It is really easy. I even managed to upgrade a FreeBSD 7.0 machine up to 12 remotely. Major upgrades (for example 10.x to 11.y) are more complicated because it requires updating all ports and software as well. Minor upgrades (like in your case) are "peace of cake" and it's all about one restart.
Assuming that you are not with custom kernel and stuff like that, the upgrades are done with the utility "freebsd-update". What you must do is:
Code:
freebsd-update upgrade -r 11.3-RELEASE
It will loop through lots of checks and will ask you if you want to continue (it will list you what it will do and will ask you if it "looks reasonable"). After that it will fetch a long list of patches - few thousands to be more precise. It takes some time.
Next there may be some minor issues with some default configuration files - if the utility finds such, it will ask you to open them in the editor "vi". Inside such files it will list to you what the current situation inside the file is and what the new default is supposed to be. Read carefully there and delete whatever is not needed (whole line delete is "dd"). Save the file and quit with ":wq"
When you are ready it will exit and it will be ready to install. To install it make:
Wait for it... and when it says that it's done, you must reboot the machine:
When you login again, do again:
And you are done. That's it.
I updated two different servers lots of times. Never had any issues.
P.S. If you are not using the OpenSSL from base but the one from ports, you have no worries. Usually that's the case because the DA installation recommends doing that. You can check that in /etc/make.conf. If you use OpenSSL from ports, then you will have there:
Code:
DEFAULT_VERSIONS+=ssl=openssl
If you are unsure, you can rebuild the ports and DA packages that depend on OpenSSL too. Usually this is NOT needed when doing minor upgrades but sometimes people do it "just in case", because minor upgrades also update the base OpenSSL to newer version (it's still a minor OpenSSL upgrade, not a major one, so rebuilding is not really necessarily).