My apologies, turns out there's four IP addresses used by the load balancer for the outgoing server:

205.188.80.38
205.188.81.38
64.12.166.38
64.12.105.38

Sean McRobbie wrote:
Looks to be a typo somewhere: 205.188.80.38 versus 205.188.81.38 (note the '80' should be '81')

Regards,
Sean McRobbie

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----- Original Message -----
From: "Fabian Arrotin" <fabian.arrotin@arrfab.net>
To: centos-mirror@centos.org
Sent: Tuesday, 15 July, 2014 7:05:18 AM
Subject: Re: [CentOS-mirror] [CentOS-mirror-announce] Important notification for the (upcoming) 7 release.

On 14/07/14 21:46, Robert Israel wrote:
  
Dear CentOS mirror administrators,

  I've inherited admin for centos.aol.com, and it appears we've run 
afoul of the block mentioned below, as we download from msync on a 
different IP than we serve out from.

  Per your instructions on this message, I'm responding to this list to 
request allowance of the following IP addresses...

205.188.84.37
205.188.84.38

  ...to rsync using the CentOS module.  For reference, below is the IP 
of our outgoing mirror VIP:

205.188.81.38

  If there's any questions/concerns, please let me know.

  Thanks!

 -Rob

    

Done and pushed ! (but your mirror VIP seems to be 205.188.80.38)

Verify that it now works.

Cheers,