Hi, I'm trying to troubleshoot a problem I have with a Windows PC connecting to an Synology DS218J NAS on SMB2. I keep getting errors whether connecting via hostname or IP address directly, even when Windows Defender firewall is disabled. The NAS server is working fine as I can access its web portal from the same PC, and I can also access the SMB file shares with other mobile devices/laptops. I've tried looking at the SMB version settings (SMB2 is enabled on the NAS), and even did a Network Reset on the PC, but still no go, so I decided to delve deeper by looking at a packet capture.
What I see when I try to connect to the NAS on Windows Explorer, is the following: 1. TCP 3-way handshake ([SYN],[SYN,ACK],[ACK]) 2. Negotiate Protocol Request from PC to NAS 3. TCP ACK from NAS to PC 4. Negotiate Protocol Response from NAS to PC 5. [RST,ACK] from PC to NAS
Steps 1-5 will then repeat twice (total 3x) before ultimately failing.
What could be wrong here? Is it a TCP problem, an SMB problem or some other problem?
