NAT vs Bridged vs Host-Only Networking

I was explaining to one of my close friends the difference among NAT, Bridged and Host-only Networking often found in VM settings. I could make him understand that and then I thought why not writing it down for others. In fact, I had the same confusion before. Hope my explanation would help you understand the difference. Host-Only: Networking within the host OS. So, a VM will be assigned one IP, but it’s only accessible within the host OS where the... Read more

Configuring MikroTik QEMU VM in GNS3 with Winbox on Mac using TunTap

I didn’t have to work on MikroTik routers until now when most of our clients are Universities and it is needless to say how popular MikroTik boxes are to them. There would be no one without them. And, almost everyday we get calls from universities to provide technical supports by configuring or suggesting configurations for their MikroTik routers. Hence, I thought why not getting familiar with MT! Working with the new OS would be fun ­čÖé The very first time... Read more

Unable to negotiate with x.x.x.x port 22: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1

The Problem I just got an updated on my macOS Sierra to version┬á10.12.4 (16E195). Since then, my┬áSSH attempt gets rejected when connecting to our remote CISCO routers. Though, all were running fine before the update. Here’s the log I was getting: Awals-MacBook-Air:~ awal$ ssh awal@ Unable to negotiate with port 22: no matching key exchange method found. Their offer: diffie-hellman-group1-sha1 Reason macOS Sierra is rejecting that cipher type because it is very weak (reference:┬áImperfect Forward Secrecy: How Diffie-Hellman Fails... Read more

WordPress Upgrade Problem: /wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F

Gosh, I was disappointed while upgrading to WordPress 4.7 for my website. Here’s how I solved my problem… Problem: As soon as I updated WordPress to it’s latest version (v4.7) for my website, the browser just redirected me to /wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F. The browser actually showed nothing and I couldn’t login to my admin panel, Pic 1 shows the screenshot.   Solution:┬áI found mismatch between the db_version in Database and version.php in wp-includes. Here are the steps: Login to cPanel accessing your... Read more

SSH with private/public key authentication

Some of you, like me, might use Putty.exe as your SSH client in Windows operating system. Thankfully it has a tool called PUTTYGEN.EXE which in fact can generate private/public key for authentication. Here are the steps: 1. Double-click on puttygen.exe At the bottom of the dialog box, under “Parameters”: Make sure the type of key to generate is “SSH-2 RSA” Set the number of bits to 2048 2. Click on “Generate”. Move the mouse randomly over the blank area until... Read more

Facebook Messenger enables encrypted messaging

I was reading the news in Wired and happy that after waiting a long Facebook finally woke up for encryption in its Messenger App. Messenger is very popular in my country (Bangladesh) and I think most of the users here don’t bother about privacy or security or encrypted messaging. It that context, again I think Facebook has enough room to take proactive measures in order to respect the privacy of its wide level of user base. And, finally they did... Read more

Maximum execution time exceeded: C:\xampp\htdocs\testsite\wp-includes\Requests\Transport\cURL.php on line 463

I was playing with a demo site using WordPress in my localhost with XAMPP. At some point, while installing a plugin called The Events Calendar, the installation failed with the error message: Reading some articles to get a solution, I found people reported similar problems having a little different error messages, like: Fatal error: Maximum execution time of 30 seconds exceeded in C:\xampp\htdocs\tal\dev-2\wp-includes\class-wp-http-curl.php on line 324 Solution: This is neither a problem with the WordPress nor with the Plugin, it’s... Read more

[From APNIC Blog] Increasing IPv6 deployment in Bangladesh

Recently, Robbie Mitchell from APNIC published an interesting article about the IPv6 deployment status in Bangladesh. The blog post described quite a real picture of v6 deployment in the country including the challenges that we are facing here and the ways to overcome it. Two of the most popular faces in our community and of course my most favorite network professionals and mentors, Sumon Ahmed Sabir and Fakrul Alam Pappu put their valuable comments and views there. I got the... Read more

IPv6 Detector widget for WordPress

If you’re maintaining a WordPress site and are interested to use IP address detector widget, there is a simple plugin for that called IPv6 Detector. Thanks to the developer Andres Altamirano. Though he didn’t update it for a long time, yet it works absolutely fine. All you need is to install the plugin and add the widget in the widget area of your website. The original version of the plugin shows some additional information (see an example site here) which... Read more

IPv6 Deployment status in Bangladesh

11 April this year I had a chance to attend bdNOG5 and ION Conference 2016 which was held in Dhaka. It was quite a good crowd and I got the opportunity to present a case study on the IPv6 deployment status in Bangladesh. I would like to share the brief of my presentation here. Summarizing IPv6 history of the country So far, APNIC delegated more than 350 AS Numbers, about 550 IPv4 prefixes and nearly 150 IPv6 prefixes to different... Read more