After a couple of days of struggling to understand why my laptop was the only one that couldn’t open a connection to a network resource. I finally found out that it was a mac address mix-up.
Sometime ago while testing I used my laptop to pretend that it was that resource. To do that the laptop had its physical address changed. Since then I have forgotten to change the mac address back.
Today I tried traceroute and got surprised. The resource is a couple of hops away, but traceroute said it’s right next to me. I should have noticed that since the machine was responding to a ping 10 times faster than before.