Tor: same exact entry node since a week ago

Question

Since a few days ago, my copy of Tor (4.5.3) keeps using exactly the same entry node every single time I use it. I am pretty sure that that's not how it used to be in the past.

I feel a bit uncomfortable about it, so I wanted to ask for advice if it's just another security improvement that came with v4.5.3 or if I should do something about it?

The documentation states that it's normal for Tor to use only a few entry relays, and not just a single one. That's what made me suspicious: Tor has been showing me the same IP address for the entry relay for almost a week now.

Here's a bit more information on my situation: I am using Tor in a relatively small country with a population of less than 10 million people. According to Tor, the entry relay I have been using the past few days is also located in my country.

In the past, however, Tor mainly selected entry nodes located in adjacent countries (which are multiple times bigger in size and population and thus offer more nodes in general, I guess). I remember very rarely seeing Tor selecting any relays (be it entry, middle or exit) located in my country at all (as there are probably not many relays in my small country in general).

So all in all, I am not quite sure what to make of this recent change and how to react to it.

Before I start changing the default behaviour of Tor, I'd like to know why it's behaving like it is. Maybe Tor is only selecting that particular entry node, because all other entry nodes "in the vicinity" are compromised or something like that. Forcing Tor to select other entry nodes would be a bad choice in that case.

Answer 1

Do not panic, that is the normal behavior you could expect. It is designed that way. But why ? As mentioned in the documentation:

choosing many random entries and exits gives the user no chance of escaping profiling by this kind of attacker. The solution is "entry guards": each Tor client selects a few relays at random to use as entry points, and uses only those relays for her first hop.

That is why Tor uses only very few entry relays so that it protects you from using compromised ones.

Answer 2

Recent versions of Tor(>= 4.5) allow for specific entry/exit node selection. By adding the bellow entries to the ./Data/torrc:

EntryNodes {ru}
ExitNodes {ru}
StrictNodes 1

you can pick the countries/regions of your entry/exit nodes.