Determining the Cisco Memory in Your Router

Most Cisco routers have the capability to be given a memory upgrade. Cisco routers and firewalls generally come with half of their maximum RAM installed.  These devices either have one free memory slot, or come with a SIMM or DIMM in a slot that will accept a replacement of greater memory capacity. However, because of the breadth of Cisco's product line, determining your Cisco memory size is not necessarily simple.

There are two ways to identify your Cisco memory size. The preferred method is to simply ask the device while it is in operation with the "show memory" command, at the command line interface on Cisco IOS systems. (Note that some utilities may offer the same functionality through the use of a GUI.) When called, the command will return a hexadecimal code that corresponds to a specific memory size. There is variation between different systems, so you need to refer either to your product documentation, or to the product support resources offered on Cisco's website for a table of hex codes and their corresponding Cisco RAM size values for your devices.

The alternative method is to visually identify the Cisco memory capacity. If the memory is installed, this is rarely advisable, unless plans already exist for the device to be disconnected from the network, and traffic can be routed through redundant pipes. If you choose to check your router's memory capacity this way, power it down and unplug it, unscrew the case, and locate DRAM slot. Remove the RAM and note the part number. A search of Google or the Cisco web site will render the capacity of your RAM, its manufacturer, and all other relevant data.

If an upgrade is in order, PC Wholesale carries a complete line of both Cisco Original/OEM and third party memory modules and Flash cards for every Cisco router, firewall, and switch.  Check out the Cisco Memory section to find your model.