Field |- 8 bits of informaiton -|
A three bit frame format field: Info Frame, Supervisory Frame, Unnumbered Frame
Info Frame
0 - in the control field, means information is being transmitted
Supervisory Frame
1 - Supervisory frame
- positive ack
- Negative ack
- Flow control Feature
Unnumbered - Used For Network Management Functions
- Shut down & restart "Banke Machines...."
--------------------------------------------------------------------
Still in the control field
|Sequence Number| - 3 bits - Can send 7 frames before an ack is demanaded
000 - Received SN
000 - Send SN
Error checking is done for the seven frames
If they are all correct their will be a supervisory frame of 111 for completeness
----------------------------------------------------------------------
Supervisory Frame
|Function Code| - 00 = means no errors
01 = errors
11 = stop sending data
----------------------------------------------------------------------
Unnumbered Frame - 5 bits -
| function code |
- Bring up down reset
- Done by a Network Manager Person
- Preforms network management functions
----------------------------------------------------------------------
Info | Supervisory | Unnumbered
| Poll Final |
- 1 bit 2 functions
- Depends on direction
We call computers usings these protocols
Central Units & Primary Units
Primary unit - control the ordered delivery of data
Polling will ask each primary unit if it has data
- When it is coming from the final primary unit a final bit is indicated
------------------------------------------------------------------------
Thats it for SDLC at this time.
-------------------------------------------------------------------------
RIPv1 - Request Ip address | Hop Count | Interface ...depending on the Hop count it will choose the lowest one as its main route to destination
- Every 20 seconds a request is made
- Does not address Subnets
-------------------------------------------------------------------------
Friday, November 2, 2007
DCN386W9 - SDL HDLC FRAMERELAY RIPv1
Question 1 Test 2
Test 2 in week 13
Scummed the test AAAAAAAAAHHHHHHHHHHHHHHHRRRRRRRRHHHHHHHHHH!
In the course outline
2test each worth 25%,
1Q 10%
FE 40%
Test 1 20%
60/3
Question 1
It’s a protocol
SDLC- Synchronous Data link Control Protocol
For the 100$ coming out of your bank accounts, you use SDLC
IBM’s protocol very expensive
OSI changed SDCL to –HDLC-
HDLC is ciscos default datalink protocol, if you understand SDLC you will understand HDLC
This is a data link layer protocol
IETF renamed it to PPP, is a derivative of HDLC which is the DERATIVE of SDLC
SDLC insights to half a dozen other modern protocols, SDLC and HDLC and PPP and FrameRelay are lay DATALINK layer protocols,
How do you catergorize it, datalink protocols are PPP protocols
What does this mean exactly,
You and to the bank is PPP no Network Layer Involved, by week 14 why is is not a good idea to put a bank machine on the Internet.
You don’t have to worry about Ordered Delivery theirs only one route
It is stressed it is a Data link protocol,
When you want to learn about protocol you look at the control information that is infront TCP/IP 20 bytes of information in front of every protocol.
He will send us a website with the information to the diagram from this lecture
SDLC + HDLC + PPP and all the things have a
Variable data size – the protocol does not specify the maximum data unit
Ethernet is also a data link protocol it has a maximum variable data size.
If you worked at Scotia bank you would pick the maximum data size, it has versatility you can do what you want with the variable size.
U would say if setting up a bank application down at the bottom of the script would be
MAXDATA : 100
The address 8 bits, 2 bytes long
Lets go through this you ask for 100 bucks from a bank machine it will put the information into the data field, the bank machines surrounds your data with this extra information, a 1 byte
FLAG – 8 bit of information - 01111110
Frame Relay same information it starts with a flag
Why do we need flags, know when we know the message is over.
The reason you need a flag cause SDLC does not have a fixed data size,
Ex: what happends a receiving machines gets a start flag it reads data, onlt when it sees an end flag it knows it has received a complete message.
Start flag and end flag are like book marks between the data.
