Unable to mount network drive in Debian; error is "mount(2) system call failed: No route to host."

I've installed Debian 12, and I'm wanting to map/mount a network drive (hosted on a Synology NAS). I see no reason for the 'no route' error as I can ping the Synology server's DNS name and IP address. Both respond just fine. Furthermore, I also have a separate Ubuntu workstation where this same line in the */etc/fstab* works:

//myserver.local/mynetworkdrive/ /mnt/mynetworkdrive/ cifs auto,vers=2.0,credentials=/home/myusername/.smbcredentials,iocharset=utf8,noperm 0 0

Doing a

dmesg

returns this bit of information:

: No dialect specified on mount. Default has changed to a more secure dialect, SMB2.1 or later (e.g. SMB3.1.1), from CIFS (SMB1). To use the less secure SMB1 dialect to access old servers which do not support SMB3.1.1 (or even SMB3 or SMB2.1) specify vers=1.0 on mount.

: Unable to determine destination address

However, the solution to this message appears to be already taken care of with the 'vers=2.0' directive I have in the fstab file (I've tried changing the version numbers with no success). Suggestions for the next steps to help resolve?