Duplicate first packet detected!

[tsaxelin]

Hi,

We're running a 3005 concentrator with 3.0.3 software and 3.0.2 client software. Most of the time everything works fine, but occasionally we get "Duplicate first packet detected!" in the Event log. What could cause this (other than an actual duplicate packet)?

[s-doyle]

I notice that in the log once in awhile too. I would suspect the client never got a SYN ACK back from the concentrator (or it was delayed) and re-sent the SYN. Doesn’t seem to be adversely affecting anything with our connectivity. Are you having trouble?

[srg]

I was getting this same error when the vpn client was on a computer running a personal firewall. After the client sent the IKE request, the concentrator would send a response, but the response was blocked and the client never received it. The client would send the request again, resulting in the "duplicate first packet" message in the log on the concentrator.