Every once in a while a piece of hardware will freeze up and needs to be rebooted. Try pinging laptop1 from PC0 and see how the packet fails. It does not get past the switch. Right-click the switch and power it off, then power it back on. Now try pinging laptop1. Frozen! 1024 1024 100 host 0 3.5 130 full True False laptop0 100 103 559,560 laptop False False 192.168.1.1 255.255.255.0 0.0.0.0 gw lo lo0 103 104 laptop0 lo0 lo 104 False lo0 127.0.0.1 255.0.0.0 0.0.0.0 ip Untagged eth eth0 103 105 laptop0 eth0 eth 105 False eth0 192.168.1.3 255.255.255.0 0.0.0.0 ip Untagged laptop1 100 123 680,160 laptop False False 192.168.2.1 255.255.255.0 0.0.0.0 gw lo lo0 123 124 laptop1 lo0 lo 124 False lo0 127.0.0.1 255.0.0.0 0.0.0.0 ip Untagged eth eth0 123 125 laptop1 eth0 eth 125 False eth0 192.168.2.2 255.255.255.0 0.0.0.0 ip Untagged net_switch0 100 109 400,320 net_switch False False 192.168.1.1 255.255.255.0 0.0.0.0 gw lo lo0 109 110 net_switch0 lo0 lo 110 False lo0 127.0.0.1 255.0.0.0 0.0.0.0 ip Untagged management_interface management_interface0 109 111 net_switch0 management_interface0 management_interface 111 False management_interface0 192.168.1.4 255.255.255.0 0.0.0.0 ip Untagged port port1 109 112 net_switch0 port1 port 112 False port1 0.0.0.0 0.0.0.0 0.0.0.0 ip Untagged port port2 109 113 net_switch0 port2 port 113 False port2 0.0.0.0 0.0.0.0 0.0.0.0 ip Untagged port port3 109 114 net_switch0 port3 port 114 False port3 0.0.0.0 0.0.0.0 0.0.0.0 ip Untagged port port4 109 115 net_switch0 port4 port 115 False port4 0.0.0.0 0.0.0.0 0.0.0.0 ip Untagged port port5 109 116 net_switch0 port5 port 116 False port5 0.0.0.0 0.0.0.0 0.0.0.0 ip Untagged port port6 109 117 net_switch0 port6 port 117 False port6 0.0.0.0 0.0.0.0 0.0.0.0 ip Untagged port port7 109 118 net_switch0 port7 port 118 False port7 0.0.0.0 0.0.0.0 0.0.0.0 ip Untagged pc0 100 100 246,560 pc False False 192.168.1.1 255.255.255.0 0.0.0.0 gw lo lo0 100 101 pc0 lo0 lo 101 False lo0 127.0.0.1 255.0.0.0 0.0.0.0 ip Untagged eth eth0 100 102 pc0 eth0 eth 102 False eth0 192.168.1.2 255.255.255.0 0.0.0.0 ip Untagged router0 100 119 400,160 router False False 0.0.0.0 0.0.0.0 0.0.0.0 gw lo lo0 119 120 router0 lo0 lo 120 False lo0 127.0.0.1 255.0.0.0 0.0.0.0 ip Untagged eth eth0 119 121 router0 eth0 eth 121 False eth0 192.168.1.1 255.255.255.0 0.0.0.0 ip Untagged eth eth1 119 122 router0 eth1 eth 122 False eth1 192.168.2.1 255.255.255.0 0.0.0.0 ip Untagged 100 102 pc0 eth0 109 112 net_switch0 port1 pc0_link_net_switch0 normal 126 103 105 laptop0 eth0 109 113 net_switch0 port2 laptop0_link_net_switch0 normal 127 109 114 net_switch0 port3 119 121 router0 eth0 net_switch0_link_router0 normal 128 119 122 router0 eth1 123 125 laptop1 eth0 router0_link_laptop1 normal 129 net_switch0 net_switch0 DeviceIsFrozen pc0 laptop1 SuccessfullyPings Default