Saturday, June 22, 2019

IPSec VPN Configuration on Ubuntu 18.04

This was something I had to do repeatedly on all my Linux laptops. I found that you must follow *both* 2 articles listed below in the same order, to get it working!




The package to install in Ubuntu 18.04 can be found here.

Sunday, May 19, 2019

Thermald and MCE error

I randomly kept getting the below errors in my Centos laptop. I installed thermald. It seems the error is fixed for now. Let's see. :)

Message from syslogd@llovizna-lenovo at Apr 17 14:29:02 ...
 kernel:mce: [Hardware Error]: CPU 0: Machine Check: 0 Bank 5: ee0000000040110a

Message from syslogd@llovizna-lenovo at Apr 17 14:29:02 ...
 kernel:mce: [Hardware Error]: TSC 0 ADDR fef81fc0 MISC 78a0000086

Message from syslogd@llovizna-lenovo at Apr 17 14:29:02 ...
 kernel:mce: [Hardware Error]: PROCESSOR 0:40651 TIME 1555525734 SOCKET 0 APIC 0 microcode 24

Message from syslogd@llovizna-lenovo at Apr 17 14:29:02 ...
 kernel:mce: [Hardware Error]: CPU 0: Machine Check: 0 Bank 6: ee0000000040110a

Message from syslogd@llovizna-lenovo at Apr 17 14:29:02 ...
 kernel:mce: [Hardware Error]: TSC 0 ADDR fef82100 MISC 78a0000086

Message from syslogd@llovizna-lenovo at Apr 17 14:29:02 ...
 kernel:mce: [Hardware Error]: PROCESSOR 0:40651 TIME 1555525734 SOCKET 0 APIC 0 microcode 24







$  dmesg | grep -i 'mce:'
[    0.023131] mce: CPU supports 7 MCE banks
[    1.037974] mce: [Hardware Error]: CPU 0: Machine Check: 0 Bank 6: ae0000000040110a
[    1.038009] mce: [Hardware Error]: TSC 0 ADDR fef87380 MISC 278a0000086
[    1.038033] mce: [Hardware Error]: PROCESSOR 0:40651 TIME 1555486489 SOCKET 0 APIC 0 microcode 24
[  300.672620] mce: [Hardware Error]: Machine check events logged
[24841.300647] mce: [Hardware Error]: Machine check events logged
[24841.300730] mce: [Hardware Error]: CPU 0: Machine Check: 0 Bank 5: ee0000000040110a
[24841.300735] mce: [Hardware Error]: TSC 0 ADDR fef81fc0 MISC 78a0000086
[24841.300739] mce: [Hardware Error]: PROCESSOR 0:40651 TIME 1555525734 SOCKET 0 APIC 0 microcode 24
[24841.300743] mce: [Hardware Error]: CPU 0: Machine Check: 0 Bank 6: ee0000000040110a
[24841.300747] mce: [Hardware Error]: TSC 0 ADDR fef82100 MISC 78a0000086
[24841.300750] mce: [Hardware Error]: PROCESSOR 0:40651 TIME 1555525734 SOCKET 0 APIC 0 microcode 24


Thursday, May 9, 2019

Hosting a RIPE ATLAS Probe in Atlanta

My RIPE ATLAS Probe
I used RIPE Atlas for my Internet measurements in my IFIP Networking 2018 paper (NetUber: A cloud-assisted overlay network as an alternative connectivity provider) and consequently my thesis. I consumed the RIPE Atlas credits from my co-author for those experiments. Afterward, I requested RIPE to send me a probe, and now I have received it! I have connected it to my home router. My probe is currently connected to the RIPE Atlas network and started receiving traffic. I am happy to contribute back to the Internet measurements community!

Saturday, May 4, 2019

My EMJD-DC Erasmus Mundus Journey

View from my apartment in Rijeka, Croatia
My Ph.D. started 19 days before my MSc. defense. :) I got the happy news that I had received the Category "A" EMJD-DC Erasmus Mundus Scholarship, while I was attending the EMDC Winter Event in Evora. I started with IST, ULisboa, Portugal, as my first university. I continued with my MSc supervisor as my Ph.D. advisor also, as he is really a great supervisor and mentor.

Following my MSc defense, my Ph.D. started smoothly. I finished all my course requirements for the first year. I also went to the University of Rijeka, Croatia, for a short-term scientific mission (STSM). It was fun, spending the summer in Rijeka. I also had the chance to visit nearby countries (Italy, Slovenia, and Serbia) by bus, for a very low price. On the other hand, my stay in Croatia was also very productive. My research work there became a core of my thesis.

