Download - CCNA at a glance
CCNA at a glance
CISCO 60%40%
D-Link
3 Com
Nortel
Cygnus
Etc..
Cisco’s Market Share
Router is an internetworking component, that connects networks which are at different geographical
locations.
Serial 1 Serial 0 AUIE 0
Console
V.35 modem
modem
Telephone
PC
AUX
Diagram of 2501 series Router
Interfaces on a Router
1. Ethernet It is a LAN interface. Some of the models have an RJ45 port for 10baseT or 10/100. And some other
have a 15 pin female connector AUI (Attachment Unit Interface).
2. Serial It is a 60 pin female WAN interface for leased line
3. BRI/PRI It is a RJ45 WAN interface for ISDN
4. Async It is a 37 pin female connector for dial ups.
5. Console It is a RJ45 Connector used to configure the Router for the first time.
6. Auxiliary RJ45 Connector for remote access administration.
Routers
Modular Fixed
Modular Routers
These type of routers have up gradable slots, and the number of ports can be increased just by adding cards in the slots.
Fixed Routers
These types of routers have fixed number of ports.
Cisco Router’s Series
Cisco 700, 800, 1600, 1700, 2500, 2600, 3600, 4000, 5000, 7000,10000, 12000.
Fixed Modular
700, 800,….2500 2600,….., 12000
1750 & 1751 exceptionally are Modular Routers.
Cisco’s Hierarchical Model
Access Layer
700, …, 2500
Distribution Layer
2600, …, 5000
Core Layer
7000, …, 12000
Transceiver
Internal Components of a Router
Boot ROM : It stores the mini IOS (Internet work Operating System) image (RX Boot) with extremely limited capabilities and POST routines and core level OS for maintenance.
FLASH : It is an EPROM chip that holds most of the IOS Image. It maintains everything when router is turned off.
RAM : RAM holds running IOS configurations and provides caching. RAM is a volatile memory and looses its information when router is turned off. The configuration present in RAM is called Running configuration.
NVRAM : It is a re-write able memory area that holds router’s configuration file. NVRAM retains the information when ever router is rebooted. Once configuration is saved, it will be saved in NVRAM and this configuration is called Startup Configuration.
Configuration of a Router Router for the first time is configured through the CONSOLE
port.COM port of a PC is connected to the console port of router with a console cable by using a transceiver. Router is accessible by a tool. In windows, it is called HYPER TEMINAL. As soon as the router is powered on and accessed, the following things happen,
POST
BOOT STRAP
FLASH
NVRAM
Setup Mode
ROM (mini IOS)If IOS is Corrupted
In Setup mode, there will be a message,
“Would You Like To Enter The Initial Configuration [Y/N]” :
If “Y” then, initial configuration starts.
If “N” would you like to terminate the auto installation?
Press “RETURN” to get started……You will land on the default prompt of the Router “ ROUTER >”.
Router>_
Working Modes Of a Router
1. User Mode (Default mode)
2. Privilege or Administrative Mode
3. Global Configuration Mode
4. Interface Configuration Mode
5. Line Configuration Mode
6. Router Mode
7. Sub-Interface Mode
USER MODE
Router> is the user mode, I,e the default prompt. It means that when ever a router boots successfully it lands into the user mode. Router cannot be configured from this mode, but it is used for just monitoring purpose. Router> en
Router #
PREVILEGE MODE
Router# it is the administrating mode, we can check whether the settings and configurations made have been implemented or not. Eg. “Router # Sh int e0”. If it is new router all the interfaces are by default shut down, so the message will be, “ Ethernet 0 is administratively down, line protocol is down.”
Router# Config t
Router (Config)#
Global Configuration Mode
As the name indicates, it is a global configuration mode I,e. we can configure any interface from this mode, just by entering into the interface mode.
The “Clock” Command
The clock command is used to set the clock of Router.
Syntax.
Router# clock set hh:mm:ss Day of week Month Year
E.g.
Router#clock set 16:35:00 1 April 2003
Note* This is the only configuration which can be done from privilege mode,every other configuration should be done at global configuration mode only.
Some of the important show commands in privilege mode
Router# sh clocksh int (interface name eg e0)Sh historySh memorySh running-config
Sh startup-config
To save configuration from RAM TO NVRAM
Router#Copy Running-config Startup-config (or)
Router#Write Memory
To configure Hostname (or) Identification of Router over the network.
Router#conf t
Router(config)#Hostname R_2503
Router(config)#^Z
To configure Logging banner.
Router#conf t
Router(config)#Banner Motd #
Enter text message………….#
Router(config)#^Z
Router Password Configuration
1. Previlege Password
2. Virtual Terminal Password
3. Console Password
4. Auxillary Password
Previlege PASSWORDS
Enable Password Enable Secret
Enable Password:- It is global command restricts access to the previlege mode, the password is in clear text.
Router(config)#Enable password 123
Enable Secret:-Here the password is in encrypted form.
Router(config)#Enable secret cisco
Virtual Terminal Password
It establishes a login password on incoming Telnet sessions. Router#conf t
Router(config)#Line vty 0 4
Router(config-line)#Login
Router(config-line)#password cisco
Router(config-line)#^Z
Console Password
It establishes a login password on the console terminal.
