How to Configure Ethernet and Serial Interface on Cisco Router
How to Configure Ethernet and Serial Interface on Cisco Router
Different types of interfaces on the routers help the router for the transmission of data from source to destination. Some of the interfaces are the serial interface, Ethernet interface, Fast Ethernet interface, token ring, FDDI, Gigabit internet etc.
The interfaces must be configured with appropriate IP addresses, subnet mask etc. To get the details of all the interfaces present on the router along with their naming convention, use the following commands:
CISCO-ROUTER> ENABLE
CISCO-ROUTER# SHOW IP INTERFACE
OR
CISCO-ROUTER# SHOW IP INTERFACE BRIEF
Enable command is used to allow an administrator to enter privileged EXEC mode from User EXEC mode. Router’s Internetwork Operating System prompts for a the password in case it is configured with a password.
” Show IP interface” displays the list of all interfaces present on the router, IP addresses assigned to them and the status of the interfaces, active or inactive.
Configuring an Ethernet interface:
All the configurations are done from global configuration mode. To configure an interface, the administrator has to enter into interface configuration mode. All the configurations on the interface have to be done here. The lists of commands that help to configure an Ethernet interface are as below:
CISCO- ROUTER> ENABLE (ENTERS INTO PRIVILEGED EXEC MODE)
CISCO-ROUTER# CONFIGURE TERMINAL (Allows to enter global configuration mode)
CISCO-ROUTER(CONFIG)# INTERFACE FA0/0 ( Opens interface configuration mode and allows an administrator to configure fast Ethernet 0/0. FA represents Fast Ethernet.)
CISCO-ROUTER(CONFIG-IF)# IP ADDRESS 172.26.0.1 255.255.255.0 (Assigns IP address to the Fast Ethernet 0/0. 172.26.0.1 is the IP address assigned to the interface and 255.255.255.0 is the subnet mask of the IP address that has been assigned to the router).
CISCO-ROUTER(CONFIG-IF)# NO SHUT DOWN ( By default all the interfaces on the router are inactive or shut down mode. No shut down makes the inactive interface active.)
CISCO-ROUTER(CONFIG-IF)# END (Enters privileged exec mode)
CISCO-ROUTER# COPY RUN START ( copy all the information in the running configuration file to the startup configuration file)
Configuring Serial Interface:
The serial interface is used to connect a router to another router when the distance between two routers is large. The serial interface can be Data Communication End (DCE) or Data Terminal End (DTE).
CISCO- ROUTER> ENABLE (To enter into privileged exec mode)
CISCO-ROUTER# CONFIGURE TERMINAL (Allows to enter global configuration mode)
CISCO-ROUTER(CONFIG)# INTERFACE s0/0 ( Opens interface configuration mode and allows an administrator to configure s 0/0. ‘s’ represents Serial.)
CISCO-ROUTER(CONFIG-IF)# IP ADDRESS 172.26.0.1 255.255.255.0
CISCO-ROUTER(CONFIG-IF)# clock rate 64000 (assigns clock, helps in synchronization)
CISCO-ROUTER(CONFIG-IF)# bandwidth 64 ( Sets the bandwidth)
Clock rate and Bandwidth are assigned at DCE end.
CISCO-ROUTER(CONFIG-IF)# NO SHUT DOWN
CISCO-ROUTER(CONFIG-IF)# END
CISCO-ROUTER# COPY RUN START
To disable any interface, enter the interface configuration mode and give the command “shutdown”
CISCO-ROUTER(CONFIG-IF)# shutdown
To add description,
CISCO-ROUTER(CONFIG-IF)# description main block interface
Description helps to identify the interface easily.
Read more
- What is Fast Ethernet Interface, Gigabit Ethernet Interface, and Serial Interface in Cisco Router
- What is Subinterface in Cisco Router
- What is Loopback Interface in Cisco Router and How to Configure
- What is null interface and how to configure