pmm2.1 - pmm-agent listening two ports ?

I only completed the pmm-client installation with rpm and did not configure pmm-admin.

Why are there two ports listening on the pmm-agent?

/usr/local/percona/pmm2/config/pmm-agent.yaml

listen-port: 7777
~~
~~
ports:
min: 42000
max: 42010

netstat -lnpt |grep pmm-agent

tcp 0 0 127.0.0.1:7777 0.0.0.0:* LISTEN 9786/pmm-agent
tcp 0 0 127.0.0.1:[COLOR=#FF0000]35355 0.0.0.0:* LISTEN 9786/pmm-agent

service pmm-agent restart

netstat -lnpt |grep pmm-agent

tcp 0 0 127.0.0.1:7777 0.0.0.0:* LISTEN 9786/pmm-agent
tcp 0 0 127.0.0.1:36951 0.0.0.0:* LISTEN 9786/pmm-agent

What is this port changed in pmm-agent?

And is there a parameter to lock this port in the /usr/local/percona/pmm2/config/pmm-agent.yaml file?