On my MacBook Pro laptop running OS X El Capitan (10.11.6), I've been losing Internet connectivity periodically. Though it appears I still have Wi-Fi connectivity, when I attempt to access websites through a browser I find that I can't access sites at times, though a moment before I had no issues browsing the Web. Firefox will display a "Server not found" message. If I go to a Terminal window and try to ping any IP address, I see "request timeout" messages.
$ ping 8.8.8.8 PING 8.8.8.8 (8.8.8.8): 56 data bytes Request timeout for icmp_seq 0 Request timeout for icmp_seq 1 ^C --- 8.8.8.8 ping statistics --- 3 packets transmitted, 0 packets received, 100.0% packet loss $
If I check the status of the WiFi connection using the airport command, I see that it is very noisy, though the signal stength is good, which I would expect, since the laptop is only a few feet from the wireless router.
$ /System/Library/PrivateFrameworks/Apple80211.framework/Versions/Current/Resources/airport -I
agrCtlRSSI: -39
agrExtRSSI: 0
agrCtlNoise: -93
agrExtNoise: 0
state: running
op mode: station
lastTxRate: 73
maxRate: 72
lastAssocStatus: 0
802.11 auth: open
link auth: wpa2-psk
BSSID: 94:44:52:4a:43:40
SSID: Rain
MCS: 7
channel: 11
$[ More Info ]
