here's the situation:
cable internet provider: cox
# of computers on network: 15+
network hardware: cox cable modem. watchguard soho 6.4.x firebox/router. 20 port hub system, plus 4-port netgear hubs around the network.
wires going into watchguard router: 1 from cable modem. 1 from security camera dvr. 1 going to 20 port hub system. 1 going to computer station.
network has been running smoothly. internet has been running smoothly for several years. wed morning, we experienced an internet outage (but not network) that took about an hour for cox to figure out how to fix it. after all the "it's not us. looks fine on our end, etc etc." they fixed it by clearing the arp cache on the watchguard router and resetting the cable modem. sometimes it took multiple tries. in any case, the techs were always stumped as to what was going on.
then it happened again thurs morning. again, same situation from the cox techs...bounced around, nobody could understand it. clearing the arp cache worked again, but again took several attempts.
next it came back that afternoon. same solution. happened again that night and has not been fixed.
one cox tech suggested it could be because of some upstream frequency that was modified on wednesday, although he couldn't understand how it was related.
another interesting point: i could not access my watchguard router (via it's internal ip address) while the cox cable modem was online, but our internet was out. on the flip side, i could access it as soon as my cable modem went down (and our internet was out)....i could also access it fine when both the cable modem and internet were up.