Router#conf t
Router(config)#Line Console 0
Router(config-line)#Login
Router(config-line)#Password cisco
Router(config-line)#^Z
Auxillary Password
It establishes a login password to remote administration.
Router#conf t
Router(config)#Line Aux 0
Router(config-line)#Login
Router(config-line)#Password cisco
Router(config-line)#^Z
CONFIGURING INTERFACES
LAN interface (ETHERNET Port)
WAN interface (SERIAL Port)
ETHERNET
Router(config)#Interface Ethernet 0
Router(config-if)#Ip Address 200.150.1.254 255.255.255.0
Router(config-if)#no shutdown
Router(config-if)#^Z
Router#Show Int E0
SERIAL
Router(config)#Interface Serial 0
Router(config-if)#Ip Address 150.10.1.1 255.255.0.0Router(config)#clock rate 56000Router(Config-if)# bandwidth 64Router(config-if)#No shutdown
Router(config-if)#^Z
Interpretring The Interface Status
Router# show int s0
Serial0 is up, line protocol is up. Is the messege if the interface is operational.
Serial0 is up, line protocol is down….. This is if there is any connection problem.
Serial0 is down, line protocol is down….. This is if there is any interface problem.
Serial0 is administratively down, line protocol is down….. This is if the interface is disabled.
The “CDP”It’s a Cisco's proprietary protocol called the Cisco Discovery Protocol, that gives you a summary of all the directly connected Cisco devices. CDP is a L2 protocol, that discovers neighbor regardless of which protocol suite they are running. When a cisco device boots up, the CDP is loaded by default, but can be disabled at interface level.
* The CDP is limited to the immediate neighbors only…
The summary includes Device Identifier(eg. Switch configured name or domain name), Port Identifier (eg. Ethernet 0 and serial 0.), Capabilities list (eg. The device can act as a sourcr route bridge as well as a router), Platform (eg. Cisco 2600).
CDP (Cisco’s Discovery Protocol)
Using CDP
Router# sh cdp neighbor (shows neighboring devices)
To disable CDP….,
Router(config)#no cdp runRouter(config)#int s0Router(config-if)#no cdp enable
Router# sh cdp entry 192.168.10.1 (shows detailed information about this perticular neighbor.)
Router# sh cdp interface(shows the details of the interface of the local decive.)Router# sh cdp traffic (shows the packet sent, received, lost etc.)
Backup & Restoring Routers IOS Image
Using TFTP
(Trivial File Transfer Protocol)
TFTP Server allows you to take backup, upload and save your IOS Image and current configuration on it. TFTP is a software program of 1.3Mb. This should be installed on that TFTP server i.e., (Personnel Computer).
C:\Program files\cisco systems\cisco TFTP
* Note: Always while taking Backup or Restoration TFTP software should execute on that particular computer.
Backup Sources :
1. Through Telnet Session.
2. Through Console Session.
3. Through Auxillary Port (Remote Session)
Backup of IOS Image
Router#Copy Flash:(Press Tab key) Tftp
Address or name of the remote host [ ]? (Ip address of tftp)
Destination file name [ ] ? (Press enter key or a name)
Backup of Configuration
Router#Copy Startup-config Tftp
Address or name of the remote host [ ]? (Ip address of tftp)
Destination file name [ ] ? (Give a name)
Upgrading IOS ImageNote: This process can only be done by Console Session.
Router#Copy tftp Flash:Address or name of remote host []?
Source file name []?
Destination file name []?
Erase Flash: before copying [confirm]?
Erasing the Flash file system will remove all files: continue? [confirm]
Erasing device eeeeeeee……….eeeeeee.eee.eeee.ee
Loading!!!!!!!!!!!!!!!!!!!!!!!!!!!!!…….!!!!…….!!!!!!
Leased line WAN Setup
Case 1: The distance between the locations is greater than 5 Km.
Requirements
A pair of Routers, Leased line, pair of leased line modems V.35,
Pair of G.703 Modem.
Case 2: The distance between the two locations is less than 5Km.
Requirements
A pair of Routers, Leased line and pair of leased line modem.
Internal Network Internal Network
V.35 Cable
Csu/Dsu
Switch/hub
V.35 modem
Csu – channel service unitDsu – data service unitS0 – Serial port of routerE0 – Ethernet port of a router
G.703 G.703
Mux/Dmux
Mux/DmuxS0
E0S0
E0
Switch/hubRouter
V.35 modem
Leased line Setup( > 5km)
Leased line
Leased line Setup (< 5 km)
Internal Network Internal Network
V.35 Cable Csu/Dsu
Switch/hub
V.35 modem
S0
E0 S0 E0
Switch/hubRouter
V.35 modem
Leased line
Telephone
Exchange
RoutingRouting is of three types.
• Static
• Dynamic and
• Default
When the destination is known, static and dynamic routing is done. For unknown destinations, default routing is employed.
In dynamic routing, the path is fixed by the protocol. The paths will be changing depending on the length of the path. Always the shortest path is preferred. Static routing is done by the users. These paths are stored in the routing table.
