Routers and RAM

TWXTWX Member Posts: 275 ■■■□□□□□□□
So I'm asking because around those Internets I'm finding conflicting information- some sources say that IOS images that call for more RAM can be made to boot with less RAM than Cisco calls for, but when I attempted it I had some errors.

Basically I'm trying to get IPv6 support working on some 2600-series (non-XM) Routers with 48MB RAM and 16MB Flash. Given that they have 48MB I could probably order 2x 32MB 100pin 5V EDO SODIMMs, but just looking for anyone else's experience. All the IPv6 and OSPFv3 capable IOS images call for 64MB as far as Cisco calls it.


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    clarsonclarson Member Posts: 903 ■■■■□□□□□□
    the 2600 stores the ios on flash. at boot that image is loaded into ram. So, if the image will run in the available ram, but is too large to fit on the flash. You can still boot that image from a tftp server. And, cisco tells their customers how much memory is necessary for the router to comfortable do its job. which includes lots of io buffer space to handle data throughput. But, in a lab environment not only is throughput less also memory requirements for things like routing tables are less. So, sometimes you can get by with less ram than what is recommended. You'll get error messages about there not being enough memory. but if it works your good. but, if it keeps crashing on you, then your going to have to get more memory to keep that from happening.
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    theodoxatheodoxa Member Posts: 1,340 ■■■■□□□□□□
    Memory is cheap (on eBay). If you are comfortable opening up the case, I would just upgrade to whatever the maximum for your model is.

    BTW, there are a few folks selling memory on eBay. Make sure to click "US Only" when searching or you'll get results from China mixed in. I've ordered from a guy in South Carolina many times with no issues.

    Upgrading System Memory, Internal Flash, and Boot ROM in Cisco 2600 Series Routers - Cisco
    Security: CCNA [ ]
    Virtualization: VCA-DCV [ ]
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    TWXTWX Member Posts: 275 ■■■□□□□□□□
    Picked up some memory cheap from a local guy that sells Cisco stuff. Took one of my routers and my laptop to the coffee shop to meet up to test it. They're both at 64MB now. Unfortunately the flash that he thought was 32MB was actually 8MB. So, still at 16MB flash, but since the TFTP server is in the same rack as the routers it isn't exactly a burden to copy the IOS from TFTP at boot...
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