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Question about DRAM and Flash

e24ohm

Folks:
I have a question about DRAM and Flash on routers. I understand Flash is used for the IOS image, and DRAM is used for the Startup-config file; however, what is a good recommendation for ram and flash amount on a router?

I am looking at 32M DRAM and 8M Flash; however, the number really mean nothing to me and I only know book statistics, so any real world examples will be great - Thanks….cheers!!!

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Comments

alan2308

The amount of memory and flash you need varies with the router model. Without knowing which router, the numbers really are meaningless as two different routers will have different memory requirements for similar IOS images. It can also differ based on what you intend to do with the router. If you're studying for the CCNA, you don't need as many features as if you're studying for the CCIE so you don't need as large of an IOS image and therefore don't need as much memory and flash.

The tl;dr version: it depends...

odysseyelite

Like Alan said, it depends on the model of the router. I'm using 2600xm's and mazed out the router to 256mb. It was a cheap upgrade and was needed to run 12.4 IOS.

What are you trying to accomplish? Are you looking at buying routers to pratice on? Of that is the case, make sure you have enough to run the IOS you want to run. My old 3640 runs 128bm dram and 32mb flash and runs 12.4, so that should give you an idea.

e24ohm

I am looking at getting a cheap 1721 for my home network. The fan in my 2600 is a killer, and I don't want to hear it under my desk.

Slowhand

If you're getting a 1721, then you want to make sure it maxes out at 128MB RAM and 32MB flash, (I ended up buying one that only had 16MB flash on eBay, and it won't run the version of the the IOS I want it to.)

One thing you can do to get more familiar with the hardware requirements of the various platforms is to check out the Cisco Feature Navigator. Particularly if you search by software or image name. The results will show you how much RAM and flash memory is needed for each image on each piece of hardware.

e24ohm

Slowhand wrote: »

If you're getting a 1721, then you want to make sure it maxes out at 128MB RAM and 32MB flash, (I ended up buying one that only had 16MB flash on eBay, and it won't run the version of the the IOS I want it to.)

One thing you can do to get more familiar with the hardware requirements of the various platforms is to check out the Cisco Feature Navigator. Particularly if you search by software or image name. The results will show you how much RAM and flash memory is needed for each image on each piece of hardware.

What would be a good IOS to start with? I have my 2650s in storage and I have not reviewed IOS images in a few months, so I have no clue, nor remember what to look for.

Thanks...Cheers!!!

odysseyelite

You want at least 12.4 or higher.

Slowhand

You're going to want version 12.4 or 12.4T, and the higher the release number, (in parentheses after the version number,) the better. For the CCNA, any feature set - base IP, enterprise, etc. - should do just fine, but the more advanced you can get, the better off you'll be for any future exams. Check the Feature Navigator and see what version of 12.4 or 12.4T your hardware supports.

e24ohm

odysseyelite wrote: »

You want at least 12.4 or higher.

Thanks so much. In addition, what models support 2x Fasterethernet ports - was that the 28xx series?

e24ohm

Need more resources for detailed information about: MD, GD, LD, ED, MM? I have read the links on the Cisco site; however, just require more real world implymentation knowledge. I am having a hard time understanding these levels.

Thanks so much.

odysseyelite

The 2600xm's support 2 FastEthernets. 2611xm,2621xm,2561xm. Not sure about the 1700's as I have not used them. These routers are modular so you can buy the module and install extra ports.

Slowhand

The 1700 series routers each have one FastEthernet port built in.

e24ohm

Thanks so much for the insite....