Rahul Khadse
TFTP server is modified form of FTP. It is used to transfer file without performing authentication. TFTP has only home directory, in which subdirectories are not allowed. Directory browsing is not allowed in the home directory.
TFTP is the udp-based protocol, which works on port no 69. TFTP has following features in comparison to the FTP.
- Only get file and put file service is available
- Authentication is not supported.
- Home directory may not have sub-directories
- Directory browsing is not allowed
Installation and Configuration of TFTP server
In windows system, we have to execute following steps to use
the pc as TFTP server.
- Download TFTP server software from internet.
- Install the TFTP server software on pc.
- If software is not installed as the service then software should be running on screen . Configure home directory of server or used default.
Functions to be perform with the help of TFTP server
- To boot router from TFTP server
- Backup IOS and configuration
- Restore IOS and configuration
- Upgarde IOS
(1) To boot from TFTP server
i) Run the tftp server s/w on pc. And copy IOS
image file in the Home directory of tftp server.
ii)
Test connectivity between router and tftp server.
iii) On router use following commands:-
Router#conf
ter
Router(config)#boot system tftp c1700-1s-mz.122.3.bin 10.0.0.18
Router(config)#exit
Router#copy
runn start
Reload the device. Make sure that configuration register set
as 0x2102.
2) To backup IOS
i) Test
connectivity and make sure TFTP server is running.
ii) Type command: -
Router#show
flash (note the IOS filename)
Router#copy
flash TFTP
Source
filename = ?
Destination
filename=?
IP
of TFTP server=?
To backup Configuration
i) Test
connectivity and make sure TFTP server is running.
ii) Type commands: -
Router#copy
running-config tftp
Or
Router#copy
startup-config tftp
Remote IP: ________
Destination
Filename: ______________
3) To restore Configuration
i) Test
connectivity and make sure TFTP server is running.
ii) Make sure
configuration file is present in home directory and note the filename.
iii) Type commands:
-
Router#copy
tftp running-config
Remote IP: __________
Source Filename: _______________
Destination Filename[running-config]: _______________
4) Restore/Upgrade IOS
There are four different conditions in which we can
restore/upgrade ios
Case 1: old ios is present and flash is in read/write
mode.
i) Copy ios
image in tftp server’s home directory.
ii) Test
connectivity and make sure tftp server is running.
iii) On
router use commands: -
Router# copy tftp flash
Source file: -
Destination file: -
IP
address: -
Erase Flash [y/n]:
Case2: old ios is present but flash is in read only.
i) In this
case, we have to set config-register to 0x2101 to boot the router from
incomplete ios.
ii) After
booting the flash will be read/write mode. Now use same command as in condition
case 1.
iii) When ios
loading is complete reset config-register to 0x2102.
Case3: old ios is not present but incomplete ios is
present in bios.
The router will automatically boot from
incomplete ios. And we have to execute same commands as in case1 and case2.
Case4: complete ios and incomplete ios is not present
in router.
There are two methods to load ios with the
help of Rom Monitor mode.
Method1: loading ios using
xmodem
In this case we have to use xmodem command and
the ios will be loaded with the help of console cable. Tftp is not required in
this case.
i) Enter to the Rom Monitor and type following command.
Rom Mon
1>xmodem <filename>
ii) When router display a message “ Ready to
receive file” then click on HyperTerminal then Transfer>> Send
file>> use browse to select file>> select protocol xmodem>> send.
Method2: in this case we have to use tftp server in
Rom Monitor.
i)
Connect the pc tftp server make sure tftp is running and ios image present in
the home directory.
ii) Enter to the Rom Monitor mode and type following
command.
Rom
Mon>IP_ADDRESS=10.0.0.2
TFTP_SERVER=10.0.0.1
TFTP_FILE=<filename>
DEFAULT_GATEWAY=10.0.0.1
IP_SUBNET_MASK=255.0.0.0
>tftpdnld
==> When ios transfer is completed then type command.
Rom
Mon>boot
Router#show version
To view from where ios boot.
Router#show flash
Resolving Host Name
In router, we can communicate with the help of IP
address as well as host name and domain name. There are two methods to resolve
hostname into IP address.
1) Using local hostname database
We can use
local hostname database by using IP host command. We can use this command with following syntax: -
Router#config terminal
Router(config)#IP host <name> <IP address>
Router(config)#IP host abc 202.144.55.6
Router(config)#exit
Router#show hosts
Router#ping abc
2) Using a DNS server
We can
configure router to send DNS queries to DNS server. The DNS server will resolve hostname and then pc or router will try
to communicate with destination. We can create maximum 6 IP.
Router#config terminal
Router(config)#IP name-server <IP> [<IP2>]
Router(config)#IP name-server 202.56.230.6
Router(config)#exit
Managing Telnet connection
Our router is able to telnet other devices as well as
other devices can also perform telnet to our router.To allow Telnet access to router --> For this purpose we have to configure IP address, vty password and enable secret password. IP must exist between client and router. When router will be able to perform telnet access. On telnet client we have to use following command :--
Router#Telnet <IP of router>
To display connected users --> Router#show users
To disconnect a user
To telnet a device from router
Router#telnet <IP>
Or
Router>telnet <IP>
Or
Router>telnet <IP>
To exit from telnet session
Router#exit
To exit from a hanged telnet session
Ctrl+shft+6
X
Router#disconnect
To display connected session
Router#show sessions
This command shows those sessions, which are created or
connected by us.
If we want anyone can telnet our router without
password then on the line vty type command “No Login”.
Posted in: CCNA
