Hiding TCP or UDP ports will cause problems on masked connections where so-called "authenticate" or "ident" queries, as used by some mail and news servers to request additional information from users, are no longer rejected correctly. These servers then time out, resulting in considerable delays in the delivery of mail or news. In order to overcome this problem when stealth mode is switched on, stealth mode is deactivated temporarily for the port in question. The firewall recognizes that the internal station's wish to establish contact with a mail (SMTP, POP3, IMAP2) or news server (NNTP) and opens the port for 20 seconds. You can use this option to suppress the temporary deactivation of stealth mode for the authentication port.
- SNMP ID:
- 2.8.10.16
- Console path:
- Setup > IP-Router > Firewall
- Possible values:
- stealth
- No
- Default:
- stealth
