Why is OS X connecting to apple on multiple port numbers?

Question

Why is OS X connecting to apple on multiple port numbers?

My router is reporting that at random times, the IP addess of my airport on my imac is trying to connect to an IP address (which seems to belong to Apple - 17.172.208.43) on multiple sequential ports.

Didnt do this before Mavericks. What could be causing this?

2013/10/27 11:16:51 -- [DOS][Block][tcp_flag, scanner=fin_wo_ack][192.168.0.24:51864->17.172.208.43:443][TCP][HLen=20, TLen=52, Flag=F, Seq=3462246037, Ack=0, Win=65535]

2013/10/27 11:16:51 -- [DOS][Block][tcp_flag, scanner=fin_wo_ack][192.168.0.24:51865->17.172.208.43:443][TCP][HLen=20, TLen=52, Flag=F, Seq=1654792132, Ack=0, Win=65535]

2013/10/27 11:16:51 -- [DOS][Block][tcp_flag, scanner=fin_wo_ack][192.168.0.24:51866->17.172.208.43:443][TCP][HLen=20, TLen=52, Flag=F, Seq=4063774636, Ack=0, Win=65535]

2013/10/27 11:16:51 -- [DOS][Block][tcp_flag, scanner=fin_wo_ack][192.168.0.24:51867->17.172.208.43:443][TCP][HLen=20, TLen=52, Flag=F, Seq=3325480430, Ack=0, Win=65535]

2013/10/27 11:16:51 -- [DOS][Block][tcp_flag, scanner=fin_wo_ack][192.168.0.24:51868->17.172.208.43:443][TCP][HLen=20, TLen=52, Flag=F, Seq=1299003110, Ack=0, Win=65535]

iMac, OS X Mavericks (10.9)

Posted on Oct 27, 2013 4:17 AM

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Answer 1

Best reply

iW00

Level 6

8,488 points

Oct 27, 2013 4:21 AM in response to applekentuser

You can find answer here: Well known TCP and UDP ports used by Apple software products

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Answer 2

Oct 27, 2013 6:11 AM in response to iW00

Thanks, According to the list it relates to Back To My Mac, however pre Mavericks there was no such notifications from my router as currently it is causing multiple Denial of Service notification emails.

Ports, 51864, 51865, 51866, 51867, 51868 etc…

The internal IP address being used is the one for wifi, Why would it only occur on the wireless side? The machine is also on ethernet with a different IP.

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Answer 3

Feb 13, 2014 12:41 AM in response to applekentuser

Just to link your posts with mine for future reference to others searching for this, I'll post my thread with a Draytek Router and your other thread in a simialr vein .

Interestingly my ' outgoing attempts' started at a similar time to yours....but I never upgraded to mavericks...wonder if it is some other Apple system change I am getting outgoing 'attacks' blocked from iOS devices to ..iPad and iPhone.

https://discussions.apple.com/thread/5485834

https://discussions.apple.com/thread/5891329?answerId=24837014022#24837014022&ac_cid=op123456#24837014

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