docker port mapping doesn't work

I’m confused - I have Docker file which use as “FROM” image. It’s very fast way to build vnc container with gui and chromium what is require by my project. And everything is fine but i have problem with port mapping - i want to run few similar containers on same server so it’s obvious that each container must use different port. I assumed that the easiest way will be run as below:

docker run -p 5902:5901 -t cont1
docker run -p 5903:5901 -t cont2
docker run -p 5904:5901 -t cont3
docker run -p 5905:5901 -t cont4

but when i try to connect via vnc, the connection can by established only with 5901 port - despite the fact that i use -p with mapping. Maybe someone will know what’s wrong?

hm… how are you connecting to the containers?

u have to tell vnc to use localhost:5902 … etc…

not the container IP, cause they are all only using 5901