+ 0 Votes Internet down -Precautionary steps muhammadsalmankhan October 5, 2013 at 3:22am PST Have an SLA in place with your ISP.Keep more than one or ISPs (Backups)First assess your own network, routing, etc. + 4 Votes I would first fire the guy who does not do his own homework robo_dev May 15, 2013 at 12:54am PST Then get to work looking into the issue.... + 2 Votes Are you surfing while taking your final exam? jqbecker May 15, 2013 at 1:05am PST If so, shame on you. + 0 Votes check the modem? Slayer_ May 15, 2013 at 1:45am PST Then work backwards + 0 Votes Verify a.portman May 15, 2013 at 3:24am PST Verify the Internet is down "everywhere". Then start at the connection and work in. Otherwise, start at the desktop and work out. + 0 Votes First confirm network access mjd420nova May 15, 2013 at 4:01am PST Using just a single laptop, connect to the modem to check access from there. If that works , it's the network/server if not access there, call your ISP. + 1 Votes First, make sure the call isn't from jtuck004 May 15, 2013 at 5:15am PST the boss's nephew, who tries to download the entire Internet onto his Chromebook and complains that "the Internet" is down 4x a week. And while you are in your chair, take a glance out the window and make sure there isn't a backhoe working next to the service entrace for your T1. With that out of the way, take your laptop and, listening for the sounds of grumbling from other users as you make your way to the main router, (so as to make sure it is really down for everyone). Then, by looking to make sure a light is on at the module where your T1 plugs in to the router, and thus making sure they haven't tripped the breaker, again, by plugging the coffee pot into the same receptacle, again, see if you have service to the switches by plugging in your laptop (into which you have hardoded an IP address and DNS server) to see if you get access at the router. You do have a straight-thru cable with you, right?Oh yeah, and if you find that Internet access is being provided by a modem, you aren't in as large an organization as you think. + 0 Votes KCCO mamccfts May 15, 2013 at 7:31am PST I would... Keep Calm and Chive On + 0 Votes Reboot it! aj42617 May 15, 2013 at 10:50pm PST *Check if the issue is 1 device or network wide?If network-wide this is an issue then reboot your router and/or Firewall, wait 5 minutes and check for connectivity.*Then contact your ISP for confirmation of connectivity. + 0 Votes My properly designed "large organization" network... Ryalsbane May 16, 2013 at 3:09am PST ...would continue to function. I would remain calm and focused due to having planned for this contingency when I designed (or redesigned when I took over for the previously ousted Network Manager/Admin) and implemented the network infrastructure to include redundant failover paths to the internet. My customers (company's employees and management) would not be aware of a failure until I announced it. I would know of the failure from the 24/7/365 monitoring and notification subsystems in place for this purpose.Assuming a basic go/no go monitoring with notification subsystem and that the local network is still functioning, I would do as lucvdv@ suggested. To get a quick, assessment of the scope of the failure and where the potential failure point is I would perform a traceroute to multiple internet destinations. The results will quickly tell me if the problem is with my local premises equipment, between the LAN and the ISP or with the ISP premises equipment. Once the scope of the problem is determined, if the problem is with local premises equipment I follow a reiterative "divide and conquer" process using traceroute, ping, netstat, nslookup, etc., to test for DNS and routing issues ultimately continuing through until the problem is fully isolated.