Example:
Switch/hub Switch/hub
E 0 E 0
S 0S 0
192.168.1.0/24 192.168.2.0/24
192.168.1.150/24 192.168.2.150/24
10.0.0.1/8 10.0.0.2/8
Location A Location B
Router(config)# ip routing
Router# sh ip route (it shows all the directly connected networks).
“ C 192.168.1.0/24 directly connected to E0”
“ C 10.0.0.0/8 “ ‘ ‘ ‘ S0”
“ C “ indicates connected networks.
Static Routing
Syntax
Router(config)# ip route (dest-network) (subnet mask) (next hop address)
Location A
Router(config)# ip routing
Router(config)# ip route 192.168.2.0 255.255.255.0 10.0.0.2
Note* if we don’t know the address of next hop, we can just write the name of the hop.
Router(config)# ip route 192.168.2.0 255.255.255.0 S0
Location B
Router(config)# ip routing
Router(config)# ip route 192.168.1.0 255.255.255.0 10.0.0.1
Router# sh ip route
C 192.168.1.0/24 directly connected to E0
C 10.0.0.0/8 “ ‘ “ “ S0
S 192.168.2.0/24 [1/0] via 10.0.0.2
• “S” represents static. [a/b] ~ [1/0], here a=1 is the administrative distance value and b has no significance in static routing. For static and default routing b can be 0 or 1.
• lesser the administrative distance value, higher the preference.
“Tracert”, “Trace Route” and “Route print”.
C:\> tracert
C:\> route print
Router# trace route (gives the complete route)
Router# sh arp (to check MAC addresses)
Default RoutingRouter(config)# ip routing
Router(config)#ip route DA (S/N mask next) (next hop address)
Router(config)# ip route 0.0.0.0 0.0.0.0 s1
Router# sh ip route
C 192.168.1.0/24 directly connected to E0
C 10.0.0.0/8 “ “ to S0
S* 0.0.0.0/0 “ “ to S0
Dynamic RoutingIt is a type of routing where routing protocols( eg. RIP and IGRP) are used between routers to determine the path and maintain routing table. Once the path is determined a router can route a routed protocol(IP). Dynamic routing uses broad casts and multicasts to communicate with other routers. The routing metric helps routers find the best path to each network.
Classification Of Routing Protocols Distance Vector
Hybrid Routing
Link State
Distance Vector: the distance vector approach determines the direction and the distance to any link in the internetwork. When the topology in a distance vector routing protocol changes, routing table updates in the router must occur. This update process proceeds step-by-step router to router. Eg. RIP and IGRP.
Link State : it recreates the exact topology of the entire network(atleast the partion of the network where the router is situated). Eg . OSPF.
Functions of a distance vector routing protocol.
Identification of source of information
Discovering routes
Select the best route
Maintain Route information
Hybrid Routing : it combines aspects of the link state and the distance vector algorithm.
Note:
• Maximum 6 paths (Default 4).
• “Hop count metric” selects the path
• Route updates are broadcast for every 30 seconds.
Router(config)# router rip
Router(config-router)# network (network ip)
Enabling RIP Configuration
Router# sh ip protocol (shows the current routing protocol)
Router# sh ip route
172.16.1.0
E0 S2 S2 S3 S3 E0
192.168.1.0
172.16.1.1
10.1.1.1
10.1.1.2
10.2.2.2
10.2.2.3192.168.1.1
Router rip
Network 172.16.0.0
Network 10.0.0.0
Router rip
Network 10.0.0.0 Router rip
Network 192.168.1.0
Network 10.0.0.0
Autonomous Systems
An autonomous system is a collection of networks under a common administrative domain. IGPs operate within an autonomous system where as EGP connects different autonomous systems.
Every autonomous system has a distinct number.The Internet Assigned Numbers Authority (IANA) is responsible for allocating this number. Eg. Autonomous system 100.
We can use any number unless the organization plans for an EGP.
Configuring IGRPSyntaxes.
Router(config)#router igrp autonomous number
This defines IGRP as the routing protocol.
Router(config-router)#Network network-ip
Selects directly connected networks.
Router(config-router)#variance multiplier
Configures unequal-cost load balancing by defining difference between the best metric and the worst acceptable metric.
Router(config-router)#traffic-share (balanced/ min)
Autonomous System 100172.16.1.0
E0 S2 S2 S3 S3 E0
192.168.1.0
172.16.1.1
10.1.1.1
10.1.1.2
10.2.2.2
10.2.2.3192.168.1.1
Router igrp 100
Network 172.16.0.0
Network 10.0.0.0
Router igrp 100
Network 10.0.0.0 Router igrp 100
Network 192.168.1.0
Network 10.0.0.0
IP Classless CommandRouter(config)# ip classless
A router by default assumes that all the subnets of a directly connected network should be present in the routing table. If a packet is received with a destination address, of an unknown subnet of directly attached network, the router assumes that the subnet does not exists and drops the packet. This happens even if routing table has a default route.For the above condition if IP Classless is configured, and if any packet is received, then the router will match it to the default route and forword it to the next hop specified by the default route.
