This issue has been bugging me since last year. It started when I am still running Linux Mint, suddenly after an update, my wireless adapter stop working suddenly. I try to find a way to fix it on Google, but did not found any working solutions. Because I am quite busy at that time, I simply used USB tethering to get around it, and soon forget about the problem.

Early this year, I decided to try MX Linux because it seems to be more lightweight and stable (once a year release compared to monthly release which mean less crash) than Linux Mint. I did notice the performance is noticeably better, and I never have a crash or bug anymore after update, overall it is very stable, but the wireless adapter problem still persist, so clearly the problem is not the OS.

Tonight I remembered about the issue and because I am still curious about it, I decided to research about the issues again with a fresh approach. The first thing I do is running ` lsusb` command on the terminal after I connected my wireless adapter. This is the output:

![ lsusb output](https://xmyforsgwfqphgifjxpe.supabase.co/storage/v1/object/public/strapi-blog/strapi-blog/lsusb.png16bd855051b18e46f53d34ff8671297c.png)

Gotcha! I found the needed driver version for my wireless adapter which is `RTL8188EUS`. I then run `lsmod lsmod | grep 8188` to check whether the driver is loaded or not on the kernel, turn out it is not installed yet.

After a brief google search for the driver, I found it on https://github.com/aircrackng/rtl8188eus. I tried the instruction there, but sadly it still doesn't work. Suddenly I got an idea to try this command `echo "blacklist r8188eu" | sudo tee/etc/
modprobe.d/r8188eu. conf` and restart the computer. Finally, it's working! To spare you from wasting time like me, I will give you the precise step here:

1. Connect your wireless adapter
2. Open your terminal and run ` lsusb` to find your driver model, if it is not the same as mine, you can modify this tutorial by searching the driver model that match yours on Google and modify the last command to `echo "blacklist " | sudo tee/etc/modprobe.d/. conf`
3. Disconnect your wireless adapter and connect to internet with USB tethering from your phone
4. `sudo apt-get install mokutil && mokutil -- sb-state`, if it output ` SecureBoot disabled` you can proceed to the next step, otherwise you need to turn off the secure boot option from the BIOS because it can possibly interfere with the driver installation
5. `git clone https://github.com/aircrack-ng/rtl8188eus`
6. ` cd rtl8188eus`
7. `make && sudo make install`
8. `echo "blacklist r8188eu" | sudo tee/etc/ modprobe.d/r8188eu. conf`
9. Restart

I hope my article is useful to you, see you in the next article!

Fix TP-Link TL-WN722N Not Working on Linux

Imagine this scenario, you have 3 Github accounts, each have their own purposes. Account A for full time work, account B for portfolio projects and account C for personal projects. Whenever you are going to switch between repo in different accounts, you will need to use a different SSH keys for each account.

Changing SSH config every time you are switching is not good use of your time. Now you might start to think it is possible to have multiple SSH keys for each account and let SSH automatically manage it? Yeah, it is possible, but it can be quite tricky because there is a gotcha which I will explain further in this article.

I am assuming you are running Linux and already have openssh installed. For Mac you should be fine. For Windows you need to have git bash installed or WSL.

## Creating SSH keys
The first thing we need to do is to create a SSH key for each account.
Go to your terminal and run each command.

```bash
ssh-keygen -t rsa -f ~/.ssh/id_rsa_fulltime -C "fulltime@mail.com"
ssh-keygen -t rsa -f ~/.ssh/id_rsa_portfolio -C "portfolio@mail.com"
ssh-keygen -t rsa -f ~/.ssh/id_rsa_personal -C "personal@mail.com"
```

The first command is going to create a SSH key for full time account that are connected with the specified Github email: fulltime@mail.com and save it into the specified path: `~/.ssh/id_rsa_fulltime`.
The second and third commands do the same thing respectively for portfolio account and personal account.

## Adding SSH Keys Into SSH Authentication Agent

```bash
ssh-add ~/.ssh/id_rsa_fulltime
ssh-add ~/.ssh/id_rsa_portfolio
ssh-add ~/.ssh/id_rsa_personal
```

## Creating SSH Config File
Now you need to go to `~/.ssh` and create a file named `config` inside it.
Open it with vim or other text editor and add the following configurations.

```bash
Host *
AddKeysToAgent yes
IdentitiesOnly yes

Host github.com-fulltime
HostName github.com
IdentityFile ~/.ssh/id_rsa_fulltime

Host github.com-portfolio
HostName github.com
IdentityFile ~/.ssh/id_rsa_portfolio

Host github.com-personal
HostName github.com
IdentityFile ~/.ssh/id_rsa_personal
```

`Host *` means the config will be applied to every host, not only `github.com-prefix`.

`AddKeysToAgent` tells SSH to remember your password so you don't need to enter it everytime.

`IdentitiesOnly` is the gotcha I mean earlier. Let's say you are currently authenticated with fulltime account and you want to switch to personal account. If you did not specify it, **SSH will continue to use the first authenticated SSH key even though we have already specified different SSH key for each account**, in this case it will continue to use fulltime SSH key for each account.

The postfix (eg -personal) after `github.com` is used to identify different SSH keys, you can name it whatever you like but it should be unique, usually I named it the context in which the Github account is used for.

## Final Setup

If you already have an existing cloned repo from Github, you need to go the repo directory and edit `.git/config` file to append identifier postfix to the github.com hostname. For example you already clone a repo named `personal-project` from your personal account, to connect the correct SSH key to the repo you have to append this postfix `-personal` to the `github.com` hostname.

```bash
[remote "origin"]
url = git@github.com-personal:personal-account/personal-project.git
```

If you want to clone a new repo. Simply append the identifier postfix to the `github.com` hostname of the clone url.
`git clone git@github.com-personal:personal-account/personal-project.git`

After that, you will need to setup Github username and email for the repo.

```bash
git config user.name "personal-account"
git config user.email "personal@mail.com"
```

Congratulations, you have successfully setup multiple SSH keys.
See you in the next article!

2022