All Barracuda Web Filters / WSGs, all firmware versions.
· Many times an ISP problem exists with their modem or upstream of your network.
· There is a concern that it could be related to your Firewall
· It could be something with any perimeter devices like IDS / IPS
· Even mention of load balancers, DOS and NAT boxes.
Basically the issue is seen as a request was sent out from the filter, upon returning to the filter it was seen as a Zero Sized Reply packet. This was not the web filter stating it has a problem, it is a reply the Web filter acknowledged from a bad packet returned to it.
Many times the ISP will be able to track down where the issue is and help to resolve the problem experienced.
See article here, on Zero sized possible fixes
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