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
Friday, November 9, 2007
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 ^^
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