SDLC will guard against theirs another 6 bits that our not ours, when they all want to send a message the protocols will examines the data, looking for an occurrence of six consecutive ones
While building a frame the data is examined if the software (HDLC) if it ever finds 5 consecutive 1 bits it will stick an artificial zero at the end it will say AH I have a astart frame the computer will then remove the artificial bit and restore the bit, this is called BIT stuffing after 5 consecutive 1’s.
The 1’s are used cause we don’t know the size of the data field
The address is manually applied, one thing to consider, a 1 byte control field,
TCP/IP had 20 bytes of control information, very very inefficient, SDLC 8 bits of control information these 8 bits DETERMINE how SDLC operates, To control 8 bits wonderfully efficiently.
All the protocols we we are going to look at have
THREE FRAME formats its determined by the CONTROL FIELD
This is the first format, theirs a 0 in the control field that means an
information frame is being transmitted, however if if its 1 then a 0 then we are dealing with a
supervisory frame – positive ack, neg ack, and flow control feature
We are doing this with 8 bits instead of 20 bytes like TCP
So we got sending data, error handeling done by the supervisory frame,
A THIRD FRAME
Unnumbered – Used for Network Management Functions
its specially special, Network Management software, theirs number frames with 1 command u can take down and put up
SDLC uses what is called a SLIDING WINDOW (this is the window size), they call this a
Sequence Number
000 – Received Sequence Number
000- Send Sequence Numbers
SDLC can send 7 frames before an acknowledgement is demanded
Totally Reliable, it’s a VERY VERY.
Why 7 frames?
001
010
011
It will senevn frames cause the SN only has 7 frames cause it only has 3 bits,
The seven frames will go out into the internet and the deatination computer will get the 7 frames and then it will do
Error Checking
Under 7 frames CRC on each and every frames
If they are all correct the receiving computer will build a supervisory frame in the reciving computer it will put receive data
111
Function Code
00 means no errors
Supervisors address control and flags
The sending machine sends the other information, once it gets to 7 gets back to zero then starts again
What if their was an error in frame 6, it does CRC error checking.
The receiving computer sends a supervisory frame of a function code of 01 indicating their has been an error, 110.
Supervisory from 11 means stop sending data
Supervisory three things, pos ack, neg ack , and flow control
Whether its an information , supervisory and unnumbered frame, why is it unnumbered, cause they have received sequence number
Information have reveinumber send number
Unnumbered have 5 bits of function code, bring a network down up , reset the machine, 5 bits has 32 different functions, Network Manage Person can do function
Understand unnumbered frams perform network management functions.
Supervisory frames never send data, address control and end flag,
You can send data unnumbered frames, buy your RRSP the NMPerson, here’s a little
The final bit
Pull Final – 1 bit has 2 jobs, depends on which direction the message is moving, with SDLC central computer are called primary units and others primary units, primary units are computers that control the ordered delivery of data
Their can be no collisions in SDLC, think about it,
There is two people and they are side by side and they both ask for $100 and press enter at exactly the same time what will happen
POLLING is used for flow control, hence the name POLL, the bank machine handling SDLC each circuit SDLC will send a POLLING message is a supervisory frame with no data the bit in the middle will be turned on,
It will send it to the new frame ask if it has data pull back and see if it needs pulls the data then it goes to the next machine,
POLLING to each machine, pul indicator primary to secondary
Different if its coming from the secondary unit to the primary unit its called a final indicator bit.
Final frame it know it has received 1 2 3 and there is no more frames, 1 bit with 2 jobs.
Next 5 weeks:
WAN protocol, and Internet protocol, Test 2 WAN protocol questions and Internet specific questions
When you typed router rip
Router RIP- To build something called a Routing Information Table
Two flavours of routing information protocols RIP is the oldest.
RIP V2
Configuring router 1, R1 knows two things, R1 knows about subnet 1 and subnet 2,
R2 knows about S2 S3, R3 S3 S4.
RIP starts up in your router, does something intresting, will send out ever interface it knows and every serial it knows
RIP REQUEST – frame of data – 2 pieces of information, it knows about S1 and S2 and will send it to its neighbour, when R2 gets the rip request will send a rip request, it will say it knows about Subnet3 and Router 3
R1
IP address | Hop Count | Interface
S3 1 S0
*Add*
S4 2 S0
Now R1 knows that R1 is associated with R2 subnet 3
R2
IP address | Hop Count | Interface
S1 1 S1
S4 1 S0
Every 20 seconds when started, biggest problem, every 20 seconds on average it sends a RIP request to its Neighbours.
