Solution for Tower Cube (3x3x4) and Rex (8-axis) Cube

The solutions herein come from Internet, and their copyright belongs to respective (original) author(s).

Solution for Tower Cube (3x3x4):

Re-blog from http://solutions.spacebrew.com/tower/ (Original URL is invalid now.)

Phase 1: Solve the top and bottom layer corners.

1. First put the corners in their correct layer. To correct the final corners, hold the puzzle so that the incorrect cubies are at UFR and DFL, then perform:
   R D R
2. Now examine the side colors of the top layer corners to see which cubies need to be swapped to make the sides match. At most one pair needs to be swapped.
3. To swap adjacent corners, put the corners at the UFL and UFR, and perform:
   F U' F U F  ·  R U R U' R
4. To swap diagonal corners, put the corners at the UFR and UBL, and perform:
   R U² F U R U²  ·  F U' R U² F
5. The top layer corners should now be solved. Turn over the puzzle and repeat.

Phase 2: Solve the top and bottom layer edges.

1. First put the edges in their correct layer. Put unsolved cubies in UFM and DFM, and perform:
   U² R F R U² R F R
2. Repeat step 1 until all the edges are in their correct layers.
3. Now examine the side colors of the top layer edges to see which cubies need to be swapped to make the sides match the corners.
4. To swap adjacent edges, put the edges at the front and the right, and perform:
   R D B  ·  R U² R U² R U²  ·  B D' R
5. To swap opposite edges, put the edges at the front and the back, and perform:
   R U² R U² R
6. Repeat until the top layer edges are be solved.
7. Turn over the puzzle and repeat.

Phase 3: Solve the middle layer edges.

1. First put the edges in their correct layer. Put bad u edge at FR and bad d edge at FL, and then perform:
   R d R
2. Repeat step 1 until all the edges are in their correct layers.
3. Turn u to put at least two of its edges correct. At most one pair needs to be swapped.
4. To swap adjacent edges, put the bad edges at FR and FL and perform:
   u' R u R  ·  d' R d R  ·  F d F
5. To swap diagonal edges, put the bad edges at FR and BL and perform:
   R u² F u' R  ·  u d R d' F u² R u'
6. The u layer edges should now be solved. Turn over the puzzle and repeat for the d layer.

Phase 4: Solve the middle layer centers.

1. Perform one of the following to swap two cubies:
• To swap Bu and Lu, perform: R F L d L F R u


• To swap Bd and Ld, perform: R F L u L F R d


• To swap Bd and Lu, perform: u R F L d L F R


• To swap Bu and Ld, perform: d R F L u L F R


• To swap Bu and Fu, perform: R F L d² L F R u²


• To swap Bd and Fd, perform: R F L u² L F R d²


• To swap Bd and Fu, perform: u² R F L d² L F R


• To swap Bu and Fd, perform: d² R F L u² L F R
2. Repeat until the centers are all solved.

Solution for Rex Cube (Video):

First, Solve Dino Cude

https://www.youtube.com/watch?v=noAQfWqlMbk

Second, Solve Rex Cude

https://www.youtube.com/watch?v=noAQfWqlMbk

How to perform a TCP ping

Normal ping using ICMP, not TCP nor UDP.

But sometimes we want to check whether a port is open or not.
For example I establish a new service on my server but find out client cannot get access.
That's time when we should use TCP ping.

So how can we perform TCP ping?

If you are using Windows, you can use tcping, a simple CLI tool brought to you by Eli Fulkerson, which can be downloaded here.

If you are using Linux, then you have multiple useful choices.
The first is nmap.You can use it like this

nmap -p 80 onofri.org

The second is tcpping brought to you by Richard. Click here for tutorial.
There are some other tool can perform TCP ping too, e.g. Hping, Paping.

If you'd prefer web application, there are many websites that offer a bunch of Network tesing tool such as ping, tcping, tracert, etc. Just Google it.