OS X Mavericks Bug Consumes A Lot Of Bandwidth [UPDATED x2]

I keep an eye on my Internet usage as I only get 300GB of usage a month with my provider. That sound like a lot, but it isn’t and if I have to go over that limit, I have to pay for the overage. So it alarmed me when I looked in the web portal that my provider has for tracking my usage, it indicated that my bandwidth usage started going from 1GB a day or less to over 3GB a day. When I looked to see when this started, I found something interesting. My usage went up by just over 1GB the day after OS X Mavericks came out. It went up by just another 1GB the day after. I installed OS X Mavericks on my Macbook Pro on the day it came out and I installed it on my wife’s Mac Mini the next day. Clearly, Mavericks was consuming bandwidth.

To figure out why, I used an application called Little Snitch to monitor what was using my bandwidth. It didn’t take long to figure out. A service called OCSPD was chewing up the bandwidth. OCSPD is a daemon that is used by the system framework to perform security certificate verifications. This daemon caches or fetches from the network Certificate Revocation Lists (CRL) and deals with the Online Certification Status Protocol (OCSP). This process should not consume this much bandwidth. And there’s only two reasons why this process would take place. One is that an application is explicitly asking for the CRL to be refreshed. The other is that the CRL has a very short lifespan for whatever reason, so every time a process requests a certificate be checked the CRL is expired and a new one needs to be downloaded. Either way it’s clearly a bug. The question is, how to stop it from consuming bandwidth.

Here’s how I dealt with it. I went into Keychain Access and did the following:

• Click the Keychain Access menu and click preferences
• Click on Certificates
• Set Online Certificate Status Protocol (OCSP) to Best Attempt and Certificate Revocation List (CRL) to Off

It should look like this when you’re done:

So far this has resulted in my bandwidth usage to being normal again. I’m monitoring the situation to confirm that this continues to be the case. I also confirmed certificate related activities don’t seem to be an issue. I’ll update this story as I continue to troubleshoot the issue. Now this is just a workaround and not a fix. Thus Apple needs to fix this ASAP as I am sure that there are lots of people out there who are going through bandwidth on their Internet connections and either have no clue that they are or have no idea how to stop it. And if you have to pay for bandwidth, that will get expensive in a hurry.

So how about a fix Apple? Like now?

UPDATE: It seems that I am not alone with this issue. Some Google searches (which if I had done this last night would have saved me two hours of figuring this out) show a thread on the Apple Discussion Boards that documents this issue.

UPDATE #2: Please check out this post for an update on this issue.