EIGRP
Calculation of Wildcard MaskWCM = BCM-SNM
1. 192.168.1.0/24
255.255.255.255
- 255.255.255. 0
0 . 0 . 0 .255
2. 192.168.1.0/27
255.255.255.255
- 255.255.255.224
0 . 0 . 0 . 31
3. 192.160.1.10 0.0.0.0
OSPF
OSPF(Open Short Path First) is of two types : 1) Single Area OSPF and2) Multi Area OSPF.
Internal Routers
Area1
Area2
Area Border RouterIR
IR
ABR
ABR
Area0S 0
S 0
Router A Router B
S 0 192.168.1.194/252 192.168.1.193/252 S 0
E 0 1.65
192.168.1.32/255.255.255.224
192.168.1.64/255.255.255.224
E 0 1.33
OSPF under Single Area
(Config)# ip routing(Config-Router)# router OSPF 6573(Config-Router)# network 192.168.1.32 0.0.0.31 area 1(Config-Router)# area 1 range 192.168.1.32 255.255.255.224(Config-Router)# network 192.168.1.192 0.0.0.3 area 1(Config-Router)# area 1 range 192.168.1.192 255.255.255.224
(Config)# ip routing(Config-Router)# router OSPF 6573(Config-Router)# network 192.168.1.32 0.0.0.31 area 1(Config-Router)# area 1 range 192.168.1.64 255.255.255.224(Config-Router)# network 192.168.1.195 0.0.0.3 area 1(Config-Router)# area 1 range 192.168.1.195 255.255.255.252
Configuration of Router B--------------------------------
OSPF under Different Areas
Area 0
192.168.1.0 192.168.5.0
Area 1 Area 2
E0 E0
5.50
Router A Router B
1.50
(Config)# ip routing(Config-Router)# router OSPF 6573(Config-Router)# network 192.168.1.0 0.0.0.255 area 1(Config-Router)# area 1 range 192.168.1.0 255.255.255.0(Config-Router)# network 172.16.0.0 0.0.255.255 area 0(Config-Router)# area 0 range 172.16.0.0 255.255.0.0
Configuration of Router A--------------------------------
Configuration of Router B--------------------------------
(Config)# ip routing(Config-Router)# router OSPF 6573(Config-Router)# network 192.168.5.0 0.0.0.255 area 2(Config-Router)# area 2 range 192.168.5.0 255.255.255.0(Config-Router)# network 172.16.0.0 0.0.255.255 area 0(Config-Router)# area 0 range 172.16.0.0 255.255.0.0
Access Control ListIt is also called Network Traffic Control
Management (NTCM). We can provide restrictions to individual users, subnets and services etc.
ACL
Standard ACL Extended ACL
Any access list is identified by its number.
S. A. L 1 – 99
Ex. A. L 100 - 199
Rules for creating and implementing Access List
1. Access list must begin with the Deny Statements (If exists) then Permit Statements must follow.
2. There must be at least one Permit Statement as an Implicit “Deny All” always exists.
3. While Implementation of Access list, There must be only one Access list per Interface, per direction and per protocol.
Standard Access List
Router A Router B
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.21.3
1.45.1
5.2
5.4
5.3
E 0 1.50
Syntax
Router(config)# Access-list ALNO P/D Src Src-WCM
Router(config)# Int <name of interface>
Router(Config-if)#Ip Access-Group <Direction>
Configuration Standard Access-list For Router A
Restricting particular user(Config)# Access-list 1 deny 192.168.1.3 0.0.0.0(Config)# Access-list 1 permit 0.0.0.0 255.255.255.255 or
Access-list 1 permit anyRestricting a Network(Config)# Access-list 1 deny 192.168.3.0 0.0.0.255(Config)# Access-list 1 permit any
Extended Access List
Router A Router B
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.21.3
1.4 5.1
5.2
5.4
5.3
E 0 1.50
1.20
Configuration of Router A
(Config)# Access-list 101 deny TCP 192.168.5.0 0.0.0.255 192.168.1.20 0.0.0.0 eq FTP
(Config)# Access-list 101 permit IP any any
Implementation
(Config)#int E0
(config-if)# IP Access-group 101 Out
NAT(Network Address Translation)
Router A Router B
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.2192.168.1.3
1.4 5.1
5.2
5.4
5.3
E 0 1.50
Note : 192.168.1.3 is denied from entering the network of 5.0.So it will enter with mask.
Configuration of Router A --------------------------------
# Config t(Config)# int E 0(Config-if)# ip address 192.168.1.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.1 255.255.0.0(Config-if)# clock rate 56000(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config-Router)# ip route 192.168.5.0 255.255.255.0 172.16.1.2
(Config)# int E 0(Config-if)# ip nat inside
(Config)# int S 0(Config-if)# ip nat outside
(Config)# access-list 1 permit 192.168.1.3 0.0.0.0(Config)# ip nat inside source list 1 int S 0 overload
# Config t(Config)# int E 0(Config-if)# ip address 192.168.5.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.2 255.255.0.0(Config-if)# clock rate 56000(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
Configuration of Router B --------------------------------
(Config)# ip routing(Config-Router)# ip route 192.168.1.0 255.255.255.0 172.16.1.1
(Config)# access-list 10 deny 192.168.1.3 0.0.0.0(Config)# access-list 10 permit any
(Config)# int E 0(Config-if)# ip access-group 10 out
Note : Only Public IP can go to the Internetworking world.
