Netro Support: Firewall

Netro provides services to it's customers including:
- Mail including:
  - SMTP (port 25)
  - SMTPS (port 465)
  - Submission (port 587)
  - POP3 (port 110)
  - POP3S (port 995)
- FTP including:
  - FTP (port 21)
  - FTPS (port 990) on newer servers.

To protect our network, we run an IDS (Intrustion Detection System) to mitigate brute force attacks.
If three login attempts are made with the wrong password, our system will automatically block the originating IP address for three hours,
similar to how banks block three failed PIN attempts on ATM's and EFTPOS terminals for 24 hours.
Please note: The block time is subject to change.

Connectivity can be tested using tools such as:

1. Using telnet
Install Telnet Client e.g.
telnet pop3
telnet 587
telnet ftp
telnet 4

- Escape Character is 'CTRL+]'
- quit to exit (Type help for more information).

2. Using OpenSSL
openssl s_client -connect
openssl s_client -connect -starttls smtp
openssl s_client -connect -starttls pop3
openssl s_client -connect
openssl s_client -connect -starttls ftp
openssl s_client -connect

3. Using nmap
Downloading Nmap
nmap --script smtp-commands -p smtps
nmap --script pop3-capabilities -p pop3s
nmap --script banner -p 4

If you can't connect, try:
- From different device/network
- Different server, such as Gmail:
  Read Gmail messages on other email clients using POP
  pop &
- Contact support, include your IP address.

- Wikipedia: IDS
- Post Office Protocol (POP)
- Simple Mail Transfer Protocol (SMTP)
- Extended Simple Mail Transfer Protocol (ESMTP)
- Simple Authentication and Security Layer (SASL)
- Wikipedia: FTP
- HyperText Transfer Protocol (HTTP)
- Transport Layer Security (TLS) (including predecessor Secure Sockets Layer (SSL)
- Opportunistic TLS e.g. STARTTLS & STRIPTLS vulnerability.
- Email encryption in transit
- IANA: Service Name and Transport Protocol Port Number Registry

Updated Dec-18