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Unread 01-03-2015, 14:54
jhersh jhersh is offline
National Instruments
AKA: Joe Hershberger
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Re: Not able to connect to roborio mDNS name on OSX

Quote:
Originally Posted by virtuald View Post
We did some investigation on this on the robot's network, and the two mdns processes are definitely conflicting with each other. I can't imagine why both are enabled -- I suspect an oversight?
It is actually not an oversight as it turns out. I was as surprised as you at first. I dug into the reason and found out that the system configuration people have settled on avahi as the mDNS software for the platform. Unfortunately for the vision group, avahi does not have an API to return all of the IP address records returned by the queried device. The way Axis implemented mDNS on their cameras is incompatible with this since it returns a link-local address (If link-local could work consistently when you have more than one network interface it wouldn't matter.) even when the camera has a DHCP or static configured address, and in an unreliable order. The maintainer of avahi, Lennart Poettering, has made it clear that he doesn't want to support returning more than one IP address. This limitation does not exist with mdns-responder, so the vision team opted to run that as well!

I'm not sure there is a way to stop running both and still support Axis cameras, but hopefully there is a way to make avahi responses make it back to the mac. Do you have pcap files showing the working vs. non-working traffic?