A Scenario of providing Net access to the IP's of Router B
Natting
Router A Router B
Switch
Routing
Leased line
Routing5.05.501.50
172.16.1.1 172.16.1.2
192.168.1.99
Configuration of Router A --------------------------------
# Config t(Config)# int E 0(Config-if)# ip address 192.168.1.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.1 255.255.0.0(Config-if)# clock rate 56000(for DCE)(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config-Router)# ip route 0.0.0.0 0.0.0.0 192.168.1.99
(Config)# int S 0(Config-if)# ip nat inside((Config-if)# exit
(Config)# access-list 10 permit 172.16.0.0 0.0.255.255(Config)# ip nat inside source list 10 int E 0 overload
(Config)# int E 0(Config-if)# ip nat outside(Config-if)# no shut(Config-if)# exit
Configuration of Router B --------------------------------# Config t(Config)# int E 0(Config-if)# ip address 192.168.5.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.2 255.255.0.0(Config-if)# clock rate 56000(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
(Config)# int E 0(Config-if)# ip nat inside(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip nat outside(Config-if)# exit
(Config)# ip routing(Config-Router)# ip route 0.0.0.0 0.0.0.0 172.16.1.1
(Config)# access-list 10 permit 192.168.5.0 0.0.0.255(Config)# ip nat inside source list 10 int E 0 overload
PPP(Point-to-Point) using PAP protocol
Router A(ISDN)
Router B(Zoom)
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.21.3
1.4 5.1
5.2
5.4
5.3
E 0 1.50
Internet based leased line
NOTE : Passwords of both should be same.
Configuration of Router A --------------------------------# Config t(Config)# int E 0(Config-if)# ip address 192.168.1.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.1 255.255.0.0(Config-if)# clock rate 56000(for DCE)(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config-Router)# ip route 192.168.5.0 255.255.255.0 172.16.1.2
(Config)# int S 0(Config-if)# encapsulation ppp(Config-if)# ppp authentication PAP(Config-if)# ppp PAP sent-username zoom password cisco
Configuration of Router B --------------------------------# Config t(Config)# int E 0(Config-if)# ip address 192.168.5.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.2 255.255.0.0(Config-if)# clock rate 56000(for DCE)(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config-Router)# ip route 192.168.1.0 255.255.255.0 172.16.1.1
(Config)# int S 0(Config-if)# encapsulation ppp(Config-if)# ppp authentication PAP(Config-if)# ppp PAP sent-username ISP password cisco
PPP(Point-to-Point) using CHAP protocol
Router A(ISDN)
Router B(Zoom)
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.21.3
1.4 5.1
5.2
5.4
5.3
E 0 1.50
Internet based leased line
NOTE : Passwords of both should be same.
Configuration of Router A --------------------------------# Config t(Config)# int E 0(Config-if)# ip address 192.168.1.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.1 255.255.0.0(Config-if)# clock rate 56000(for DCE)(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config-Router)# ip route 192.168.5.0 255.255.255.0 172.16.1.2
(Config)# int S 0(Config-if)# encapsulation ppp(Config-if)# ppp authentication CHAP(Config-if)# ppp CHAP hostname zoom (Config-if)# ppp CHAP password cisco
Configuration of Router B --------------------------------# Config t(Config)# int E 0(Config-if)# ip address 192.168.5.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.2 255.255.0.0(Config-if)# clock rate 56000(for DCE)(Config-if)# bandwidth 64(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config-Router)# ip route 192.168.1.0 255.255.255.0 172.16.1.1
(Config)# int S 0(Config-if)# encapsulation ppp(Config-if)# ppp authentication CHAP(Config-if)# ppp CHAP hostname ISP(Config-if)# ppp CHAP password cisco
DDR(Dial on Demand Routing)
Router A Router B
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.21.3
1.4 5.1
5.2
5.4
5.3
E 0 1.50
ISP
# Config t(Config)# isdn switch-type basic-net 3
(Config)# int E 0/1(Config-if)# ip address 192.168.1.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int Bri 1/0(Config-if)# no ip address(Config-if)# encapsulation ppp(Config-if)# no cdp enable(Config-if)# no shut(Config-if)# exit
(Config)# int dialer 1(Config-if)# ip address negotiated(Config-if)# encapsulation ppp(Config-if)# no cdp enable(Config-if)# ppp authentication CHAP PAP callin(Config-if)# ppp CHAP hostname unicomin@hd2(Config-if)# ppp CHAP password password
(Config-if)# ppp PAP sent-username unicomin@hd2 password password(Config-if)# dialer in-band (Config-if)# dialer string 3328400(Config-if)# dialer idle-time out 180(Config-if)# dialer hold-queue 10(Config-if)# exit
(Config)# access-list 1 permit 192.168.1.0 0.0.0.255(Config)# dialer-list 1 protocol ip permit
((Config)# int bri 1/0(Config-if)# dialer rotary-group 1(Config-if)# no shut(Config-if)# exit
(Config)# int dialer 1(Config-if)# dialer-group 1(Config-if)# exit
