Skip to main content

Different Types of Router Memory

ROM

ROM is read-only memory available on a router's processor board. The initial bootstrap software that runs on a Cisco router is usually stored in ROM. ROM also maintains instructions for Power-on Self Test (POST) diagnostics. For ROM Software upgrades, the pluggable chips on the motherboard should be replaced.

Flash Memory

Flash memory is an Electronically Erasable and Re-Programmable memory chip. The Flash memory contains the full Operating System Image (IOS, Internetwork Operating S
ystem). This allows you to upgrade the OS without removing chips. Flash memory retains content when router is powered down or restarted.

RAM

RAM is very fast memory that loses its information when the router is shutdown or restarted. On a router, RAM is used to hold running Cisco IOS Operating System, IOS system tables and buffers RAM is also used to store routing tables, keep ARP cache, Performs packet buffering (shared RAM). RAM Provides temporary memory for the router configuration file of the router while the router is powered on.
RAM Stores running Cisco IOS Operating System, Active program and operating system instructions, the Running Configuration File, ARP (Address Resolution Protocol) cache, routing tables and buffered IP Packets.

NVRAM (Non-volatile Random Access Memory)

NVRAM is used to store the Startup Configuration File. This is the configuration file that IOS reads when the router boots up. It is extremely fast memory and retains its content when the router is restarted.
Labels:

Comments

Post a Comment

Popular posts from this blog

Cisco three-layer hierarchical model

Because networks can be extremely complicated, with multiple protocols and diverse technologies, Cisco has developed a layered hierarchical model for designing a reliable network infrastructure. This three-layer model helps you design, implement, and maintain a scalable
Post a Comment
Read more

Access Control Lists (extended)

Access Control List  or  ACL  is a technic of controling network traffic. It is a list of rules with which traffic flow can be manipulated - permitted or denied. By default, traffic flow from the interface with the higher security level (for example "inside" interface) to interface with the lower security level (example "outside" interface) is allowed by default, but the flow of traffic from "outside" to the "inside" interface must be explicitly permited. 
Post a Comment
Read more

Classes of IP addresses

TCP/IP defines five classes of IP addresses: class A, B, C, D, and E. Each class has a range of valid IP addresses. The value of the first octet determines the class. IP addresses
Post a Comment
Read more