This is a hex dump of a TCP keepalive.
fc aa 14 30 62 b6 44 d9 e7 ff 53 63 08 00 45 00 00 34 3f 75 40 00 36 06 c4 d6 c3 c9 09 25 c0 a8 b2 e1 56 33 ee 46 d5 3a fe 23 4b 11 33 3f 80 10 01 f5 23 8d 00 00 01 01 08 0a 8e 21 17 ee ab 59 29 30