Another 20 seconds pass so R2 will send everything it knows ^^Addings to RIP: router 1 will *Add*
Second Major problem
IETF webpage, - Specification for maximum Hop count of 15
If you connect 2 routers together it will see that it will be 1hop count, rip will always send it out the fasts, the minimum HOP count.
Next week A FAR BETTAH routing PROTOCOL HA HA HA AHHHHH!
OPEN SORTING PATH is by far a superior protocol, far more complex protocol.
When you type in router RIP its rip version rip, the third crucial failure it cannot understand subnets. RIPv2 does address subnets
Test 2 in week 13
Scummed the test AAAAAAAAAHHHHHHHHHHHHHHHRRRRRRRRHHHHHHHHHH!
In the course outline
2test each worth 25%,
1Q 10%
FE 40%
Test 1 20%
60/3
Question 1
It’s a protocol
SDLC- Synchronous Data link Control Protocol
For the 100$ coming out of your bank accounts, you use SDLC
IBM’s protocol very expensive
OSI changed SDCL to –HDLC-
HDLC is ciscos default datalink protocol, if you understand SDLC you will understand HDLC
This is a data link layer protocol
IETF renamed it to PPP, is a derivative of HDLC which is the DERATIVE of SDLC
SDLC insights to half a dozen other modern protocols, SDLC and HDLC and PPP and FrameRelay are lay DATALINK layer protocols,
How do you catergorize it, datalink protocols are PPP protocols
What does this mean exactly,
You and to the bank is PPP no Network Layer Involved, by week 14 why is is not a good idea to put a bank machine on the Internet.
You don’t have to worry about Ordered Delivery theirs only one route
It is stressed it is a Data link protocol,
When you want to learn about protocol you look at the control information that is infront TCP/IP 20 bytes of information in front of every protocol.
He will send us a website with the information to the diagram from this lecture
SDLC + HDLC + PPP and all the things have a
Variable data size – the protocol does not specify the maximum data unit
Ethernet is also a data link protocol it has a maximum variable data size.
If you worked at Scotia bank you would pick the maximum data size, it has versatility you can do what you want with the variable size.
U would say if setting up a bank application down at the bottom of the script would be
MAXDATA : 100
The address 8 bits, 2 bytes long
Lets go through this you ask for 100 bucks from a bank machine it will put the information into the data field, the bank machines surrounds your data with this extra information, a 1 byte
FLAG – 8 bit of information - 01111110
Frame Relay same information it starts with a flag
Why do we need flags, know when we know the message is over.
The reason you need a flag cause SDLC does not have a fixed data size,
Ex: what happends a receiving machines gets a start flag it reads data, onlt when it sees an end flag it knows it has received a complete message.
Start flag and end flag are like book marks between the data.
SDLC will guard against theirs another 6 bits that our not ours, when they all want to send a message the protocols will examines the data, looking for an occurrence of six consecutive ones
While building a frame the data is examined if the software (HDLC) if it ever finds 5 consecutive 1 bits it will stick an artificial zero at the end it will say AH I have a astart frame the computer will then remove the artificial bit and restore the bit, this is called BIT stuffing after 5 consecutive 1’s.
The 1’s are used cause we don’t know the size of the data field
The address is manually applied, one thing to consider, a 1 byte control field,
TCP/IP had 20 bytes of control information, very very inefficient, SDLC 8 bits of control information these 8 bits DETERMINE how SDLC operates, To control 8 bits wonderfully efficiently.