(Config)# ip routing(Config-router)# ip route 0.0.0.0 0.0.0.0 dialer 1 2
(Config)# ip name-server 202.54.30.2(Config)# ip name-server 202.54.2.30
(Config)# int E 0(Config-if)# ip nat inside(Config-if)# no shut(Config-if)# exit
(Config)# int Bri 1/0(Config-if)# ip nat outside(Config-if)# no shut(Config-if)# exit
(Config)# int dialer 1(Config-if)# ip nat outside(Config-if)# exit
(Config)# ip nat inside source list 1 int dialer 1 overload
Backup Interface for a Leased Line
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.21.3
1.4 5.1
5.2
5.4
5.3
E 0 1.50
ISP
ISP
CPE -Customer Premises Equipment
DTE -Data Communications & Circutary end
CPE/DTEBri 0
# Config t(Config)# isdn switch-type basic-net 3
(Config)# int E 0/1(Config-if)# ip address 192.168.1.50 255.255.255.0(Config-if)# no shut(Config-if)# exit
(Config)# int S 0(Config-if)# ip address 172.16.1.1 255.255.0.0
(Config)# int Bri 1/ 0(Config-if)# no ip address(Config-if)# encapsulation ppp(Config-if)# no cdp enable(Config-if)# no shut(Config-if)# exit
(Config)# int dialer 1(Config-if)# ip address negotiated(Config-if)# encapsulation ppp(Config-if)# no cdp enable(Config-if)# ppp authentication CHAP PAP callin(Config-if)# ppp CHAP hostname zoom(Config-if)# ppp CHAP password cisco(Config-if)# ppp PAP sent-username isp password cisco(Config-if)# dialer in-band (Config-if)# dialer string 3328400(Config-if)# dialer ideal-time out 180(Config-if)# dialer hold-queue 10(Config-if)# exit
(Config)# access-list 1 permit 192.168.1.0 0.0.0.255(Config)# dialer-list 1 protocol ip permit
((Config)# int bri 1/ 0(Config-if)# dialer rotary-group 1(Config-if)# no shut(Config-if)# exit
(Config)# int dialer 1(Config-if)# dialer-group 1(Config-if)# exit
(Config)# ip routing(Config-router)# ip route 0.0.0.0 0.0.0.0 S 0(Config-router)# ip route 0.0.0.0 0.0.0.0 dialer 1 2
(Config)# ip name-server 202.54.30.1(Config)# ip name-server 202.54.1.30
(Config)# int E 0(Config-if)# ip nat inside(Config-if)# no shut(Config-if)# exit
(Config)# int Bri 1/ 0(Config-if)# ip nat outside(Config-if)# no shut(Config-if)# exit
(Config)# int dialer 1(Config-if)# ip nat outside(Config-if)# exit
(Config)# Access-list 2 permit 4 public 10(Config)# ip nat inside source list 2 int dialer 1 overload
(Config)# int S 0(Config-if)# backup interface bri 1/0(Config-if)# backup delay 30 60
Frame Relay
Point - to - Pointframe-relay Network
Router A
S 0 172.16.1.1 172.16.1.2 S 0
E 0 5.50
1.1
1.21.3
1.4 5.1
5.2
5.4
5.3
E 0 1.50
Dlci 101 Dlci 102 Router B
Fr-Switch Fr-Switch
PVC
Config t(Config)# int S 0(Config-if)# no ip address(Config-if)# encapsulation frame-relay(Config-if)# no shut(Config-if)# exit
(Config)# int S 0.1 point-to-point(Config-if)# bandwidth 64(Config-if)# ip address 172.16.1.1 255.255.0.0(Config-if)# frame-relay interface DLC1 102 (or)(Config-if)# frame-relay map ip 172.16.1.2 102 broadcast(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config)# ip route 192.168.5.0 255.255.255.0 172.16.1.2
Point - to - Multi Point
10.0.0.4
101
102
A
B
C
D
103
104
10.0.0.3
10.0.0.2
10.0.0.14.0
2.0
3.01.0
Config t(Config)# int S 0(Config-if)# no ip address(Config-if)# encapsulation frame-relay(Config-if)# no shut(Config-if)# exit
(Config)# int S 0.1 multipoint(Config-if)# bandwidth 64(Config-if)# ip address 10.0.0.4 255.0.0.0(Config-if)# frame-relay map ip 10.0.0.1 103 broadcast(Config-if)# frame-relay map ip 10.0.0.2 102 broadcast(Config-if)# frame-relay map ip 10.0.0.3 101 broadcast(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config)# ip route 192.168.2.0 255.255.255.0 10.0.0.3(Config)# ip route 192.168.4.0 255.255.255.0 10.0.0.1(Config)# ip route 192.168.5.0 255.255.255.0 10.0.0.2
Configuration of Router A --------------------------------
Point-to-Point - Point-to-Point
4.0
2.0
3.01.0
10.0.0.1
10.0.0.3
10.0.0.2
172.16.1.2
172.16.1.1
161.16.1.1
101
102
103
104
Config t(Config)# int S 0(Config-if)# no ip address(Config-if)# encapsulation frame-relay(Config-if)# no shut(Config-if)# exit
(Config)# int S 0.1 point-to-point(Config-if)# bandwidth 64(Config-if)# clockrate 56000(Config-if)# ip address 172.16.1.1 255.255.0.0(Config-if)# frame-relay map ip 172.16.1.2 103 broadcast(Config-if)# no shut(Config-if)# exit
Configuration of Router A --------------------------------
(Config)# int S 0.2 point-to-point(Config-if)# ip address 161.16.1.1 255.255.0.0(Config-if)# no shut
(Config-if)# bandwidth 64(Config-if)# clock rate 56000(Config-if)# frame-relay map ip 161.16.1.2 102 broadcast(Config-if)# exit
(Config)# int S 0.3 point-to-point(Config-if)# bandwidth 64(Config-if)# clockrate 56000(Config-if)# ip address 10.0.0.1 255.0.0.0(Config-if)# frame-relay map ip 10.0.0.2 101 broadcast(Config-if)# no shut(Config-if)# exit
(Config)# ip routing(Config)# ip route 172.16.0.0 255.255.0.0
