Monthly Archives: September 2012

Windows Server 2008 R2 FTP is working internally but not through a Firewall

I ran into a problem today where a Server 2008 R2 FTP Server was working fine internally, but when you tried to access it from the internet it would not work. I checked the firewall rules, in this case a Sonicwall NSA, and the NAT and firewall rules were created properly, and they were passing traffic, but the connection was still failing.

The problem appears to be on the windows firewall, for some reasons the traffic is not making it through the windows firewall. Here is how we resolved the problem:

  1. Create a new Firewall in the Windows Firewall
  2. Allow a Program through the firewall, c:\windows\system32\svchost.exe
  3. Allow this rule for all traffic types, Public, Domain, Private
  4. Give the rule a name and click Finish.
  5. Now test again externally and you should be able to access the FTP site.

Configure Stacking and update firmware on Dell 55xx Series Switches

Here is a quick and dirty guide to getting a Dell 55xx switch stack up and running and get the firmware updated across the stack.

  1. First download the most recent firmware and a TFTP server, then start the TFTP server and extract the firmware files into the TFTP server’s directory.
  2. Plug in your HDMI stack cables into each switch(configure in such a way that they switches form a circle)
  3. Once the HDMI cables are plugged in, plug in to the console and power up the first switch. You’ll have to use hyper terminal, putty, teraterm, or some other console tool to run the initial wizard. Please set the IP address of the switch and when it’s completed you can power up the second(and 3rd,4th, etc) in the stack.
  4. Set the Master switch by using the following command: stack master unit 1
  5. Upload the firmware to each unit in the stack with the following command: copy tftp://z.z.z.z/powerconnect_55xx-yyyy.ros unit://*/image replacing the z.z.z.z and yyyy values with the IP address of the TFTP server and the version of the firmware you downloaded.
  6. Upload the boot code to each unit in the stack with the following command: copy tftp://z.z.z.z/powerconnect_55xx_boot-yyyyy.rfb unit://*/boot replacing the z.z.z.z and yyyyy values with the IP address of the TFTP server and the version of the firmware you downloaded.
  7. After the boot files and firmware have been uploaded you can issue the following command to check with image location it was placed in: show bootvar
  8. Finally once you know which image location it’s in, you can issue this command to boot from that firmware: boot system image-2 all, assuming your firmware was placed in image location 2 in the “show bootvar” output.