Flashing a SnapGear box

Product:
SnapGear VPN router

Type of Product:
Hardware

OS:
Mac OS X

Issue: SnapGear doesn't provide an easy firmware update utility for Macs

Solution: Use the tftp server built into OS X

Details:
Upgrading the firmware in a SnapGear requires a TFTP server for the SnapGear to pull from. OS X happens to provide such a server, but not an interface to enable it. Here's the procedure:

Enable the TFTP server. Under OS X 10.2 this can be done with either inetd or xinetd; xinetd is better in general, but inet's a bit easier to set up so we'll use that. Edit the file /etc/inetd.conf and remove the comment marker ("#") from the TFTP line. I.e. change this:

   #comsat dgram   udp     wait    root    /usr/libexec/tcpd               comsat
   #tftp   dgram   udp     wait    nobody  /usr/libexec/tcpd               tftpd /private/tftpboot
   #bootps dgram   udp     wait    root    /usr/libexec/tcpd               bootpd

Into this:

   #comsat dgram   udp     wait    root    /usr/libexec/tcpd               comsat
   tftp    dgram   udp     wait    nobody  /usr/libexec/tcpd               tftpd /private/tftpboot
   #bootps dgram   udp     wait    root    /usr/libexec/tcpd               bootpd

As for how to do the edit? You'll need root access, so it's easiest to use a command line editor with the sudo command.

Create a TFTPable directory. Use the command:
```
   sudo mkdir -m 777 /private/tftpboot
```
(Note: this creates the tftp directory with wide-open permissions. Ok for temporary use, but should be changed if you're going to leave the TFTP server running very long.)
Activate the new inet settings with the command:
```
   sudo killall -HUP inetd
```
(this basically sends the inetd daemon a signal to reload its configuration.)
Put the firmware binary image file in the TFTP directory. Use the Finder's Go To Folder menu option to go to /private/tftpboot, and copy/move the image there.
Back up the SnapGear's configuration. Open a browser and connect to the SnapGear's web management interface; go to the System:Advanced screen, and look in the Configuration Files section. You should see an option to Save/Restore all configuration files remotely (not to be confused with the "Save and Restore" option which backs the config up on the SnapGear itself). Follow the Save/Restore link, and copy the resulting config dump to a text file on your Mac.
Go back to the System:Advanced screen, and click on the Flash Upgrade link.
Fill in the IP address of your Macintosh, and for Filename put the complete path to the image file (it should be something like "/private/tftpboot/SnapGearPRO_v1.8.4_20030825_imagez.bin"). Leave the Extra Parameters field blank, and click Update. You may also need to confirm the update on the next screen.
DO NOT turn off the SnapGear unit during the upgrade procedure. Just give it a minute to upgrade itself and reboot, then refresh its web admin. Go to the System:Diagnostics to confirm the new firmware version.
Once the upgrade is done, turn off the TFTP server by editing /etc/inetd.conf back the way it was, then doing the
```
   sudo killall -HUP inetd
```
command again.

Some Related Information...

SnapGear Firmware Downloads
This Document Prepared By Gordon Davisson on 10/9/03

Reference

Flashing a SnapGear box

Some Related Information...