Mavericks and Failed ARP causing network drops!

HI MacStadium, We are experiencing a couple of issues and were wondering if there caused by the same thing you are describing in this post. We are using Mavericks clients and server and have been fighting this since Mavericks came out. The network users home folders are hosted on the server. The two issues we are facing is the mail app keeps asking for password (and does not save it when reentered) and in server app users do not get disconnected in file sharing when the user logs out. The mail app issue only happens after switching users on the same client machine. The only fix for this we have found is to reboot the client on logout. We have found a post that mentions something about the ethernet adapter. Here is the link to the post. discussions.apple.com/thread/5547625?start=45&tstart=0

Do you think using the USB to ethernet adapter on our server will help us with either of these issues? Any feedback or insight would be greatly appreciated.

I had similar issues with my MacBook Pro (late 2013) and explored a lot into this problem. Here[0] is a detailed explanation and solution.

http://pankajmalhotra.com/ARP-and-ethernet-issues-with-osx-mavericks/

Hope you find it useful.

Cheers !

Bitgeeky

After the last update (July-August 2014) on OS X 10.9.4, MacBook Pro, the same problem appeared. Losing 3-50% of the packets. Ehternet is affected on both my (large+fast) work networks and not at home. Setting net.link.ether.inet.arp_unicast_lim to zero does not help.

Surely, I don't have to stress that the guys in the IT support are not in the least concerned by the woes of a Mac user in a company with >500 Windows users. So, please please Apple, fix this.

While this sysctl solution works, it should be noted that the RFC states that sending Unicast ARP messages is perfectly valid. See Section 2.3.2.1 of RFC1122, "ARP Cache Validation." for details.

The onus is on the network vendors to fix their bugs, and not on Apple to work around this issue.

-DDV

(Senior Network Administrator for the past 15 years)

Thank you for the update, it is still valuable information in a way.

Certainly what you say is correct, vendors should fix this bug. Please note that the sysctl solution DOES NOT always work, because jwsullivan, codythedog and myself have reported that it doesn't.

And now, try to see it from a user point of view. The network vendors did not change anything this Summer, I simply installed the next update on my OS. And now my network doesn't work, while my admins and Cisco couldn't care less. If I knew that ethernet connection at work is not going to be functioning on my laptop, I would have never suggested to my employer to buy it for my.. work.

Thanks for your reply. It is good to have both sides represented!

I just received news that my network vendor (Arista Networks) has reproduced this problem on a very specific hardware platform (which we use), and are implementing a fix.

Good news for us, not much help to those using Cisco or other vendors equipment, nor to the users on said equipment.

-Dave

An update: the problem is gone after installing Yosemite.

Apple should certainly fix this!

In an attempt to provide some form of quality of service, they've filled the network with unnecessary traffic as well. I'm in IT at a medical school in which the D.O. student body gets an iPad and Macbook pro, so our wireless network is saturated with all of this unnecessary traffic, and we are also getting lots of complaints about dropped connections in well covered areas. This has been such a headache, as OS X doesn't have readily accessible network tweaking tools to remedy this. I hope they fix this soon.