Ports which should be opened

For server some ports should be opened or forwarded to M4/MOR server:

• TCP 80 - for GUI/HTTP
• TCP 22 - for SSH connection
• TCP 25/465 - for SMTP / SMTP over SSL (TLS)
• TCP 443 - for GUI/HTTPS
• UDP 694 - for Heartbeat.
• TCP 3306 - for MySQL replication
• TCP 3690 - for SVN connections
• UDP 4569 - for IAX2 connection (Only for MOR)
• UDP 5060 to 5070, 10000-20000(10000-50000 in M4) - for SIP connection
• TCP/UDP 123 - Network Time Protocol
• TCP/UDP 1720 - for H.323 Protocol (Only for MOR)
• TCP/UDP 5038 - for Asterisk manager interface (Only for MOR)
• TCP 9200,9300 - Elasticsearch service
• TCP/UDP 10050 - for Zabbix monitoring
• UDP 4000 - 4999 for T.38 support (Only for MOR)

You can test which TCP ports are opened using nmap tool:

nmap -vv -p0 your server's IP address

https://www.virtualizationhero.com/docs/manuals/linux/RHL-9-Manual/security-guide/s1-server-ports.html

iptables config

For Asterisk (only) server:

iptables -A INPUT -p tcp --dport ssh -j ACCEPT
iptables -A INPUT -p tcp --dport 5038 -j ACCEPT
iptables -A INPUT -p udp --dport 5038 -j ACCEPT
iptables -A INPUT -p udp --dport 4569 -j ACCEPT
iptables -A INPUT -p udp --dport 1720 -j ACCEPT
iptables -A INPUT -p udp --dport 5060:5070 -j ACCEPT
iptables -A INPUT -p udp --dport 10000:20000 -j ACCEPT
iptables -A INPUT -p udp --dport 4000:4999 -j ACCEPT
iptables -A INPUT -j DROP