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Cisco Bug: CSCuj17513 - Missing packets observed in AnyConnect virtual adapter with SSL

Last Modified

Mar 15, 2016

Products (1)

  • Cisco AnyConnect Secure Mobility Client

Known Affected Releases

2.5(2006) 3.1(3101)

Description (partial)

Slow throughput of AnyConnect Windows/Mac clients w/SSL compared to IPSec.  Further investigation shows that we are seeing missing packets in the Anyconnect Client Virtual Adapter when using SSL.

The SVC_UDP flow control drop can be reduced/eliminated using the following debugs on the ASA:

debug menu webvpn 123 1
debug menu webvpn 121 3 128 128
debug menu webvpn 121 5 1 1

Customer reported (with the above debug) that it still takes twice as long to download a 25M byte file using DTLS comparing with IPSec.

It turns out that there are missing FTP packets when looking at the client's virtual adapter captures.
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