All the protocols we we are going to look at have
THREE FRAME formats its determined by the CONTROL FIELD
This is the first format, theirs a 0 in the control field that means an
information frame is being transmitted, however if if its 1 then a 0 then we are dealing with a
supervisory frame – positive ack, neg ack, and flow control feature
We are doing this with 8 bits instead of 20 bytes like TCP
So we got sending data, error handeling done by the supervisory frame,
A THIRD FRAME
Unnumbered – Used for Network Management Functions
its specially special, Network Management software, theirs number frames with 1 command u can take down and put up
SDLC uses what is called a SLIDING WINDOW (this is the window size), they call this a
Sequence Number
000 – Received Sequence Number
000- Send Sequence Numbers
SDLC can send 7 frames before an acknowledgement is demanded
Totally Reliable, it’s a VERY VERY.
Why 7 frames?
001
010
011
It will senevn frames cause the SN only has 7 frames cause it only has 3 bits,
The seven frames will go out into the internet and the deatination computer will get the 7 frames and then it will do
Error Checking
Under 7 frames CRC on each and every frames
If they are all correct the receiving computer will build a supervisory frame in the reciving computer it will put receive data
111
Function Code
00 means no errors
Supervisors address control and flags
The sending machine sends the other information, once it gets to 7 gets back to zero then starts again
What if their was an error in frame 6, it does CRC error checking.
The receiving computer sends a supervisory frame of a function code of 01 indicating their has been an error, 110.
Supervisory from 11 means stop sending data
Supervisory three things, pos ack, neg ack , and flow control
Whether its an information , supervisory and unnumbered frame, why is it unnumbered, cause they have received sequence number
Information have reveinumber send number
Unnumbered have 5 bits of function code, bring a network down up , reset the machine, 5 bits has 32 different functions, Network Manage Person can do function
Understand unnumbered frams perform network management functions.
Supervisory frames never send data, address control and end flag,
You can send data unnumbered frames, buy your RRSP the NMPerson, here’s a little
The final bit
Pull Final – 1 bit has 2 jobs, depends on which direction the message is moving, with SDLC central computer are called primary units and others primary units, primary units are computers that control the ordered delivery of data
Their can be no collisions in SDLC, think about it,
There is two people and they are side by side and they both ask for $100 and press enter at exactly the same time what will happen
POLLING is used for flow control, hence the name POLL, the bank machine handling SDLC each circuit SDLC will send a POLLING message is a supervisory frame with no data the bit in the middle will be turned on,
It will send it to the new frame ask if it has data pull back and see if it needs pulls the data then it goes to the next machine,
POLLING to each machine, pul indicator primary to secondary
Different if its coming from the secondary unit to the primary unit its called a final indicator bit.
Final frame it know it has received 1 2 3 and there is no more frames, 1 bit with 2 jobs.
Next 5 weeks:
WAN protocol, and Internet protocol, Test 2 WAN protocol questions and Internet specific questions
When you typed router rip
Router RIP- To build something called a Routing Information Table
Two flavours of routing information protocols RIP is the oldest.
RIP V2
Configuring router 1, R1 knows two things, R1 knows about subnet 1 and subnet 2,
R2 knows about S2 S3, R3 S3 S4.
RIP starts up in your router, does something intresting, will send out ever interface it knows and every serial it knows
RIP REQUEST – frame of data – 2 pieces of information, it knows about S1 and S2 and will send it to its neighbour, when R2 gets the rip request will send a rip request, it will say it knows about Subnet3 and Router 3
R1
IP address | Hop Count | Interface
S3 1 S0
*Add*
S4 2 S0
Now R1 knows that R1 is associated with R2 subnet 3
R2
IP address | Hop Count | Interface
S1 1 S1
S4 1 S0
Every 20 seconds when started, biggest problem, every 20 seconds on average it sends a RIP request to its Neighbours.
Another 20 seconds pass so R2 will send everything it knows ^^Addings to RIP: router 1 will *Add*
Second Major problem
IETF webpage, - Specification for maximum Hop count of 15
If you connect 2 routers together it will see that it will be 1hop count, rip will always send it out the fasts, the minimum HOP count.
Next week A FAR BETTAH routing PROTOCOL HA HA HA AHHHHH!
OPEN SORTING PATH is by far a superior protocol, far more complex protocol.
When you type in router RIP its rip version rip, the third crucial failure it cannot understand subnets. RIPv2 does address subnets
Subscribe to:
Posts (Atom)