External Components of
Router:
LAN interfaces
WAN interfaces
Administration interfaces
LAN Ports:
- Ethernet 10 Mbps
- Fast Ethernet 100 Mbps
- Gig Ethernet 1000 Mbps
- AUI(Attachment Unit Interface)
(E0)-15 pin
Attachment Unit Interface:
- Commonly found on some old
platform
- AUI pin configuration is 15 pin
port (Ethernet LAN using 15pin instead of RJ45)
- Transceiver is used for converting
8 wires to 15 wires. i.e., RJ45 to 15 pin converter
WAN Ports:
- Serial Ports
- 60 pin or 26 pin smart serial
- ISDN interface (BRI) – RJ45 (used
for ISDN wan connections)
Administration Ports:
Console Port:
- It is RJ45 Port
- Used for local administration, initial
configuration, password recovery
Auxiliary Port:
- Its an RJ-45 port
- Used for remote administration
- Uses the console cable connecting
to modem
Internal Components of
Router:
ROM:
- Loads the bootstrap programs and
searches for the IOS (Flash/TFTP/ROM)
FLASH:
- Stored IOS
NVRAM:
- Stores configuration (permanent)
- Startup-config
RAM:
- Stores configuration (temporary)
- Running-config
Booting process of Cisco
Router:
POST – power on self-test checks the
hardware
ROM – loads the bootstrap program
and searches for the IOS
FLASH – stored IOS
NVRAM – stores configuration and
startup configuration
RAM – stores configuration and running-config
Modes on Cisco Routers:
Setup Mode - If NVRAM is Blank
User Mode - Only some basic
monitoring
Privileged Mode – monitoring and
some troubleshooting
Global Configuration Mode – All
configuration that effect the router globally
Interface Mode – Configurations done
on the specific interface
Rommon Mode – Reverting password
Fixed Router:
- All ports are integrated on motherboard(no slots)
- Non upgradable cannot add and remove the interfaces
- eg., 2500, 2800 router series
Modular Router:
- Have slots where we can add or remove cards
- Distribution and Core layer router is an example of modular router
- eg., 1600, 1700, 1800, 2600, 2800, 36