Our lab has 2 subnet for the networking. One is Line-1 and another one is Line-2.
Today, we got trouble for printers. There printers are connected with Tcp/Ip. They are in the Line-1 networks. One of the person who uses Line-2 address asked me the printer trouble what she cannot use it. So, I checked it.
1. The network is working when that time. Sure I could shout ping to firewall and google.com. 2. All of Line-2 side machines could not use printer (shout printing queue and ping to printer address) but could use the networks. 3. From Line-1 machine we could use there printers. 4. Some time the printers response just a time when we shut ping. 5. Actuary, there printers could not access from others subnet.
IS Center sent mail me. That problem is happened by networking router. Some time that router block some of mac address. For just this case it happened on just printers. but some time it will happened on other PCs. They are fined some solutions for this problem.