IsoInternational organization for standardizationIso has designed a reference model called osi reference model (open system interconnection). It has 7 layers. It says that Any n/w for comunication needs 7 layers1. Application layerThe user uses application layer to send the data. The protocols@ this layer are ftp,http,smtp(e-mail) telenet etc.2. Presentation layerPresentation layer takes the data from application layer and presentIn different formats for securing reason. The services offered @This layer areCompression – decompressionCoding – decodingEncryption - decryption
3. Session layerEstablishing the session or the conectivity n/w n/w 1 & n/w 2 is doneBy the session layer.It 1. Establishes a session
2. maintains it &3. Terminates it b/w the application
4. Transport layerEnd-end connectivity during a session b/w two application is doneBy the transport layer. It also decides the type of connection like tcp or udp i.e. connection oriented or connection less.Services:SequencingFlow ctrl, error detection & correctionTransport layer info + data is called segment.
5. Netwrok layerLogical addressing is done at thenetwork layer i.e. source address &destination address are attached to the data.
Protocols @network layer
Routed protocols routing protocolsEg: ip,ipx eg: rip,igrp,ospf
Routed protocols: they always carry the data along with themRouting protocol: they identify the path for routed protocol to carry the dataAt this layer routers & layer 3 switches forms packets.
Data link layer
MAC LLCMedia access control logical link control framing of data
Ip address is lik the pincode & MAC address is like house number.Here layer2 switches are used.Wab protocols used at this layer are PPP,HDLC,FP,X.25 etc.Here error checking CRC bits are added to the packetsDLL info+ packets --> frames
7 physical layerTakes care of physical connectivity i.e connector,cable etc. hereFrames are converted to bits (1’s & 0’s).The devices like hubs, repeaters,cables & connectors are used at this layer.
I P Addressing Now a days ip ver4 is followed. It is a 32-bit addressing scheme. 32bits are divided into 4 octets of 8 bits each.i.e 8-8-8-8. i.e (1’s & 0’s)-(1’s & 0s)-(1’s & 0’s)-(1’s & 0’s).(binary format). The ip address is maximum of 255 & min of 0.In future ip ver 6 is expected. It is 128 bit scheme.Ip adresses are clsassified into different classes.
Class A 0 - 127Class B 128 - 191Class C 192 - 223Class D 224 - 239Class E 240 - 255
8-8-8-8M.S.O Most Significant Ocate considering MSO
Through out class A, the MSB ‘0’ is constant in class B the Msbs are ‘101’ constant through out.Class D & E are not used for internetworking class D is used forMulticast network.“ E “ “ “ research.
class A0-0-0-0 should not be assigned for any divice127-0-0-0 is reserved for loopback127-0-0-1127-0-0-”127-0-0-” usually reserved for loopback127-0-0-”127-255-255-254
Hence 0 & 127 cannot be used for adressing so actual range will be 1 to 126.All ip addresses are divided into two.1.network I.d2.host I.d in class a address there is 1n\w I.d postion & 3 host I.d postion I,e N-H-H-H..Class A N-H-H-HClass B N-N-H-HClass C N-N-N-H
Network Ids are represented by 1s & host ids are by 0s.
Types of ip adresses IP address
public ip address private ip address
Public network: the public address is defined with routing over the Internet it is given by I.S.P & routing table is created on the internet.
Private network: for internal network I,e intranet, all the ip addresses Are governed by a body called INTERNIC. If we are a part of asiaPacefic then it is governed by APNIC.
We can run our private network with any ip addresses of our choice But it should not be connected to internet.
Range of addresses for private networkClass A 10.0.0.0 to 10.255.255.255Class B 172.16.0.0 to 172.31.255.255Class C 192.168.0.0 to 192.168.255.255
Private ip addresses donot have routing.To meet the demand of no.of networks, the network is broken Into smaller networks called subnets.Eg: find no.of subnets, hosts/s.n subnet mask & valid ip addressesFor a class c address.192.168.1.0/24‘24’ shows the network bits24= 3 octate position bits are enough, therefore no need to borrowAny bits from host position.=24 network & no hostDefault subet mask is 255.255.255.0 & valid ip addresses are 192.168.1.0 network
Switch An essential component of lan. Switches are of different types likeLayer 2 layer 3, layer 4, layer 5…..Layer 2 switch :Switch hub• Layer 2 layer 1• b.w is equal @ all ports b.w is shared• Identifies source with MAC cannot identifiy the source• Broad cast occur, till mac table alwaysbroad cast Is built• Collision occur when both A&B Many collisionsWants to reach D.• 1 broad cast domain 4 collision 1 broad cast domain 1 collisionDomains domain
Switches
Access layer Distribution layer Core layer
Access layer swithc: catalyst 1912 Catalyst – manufacturer, but it is now owned by cisco.12 port switch
Switch
standard edition enterprise edition
To configure VLANS,go for enterprose edition as standard editionWill not support VLAN.For uplinking or cascading 100mbps is minimum required.
