Microtic devices have a huge range of functionalities, but there are various strange and inexplicable limitations, which can make you wonder for a long time “WHY?”. It is a similar restriction, that only IP addresses for NTP servers can be placed in the dhcp pool settings, to be distributed to customers but not hosts. If we want to use a server from ntp pool and to distribute it to customers behind microtics we have a serious problem – or we need to put IP addresses from the ntp pool project, as they are currently being resolved, but we have no guarantee, that they will continue to work for the future or we have to think of another scheme. I decided to be either…

The Microtic OS offers the ability to writing scripts. I can not say, that I am an expert there, but I don't mind using it, when i need. We will briefly create a script, which resolves 4 The NTP server and then configure our dhcp pool with them. The script is quite simple:

:local s0 [resolve bg.pool.ntp.org]
:local s1 [resolve bg.pool.ntp.org]
:local s2 [resolve bg.pool.ntp.org]
:local s3 [resolve bg.pool.ntp.org]

/ip dhcp-server network set ntp-server="$s0,$s1,$s2,$s3" numbers=0

Then all we have to do is make the script run once a week, say – at least for me this is a very reasonable period and that, that I have 4 the NTP address is safe enough even if one of them stops working:

/system scheduler
add interval=1w name=ntpSet policy=\
    read,write,policy \
    start-date=nov/02/2020 start-time=20:17:14

Lately I read a lot of things that are not typical for me, these are the pleasant ones…. (this is from before over 1 year)

This one is dying slowly…
who does not travel,
who does not read
and does not listen to music,
which does not detect
charm in itself.

This one is dying slowly…
which destroys
your selfishness,
who refuses help,
who is not looking for diversity.

This one is dying slowly…
which turns
in the slave of habit,
passing every day
on the same paths,
who does not risk
to dress in a different color
and does not talk to strangers.

This one is dying slowly…
who flees from passion
and the vortex of feelings,
which restore the sparkle in the eyes
and save sad hearts.

This one is dying slowly…
who does not change his life,
when he is dissatisfied with the work
or your love,
which does not risk security
for the unknown,
to pursue a dream,
who does not decide at least once in his life
to escape the wise counsels.

Don't die slowly… live today!

Take a risk today! Act today!

Don't let yourself die slowly!

Don't forget to be happy!

It's been rolling over the past weekend TuxCon 2017. Most people think I've done pretty well with my lecture. Personally, I'm not entirely happy, there are definitely a lot of things to work on, because I plan not to have my last such event in the future. If I have to be honest about most of the presentation, I hardly remember it, it was like a trance. I remember sporadic moments when I look at my watch and find out, that a decent amount of time has elapsed.

It was definitely not easy, even with that in mind, that the audience was extremely narrowly focused and there was no big barrier with the audience.


DN42 is a wonderful project that allows you to develop your BGP skills without breaking the product environment, without having to have expensive devices to make a lab to do simulations with GNS3. At the same time, it should not be a purely laboratory environment in which there are no real-world problems. I participate with 1 node in the project for about a year. One of the problems in the project is 1:1 with the real world – when someone announces prefixes that they shouldn't announce. Because I'm lazy and I don't write filters by hand all the time, I solved the problem with an elementary bash script that generates a prefix-list named dn42 and I pour the valid prefixes in it.

vtysh -c 'conf t' -c "no ip prefix-list dn42"; #drop old prefix list

while read pl
vtysh -c 'conf t' -c "$pl"; #insert prefix list row by row
done < <(curl -s https://ca.dn42.us/reg/filter.txt | grep -e ^[0-9] | awk '{ print "ip prefix-list dn42 seq " $1 " " $2 " " $3 " ge " $4 " le " $5}' | sed "s_/\([0-9]\+\) ge \1_/\1_g;s_/\([0-9]\+\) le \1_/\1_g");
vtysh -c 'wr' #write new prefix list

The list of valid prefixes is taken https://ca.dn42.us/reg/filter.txt from where the main pipeline + a few modifications on my part to be able to generate prefix sheets. Commands are executed through vtysh.

For the 4th consecutive year, the conference on free software and hardware will be held TuxCon. Personally for me this is the strongest Plovdiv conference that is being held, as it is not only aimed at developers, and the target group is much larger and the audience is very colorful. If my memory serves me right, I don't think so, that I have missed an edition so far. This annual edition is especially for me, since I have a presentation. I will talk about dnsdist and whether it is useful for your infrastructure. I chose the topic I will talk about myself. I felt the need to show it to the world, as she is relatively young, and so far I have hardly found anything in it that I do not like. I don't remember the last time I was so impressed by something new and working extremely well at the same time.