Night walk from KAUST
I did 2 Google Summer of Code (GSoC) from Portugal. Once during my MSc (2014) and the other during my Ph.D. (2015). I also did an OpenDaylight internship. Then I moved to Atlanta for 7 months for an extended internship at Emory University, as a continuation of my GSoCs. When I returned from Atlanta to Lisbon, I had to apply for the Belgium visa quick since I was already in my third year and I must move to my second university (UCLouvain) in Belgium. After a short period of 4 months in Lisboa, we moved to Louvain-la-Neuve, Belgium in February 2017. Later in 2017, I also spent 2 months in KAUST, Saudi Arabia, the 5th university of my Ph.D. Finally, I returned to Portugal for my 4th-year 2nd semester, December 2017. In the next 6 months, I made sure to satisfy all the thesis requirements of IST and UCLouvain, including the UCLouvain Thesis Confirmation and IST CAT. I also finished the thesis draft and moved to Emory University again before the defense. 

Evora, Portugal
There are a few things I could have done better. For instance, looking back, I feel I should have defended the thesis before moving out of the EU. It was just defense pending, and moving away from the EU made the process much longer. Similarly, I also think I should have started writing the thesis early on, making sure the LaTex variables across my various papers do not have naming conflicts. That would have helped me when I consolidated the content from my various papers to the thesis document. But I am still happy with how everything went. Next is to defend my thesis in 2019 July. I am looking forward to it.

Sunday, April 14, 2019

My EMDC Erasmus Mundus Journey

KTH Welcome Reception at Stockholm City Hall, 2013
7 years ago in 2012 August, I arrived in Lisbon for my Erasmus Mundus masters program, European Master in Distributed Computing (EMDC). My mobility was, IST (Lisboa, Portugal) -> KTH (Stockholm, Sweden). My first academic year should be in Portugal and the third semester (first half of the second academic year) should be in Sweden. The final semester is the thesis, and it was proposed that it should be in KTH, Sweden, although it was not set in stone, unlike the first 3 semesters.

KTH Main Campus in Summer
Initially, my grant was in a waiting list, and I was careful with the money. But I was approved for the full scholarship, Category "A" soon after. This eliminated my worry about money. I had planned to spend just one year in Portugal and the second year in Sweden. However, I decided to come back to IST for my final semester for my master thesis.

The first semester was interesting. Everything was new. We had a group of international students doing our Erasmus Mundus program. We all were always together. We also had other international students from various other mobility programs.

KTH Main Campus in Autumn
Portugal was my 4th country to visit. Lisbon was my second city in Europe. My first trip was in 2010 to Paris. Of course, at first, Lisbon felt underwhelming compared to my expectations based on Paris. However, it became a positive experience quickly. We had 2 out of the 4 courses of the first semester in Taguspark. We would take the IST shuttle in the morning to commute to Taguspark campus from the Alameda campus. My apartment was in a walking distance to the Alameda campus where we had most of the lectures. We often had meals in the canteen - the Taguspark canteen was much better than the ones in Alameda. We also had a winter event in Nuria, Spain in the snowy mountains. We enjoyed the snow and the -11℃.

View of the Langholmen island, Stockholm
Our move to Stockholm was smooth. We had more students in KTH/Sweden in our group compared to IST/Portugal, as all the students of EMDC had to spend one semester in KTH. While we spent our first year in IST, Portugal, the other half of us had spent their time in UPC, Barcelona, Spain. Stockholm was fun. It had lots of lakes and forests. Its metro stations were beautiful. It also had a popular story involving a discontinued metro station, Kymlinge, and an old Silverpilen (silver arrow), the Ghost Train. Summer was long and comfortable. Winter was depressingly dark. But inside our apartment, it was warm enough. Unlike Lisboa, Stockholm had a good central heating.

EMDC Summer Event in Fejan
For the final semester, I decided to come back to IST for the master thesis. Everyone else either stayed at KTH or went on to different companies or research labs. So I was back to INESC-ID Lisboa. But my experience was entirely different from 2012 and 2013 when I had a big group. Anyway, I successfully completed EMDC, with a score of 18/20 for the master thesis, with 2 publications (at MASCOTS and UCC). I also worked at UniPlaces as a part-time software engineer by the end of the 3rd semester to early 4th semester.

Gamla Stan
Masters in Europe, specifically the Erasmus Mundus mobility programs, are very exciting. I decided to continue my higher education in Europe with Erasmus Mundus. I applied for EMJD-DC (Erasmus Mundus Joint Doctorate in Distributed Computing) and got selected with the category A scholarship. Finally, my EMDC came to a successful end.

We also had 2 graduation ceremonies. One for KTH at the Stockholm city hall where they usually present the Nobel awards! We also had our welcome reception in the city hall when we arrived in Stockholm. Most of us had a reunion there meeting our friends after a long time during the KTH graduation ceremony. We also had a graduation ceremony at IST. But unfortunately, it was only me who was attending. Luckily, I was staying in Lisboa for my EMJD-DC at that time. Overall, EMDC left me with very happy memories and no regrets! Given a chance, I would not do anything different. :)