Functions of switch1. Adress learning 2. Filter & forwarding3. Loop avoidance
4. Address learningBooting 1.blocking state (15 secs)
2.Listening state (15 secs)3.Learning stage (20 secs)4.Forwarding stage (20 secs)
The switch will always learn the MAC address from the source itselfThe source should atleast communicate once to learn the MAC address.
2. Filter & forwarding : store & forward cut through fragment freeOn access layer the default is fragment free we can change to anyOf the3 mentioned above.
1.store & forward: it stores the whole information (1500 bytesEthernet) into buffer, then checks for errors, looks for destination In MAC table and then forward.
2. Cut through: no error checking.as soon as a packet arrivesIt looks into MAC table & forward.
3.loop avridance: consider a seenario whr pci wants to communicate To pc2. Switch a makes entry of pc1 in its MAC table as it is a newSwitch. This looping is before the mac table I s made. This is calledInitial flood or broad cast storm.STP: spanning tree protocol. To avoid loops in case of a cascaded Switch stp is enabled by default.Parameters to select a switch1. Bridge priority (32768) default.(1-655355)2. MAC addressBridge id is calculated. Bridge id=bridge priority + mac address.Which ever the switch having least bridge ID will be elcted as root Bridge and others are non-root bridge. On root bridge the ports used For cascading are called designated ports. All the designated ports Will be at forwadingf state . In non root bridge from the two ports one will be selected as root port. This will be depending on the cost speed).least cost path (faster transmission) the other port will be blocked.
The “hello” packets that are sent by root bridge for every 2 sec to inform that it is working properly are called BPDUS; (bridge protocol data limits). If non root bridge do no receive 10 BPDUs for next 20secs then it is clear that the root bridge hasFailed.20secs – max age timeThen a new root bridge is selected.In the above eg:if switch A is selected as root bridge and ports A & B Of switch A are designated ports. Depending on the shortest pathsFor high speed & low cost one port of switch B is selected as root port& the other will be blocked.
ISDNIntegreted services digital network.It is a circuit switching technology approved by CCITT.ISDN PSTN• Digital analog• More bandwidth less• Multiple services like,• Voice,data,video etc.
ISDNBRI PRI
(Basic rate interface2b channels & id chennel)
european standard north american standard
30 bchannels 23 bchannels& &id channel id channel
‘B’channel – it is a bearer channel for data.‘D’channel – it is a delta channel for synchronizationIn bri each B channel = 64 kbps
d channel = 16kbpsMax 128 kbps BW in isdnIn PRI both B & D channels _= 64kbps.European – 2mbpsNorth american – 1.54 mbpsISDN will have a voltage of 90-110v
SPID number : (service profile identifier) to identify the link.Types of ISDN switchesEuro-basic net3U.S-basic 5 ess-at&t standardU.K-basic net3 & basic net5France-vn3 & vn4
Ss7 (signalling system7)Will be configured at the back bone side.
telco vn3/vn4 basic net3France India
ss7
E-series, I-series & Q-seriesE-tells about telephone network & ISDN networkI-tells about concepts & interfaces of ISDNQ-tells about signalling & switching of ISDN
DDRDail on Demand Routing
The main feature of ISDN is it dials & connects on request & Discounects when no data transfer is taking place. nat (network address translationIP NAT insideIP NAT out sideoverload
IPNAT inside: any request from th internal network will be NATEDTo public Ip address sending the request from internal networkTo Bri interface is overloading.When ever NAT is enable, the router will maintain a nat table.Nat table:
When nat t able is enabled nau request will be allocated a port Number after 1024. Above 1024 port numbers are reserved for otherServices. This allocation of port numbers is dynamic.
Configuring a DDR for ISDNConfig#int e0Config#ip adress 192.168.5.150 255.255.255.0Config#ip nat insideConfig#exitConfig-if#int bri 0Config-if#ip address negotiated Config-if#encapsulation PPPConfig-if#PPP authenticaiton PAP chap collinConfig-if#PPP chap hostname (username)Config-if#PPP chap password (password)Config-if#dialer string (tel.no.)Config-if#dialer idle timeout (time in secs)Config-if#dialer groupConfig-if#ip nat outsideConfig-if#exit
Ip address negotialted : this is when an ip adress is fetched kdynamicallyFrom ISP 7 donot have a permanent public I.P adress
Dialer – list range 1-10to configure router as a DHCP server
Config#ip pool <name> staring ip end ip.
Some ISDN commandSh int bri0Sh isdn status(layer 1 should be active. If not physical conectivity is lost)
Sh isdn activeSh isdn historySh ip network translaiton