Any idea why I would be seeing Error:PingCollisionDetected in my IIS logs. IPv4 and IPv6 addresses are all diferent? 2013-02-26 23:29:04 10.1.1.3 POST /Microsoft-Server-ActiveSync/default.eas User=josh&DeviceId=ApplC34K1CKSDBGT&DeviceType=iPhone&Cmd=Ping&Log=V141_ Fid:10_Sk:1832614138_Sst3_SsCmt3_BR1_BPR0_Fid:24_Sk:485087893_Sst1_SsCmt1_BR1_BPR0_ Fid:2_Sk:761522165_Sst6_Sslc4_BR1_BPR0_LdapC1_LdapL16_RpcC42_RpcL78_Hb600_Erq1_Pk289512450_S3_ Error:PingCollisionDetected_Mbx:MBX002.domain.local_Throttle0_Budget:(A)Conn%3a1%2cHangingConn%3a0%2cAD%3a%24null%2f%24null%2f0%25%2cCAS%3a%24null%2f%24null%2f0%25%2cAB%3a%24null%2f%24null%2f0%25%2cRPC%3a%24null%2f%24null%2f0%25%2cFC%3a1000%2f0%2cPolicy%3aDefaultThrottlingPolicy%5Fbda8c676-952f-492d-bc9d-d740c69c81f7%2cNorm_ 443 domain\josh 10.20.100.2 Apple-iPhone5C2/1001.551 200 0 0 304546

Hi Josh, Based on my research, this Shouldn't be an issue it just means that we had pings that crossed paths - one was returning while another was being issued. This is simply a ping request sent by the device when we already have a subscription configured. If there is no problem when users connect via Activesync device, we may safely ignore it. You may download a analysis tool Log Parser Studio for further research. Refer to: http://blogs.technet.com/b/exchange/archive/2012/03/07/introducing-log-parser-studio.aspx http://blogs.technet.com/b/exchange/archive/2008/09/05/3406212.aspx Hope it is helpful. Fiona Liao TechNet Community Support

I thought it was from the other end. I was just double checking after the iOS6.1 issues just being a little paranoid thats all :)