why does the Cat5 router connection port not always work?

sometimes it takes a while for the light to come on or I change cables or even turn it on and off again? I would like it work every time consistently. Most of the time you plug the cat 5 in and get a Immediate yellow light on rear but sometimes its just black and does not do a thing, this happens at shows and at home. I have 3 routers and 5 cables. I take 2 routers and 3 cables to the gig just in case. But it worries me that something may be wrong with the unit. Has Anyone else experienced this?

If you have DHCP enabled, you should boot the router, wait until it is ready and then turn the mixer on.