Dec 23

Cisco ASR 1001 Memory

We recently got 2 new ASR 1001s at work to complement 2 we already had. Stupid me but specified 4GB RAM on the order not 8GB that we needed 🙁 The size of the full BGP table now means that 4GB is starting to get to be a bit of a tight squeeze on 4GB once you add on other services.

But being a MSP we have RAM coming out of ears, we must have SOMETHING suitable around here……

Well turns out we did, but it took a lot of digging to find it!

Before I go on but, I think i would be silly not to put the following here:
What I describe below goes against the Cisco recommended hardware for these routers.
This MAY invalidate your warranty on the device, or invalidate your smartnet subscription.
I am in NO WAY responsible if you follow this and something happens to your router and or warranty status.
If you don’t know what I’m talking about below, I strongly urge you to stop right here and order the right stuff.
You follow this advice at YOUR OWN RISK.

The memory in the router that came stock was very unhelpful as it was basically generic, no speed or details to find. Because the RAM is Cisco proprietary memory, even the third party stuff doesn’t say what it is.

But It turns out that the RAM going into the Router is: DDR2 PC-5300p (Registered 667)
240P-DDR2-2GB-PC5300 ECC-REG

Wikipedia has the full tech info here

Additionally, the Cisco site here has the memory configurations supported, but I found that I could get 8GB in the router with 2x 4GB DIMMS in slots 0 and 1. So again what I describe in the article is AGAINST CISCO RECOMMENDATIONS and you do so AT YOUR OWN RISK.

Being registered RAM, you will be hard pressed to find it at your local PC store, this isn’t normal Desktop RAM. Its high end server RAM. If you do go down this road but, I would suggest a full memtest of the memory before you put this into production.

If you are going to buy RAM for your routers but, my suggestion would be the third party Cisco approved RAM. But if you are up against the wall at 2AM, the above might get someone out of trouble. If it does, leave a comment, I’d be interested to know how many people out there are as much of a cowboy as me!