Is this a cable modem? If so there will be one of a number of reasons it is doing this although most of them would need to be done by your network provider.
First of all on the cable there may be a low signal to noise issue that is preventing the modem from locking onto the network and your network provider would need to be contacted.
Second, the power the modem connects to the network is too high and the modem will not be able to hold this connection for more than a few moments and again the network provider would need to sort the problem.
Third, there may be a software/firmware issue with the updates in which case the network provider will probably be aware of this and a fix should be forthcoming soon.
Fourth, there may be a fault within the system causing this and again the network provider should be advised.
There is not a lot you can do other than make sure all the connections are tight and any cables that feed the modem are not snagged, kinked or twisted in any way. The correct way of rebooting is to switch off all equipment connected to the modem, then switch off the modem. Wait at least 30 seconds then switch on the modem. Once all the lights that should be on are on then switch on any routers, laptops, tablets etc. There is not a lot you can do apart from that although you could check the modem itself. This would be done be looking at the label on the modem itself. This will give you a web address along the lines of 192.168.xxx.x as well as user and password details. This would give you information about connection status, signal levels, noise, time and other issues.
