R6400V2 failed firmware

> [...] what appears to be a cycle [...]

   In some cases, the router can get into a (failing) boot loop, which
might mean that if it's ever receptive to a TFTP load, then you might
need to catch it at the right time.  Some experimentation may be needed.

> [...] (see attached).

   You're running the "tftp" program, and then giving _it_ a command to
run the "tftp" program.

> [...] But the "$" int he above is what confuses me.

   What was on the line before what you posted?  That "$" was supposed
to represent (abbreviated) the prompt from your shell (which, as your
"ping" picture showed, is pretty long, but does end in "$ ").

   So, the actual command should look like:

      <blah-blah-blah> $ tftp 192.168.1.1

of which you type only: tftp 192.168.1.1

   The "tftp" program uses a "tftp> " prompt, and you type whatever
appears after that in the example.

> [...] I'm sorry, I'm a bit novice at this. [...]

   I noticed.  Just bask in the education.  Wheee.

> [...] I already did the /usr/bin/tftp bit to access the tftp.

   That was what the "tftp 192.168.1.1" command was for.  You could,
instead, do:

      $ tftp
      tftp> connect 192.168.1.1

which would be equivalent to (but more work than):

      $ tftp 192.168.1.1

   The "put fred.img" command assumes that your firmware image file (use
its actual name) is in the shell's current directory.  Otherwise, you'd
need to specify an appropriate path to it (like the one (partially)
shown in your Tftpd64 screen shot, but with a Mac/unix syntax instead of
a PC\Windows syntax).  For some shell navigation basics, see, for
example:

      https://community.netgear.com/t5/x/x/m-p/1694410