Você pode usar lsof
e watch
para fazer isso, assim:
$ watch -n1 lsof -i TCP:80,443
Exemplo de saída
dropbox 3280 saml 23u IPv4 56015285 0t0 TCP greeneggs.qmetricstech.local:56003->snt-re3-6c.sjc.dropbox.com:http (ESTABLISHED)
thunderbi 3306 saml 60u IPv4 56093767 0t0 TCP greeneggs.qmetricstech.local:34788->ord08s09-in-f20.1e100.net:https (ESTABLISHED)
mono 3322 saml 15u IPv4 56012349 0t0 TCP greeneggs.qmetricstech.local:54018->204-62-14-135.static.6sync.net:https (ESTABLISHED)
chrome 11068 saml 175u IPv4 56021419 0t0 TCP greeneggs.qmetricstech.local:42182->stackoverflow.com:http (ESTABLISHED)