What is MPLS and how does it work?
Multiprotocol Label Switching (MPLS) is a networking technology developed in the 1990s. It is often described as operating at OSI Layer 2.5 because it combines features of both Layer 2 (Data Link) and Layer 3 (Network). You can think of MPLS as a private, dedicated path between two sites.
Unlike traditional Internet routing, which is dynamic and based on routing table decisions at each hop, MPLS uses predefined label-switched paths (LSA). This ensures that packets are forwarded in the same logical order every time. Although the physical path may change, the logical path remains consistent. MPLS forwarding does not rely on each router making independent routing decisions; instead, the path is determined in advance using labels.
How does an SMTP connector work?
A microsoft 365 connector is used to handle incomming email requests by fx. forwarding them to a recipiant. The pros by using an SMTP connector is that you won’t have to validate all your smtp services aginst your domain just the office365, but the major thing is is email security, not all email SMTP services supports sending emails with domain keys (DKIM). DKIM is an essential setting that helps ensuring the delivery of an email.
A Connector can be configured to allow SMTP messages to be forwarded based on the certificate used to send the message or the Public IP the message is forwarded from. SMTP Relay can also be configured with a user account however this is strongly not recommended, becouse it allows for bypassing multi factor authentication in order for it to work smoothly. A conncetor builds on Oauth flows which is an secure authentication and authorization method used in a lot of modern applications.
Best Pratice
- Only allow SMTP clients to use outgoing traffic on port 25 when validating by IP Address.