CentOS 7 SNMP端口始终关闭

即使我可以在这里看到端口打开：

[matias@Centos_7_VM ~]$ sudo firewall-cmd --list-all
[sudo] password for matias:
public (active)
  target: default
  icmp-block-inversion: no
  interfaces: ens33
  sources:
  services: ssh dhcpv6-client
  ports: 80/tcp 10050/tcp 50000/tcp 161/tcp 160/tcp
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  rich rules:

当我试图从外面击中这个端口时,我总是得到关闭它.即使是nmap也同意这一点：

Starting Nmap 7.01 ( https://nmap.org ) at 2018-08-01 14:52 -03
Nmap scan report for Centos_7_VM (192.168.43.216)
Host is up (0.52s latency).
Not shown: 996 filtered ports
PORT      STATE  SERVICE
22/tcp    open   ssh
80/tcp    open   http
161/tcp   closed snmp
50000/tcp closed ibm-db2

我还能做些什么来打开这些端口？ (是的,当我最初打开端口时,我重新加载了firewalld.)