VPN connection dropped / First packet isn’t SYN

Dyslexic155 — Mon, 12 Oct 2020 12:28:44 GMT

Hello Experts,

We were running on R80.20, but after we upgraded to R80.30 T217 we experienced a behavior that didn't happen before.

The sitiation was that we were able to initiate the SSLVPN connection, but every 7 minutes or so, the connection broke and the TCP stack had to re-initiate.

During this re-initiation, the VPN connection is dropped for 10 – 30 seconds, though in most cases, it got re-established without having to re-authenticate to the VPN. It was as if the firewall apparently “forgets” certain sessions related to SSLVPN, at
which point the connection is no longer known in the session table and the traffic is dropped. (First packet isn’t SYN).

A failover solved the issue, and it didn't happen again.

So is there a known bug the reason for this behavior in T217? As I believe it's not related to a configuration thing as just the failover solved the issue and till now it didn't happen again.

We need to make sure it doesn't re-occur.

Best Regards,

Re: VPN connection dropped / First packet isn’t SYN

PhoneBoy — Mon, 12 Oct 2020 18:18:35 GMT

I would get the TAC involved, especially if this worked without issue in R80.20.

topic VPN connection dropped / First packet isn’t SYN in Firewall and Security Management

VPN connection dropped / First packet isn’t SYN

Re: VPN connection dropped / First packet isn’t SYN