https://kb.fortinet.com/kb/documentLink.do?externalID=FD33101 The ESP packet invalid error is due to an encryption key mismatch after a VPN tunnel has been established. When an IPSec VPN tunnel is up, but traffic is not able to pass through the tunnel, Wireshark (or an equivalent program) can be used to determine whether there is an encryption mismatch. A mismatch could occur for many reasons, one of the most common is the instability of an ISP link (ADSL, Cable), or it could effectively be any device in the physical connection. The following information is required to troubleshoot the problem. 1) Take a packet sniffer trace on both FortiGates. 2) Run the "diag vpn tunnel list” command a few times on both FortiGates when generating traffic that will pass through the tunnel. In the following example, the error message was seen on the recipient FortiGate: date=2010-12-28 time=18:19:35 devname=Kosad_VPN device_id=FG300B3910600118 log_id=0101037132 type=event subtype=ipsec pri=critica...
Step 1: Creating Internal NAT Virtual Switch: To create NAT switch, we need to run the below command on Windows Administrator PowerShell and check the status. PS C:\> New-VMSwitch -Name NATSWITCH -SwitchType Internal After running the command you will get the display shown below. Run the Get-NetAdapter command to get the ifindex (connected interface) and Virtual Switch details. Step 2: Run the below command to configure NAT Gateway IP. PS C:\> New-NetIPAddress –IPAddress 192.168.103.185 -PrefixLength 24 -InterfaceIndex 14 For above command: NAT Switch IP Address is: 192.168.103.185(NAT GATEWAY IP) Prefix Length: 24 (Subnet mask) Interface Index: 14 Connected interfaces (See above screenshot for interfaces) After running this command and it displays the required brief details, refer below screenshot. Step3: Now run the below command in order to configure NAT Network. To assign NAT IP segment(192.168.103.0/24), we have to use Host Machine VMs. PS C:\> New-NetNat -Name NATS...