traviscross
What do > and ? mean?
In the images below, what do > and ? mean?
I presume that > means that a response to the ping was received, but that the time between the ping and the response was greater than the largest number of milliseconds shown (i.e. 64 or 2319).
Does the ? mean that no ping response was received? Does it imply anything about routing to or through that host? That is, could packets be routed through 162-207-92-1.lightspeed even during a long series of question marks?
mtr works by sending "faulty" packets into the world. When a router notices the issue, it is considered nice that it would return an error packet. (When the error happens for real, you'd be waiting for 30 seconds if no error were returned, or get an immediate "that won't work" when it is). (Think of sending out mail, and the mail service dropping your mail items: "not enough postage paid" instead of returning your item with an explanation).
So most routers are configured to return the error messages. Some are not. It is possible a router was configured not to return the errors for a short time. I think that's unlikely. If you see this happening and packets are still being routed, then my guess was that the routing changed, and at that position in the path another router took over. And that one was configured to not return any error packets.
