When deciding whether to use a server publishing rule or access rule, consider the following:
- Access rules allow or deny traffic. Server publishing rules only allow traffic.
- Access rules allow traffic to multiple hosts. Server publishing rules only provide access to a single server.
- An access rule can allow or deny multiple protocols. A server publishing rule can only publish a single protocol.
- An access rule can only use outgoing protocols.
- Port translation can be performed with server publishing, so that the rule publishes services on a different port than the actual service port.
- Server publishing rules allow address translation in both directions, so that Forefront TMG hides both the address of the client from the server, and vice versa.
- Some built-in application filters, such as the SMTP filter, are designed to work with server publishing rules, and not with access rules.
- When you configure access rules or server publishing rules, the network relationship configured between source and destination networks specified in the rules affects how traffic is handled, and should be taken into account.
Thomas W Shinder, M.D., MCSE
Sr. Consultant / Technical Writer