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From my Cisco CCNA documentation:

Routed ports are used for point-to-point links. Connecting WAN routers and security devices are examples of the use of routed ports. In a switched network, routed ports are mostly configured between switches in the core and distribution layer. The figure illustrates an example of routed ports in a campus switched network.

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I don't understand what are the benefit of having a routed port between the distribution and access, and more generally, the purpose of routed ports except for inter-VLAN routing like with the router-on-a-stick method (and even there, it seems that SVI are a better approach).

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    That depends on your design goals, think about the differences between how the two interfaces act and you will understand what the implications of each are. A trunk port is a L2 interface and it will forward all broadcasts and unknow unicasts out of the interface, where a routed interface will not. There are other thoughts when it comes to filtering and security when using L3 interfaces.
    – Cow
    Commented Jun 25, 2019 at 9:11
  • I found the best article on Routed Ports, VLAN Routing with Layer 3 Switch Routed Ports ciscopress.com/articles/article.asp?p=2990405&seqNum=4
    – Sharique
    Commented Apr 14, 2021 at 15:12

2 Answers 2

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Routed Interface means it is a Layer3 physical Ports which is not supported to Layer 2 communications such as STP.

All Ethernet ports are routed interfaces by default.(in router) You can change this default behavior with the CLI setup script or through the system default switchport command.

Routed ports are supported to all routing protocols.

But don't misunderstand, SVI and routed interface. SVI is a virtual or logical interface which assigned to one VLAN. But Routed port is a Physical interface.

IP address assigning, enable routing and layer 3 functions can be done on Routed Interface.

Reference cisco

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  • I got the point that a routed port is a L3 interface, without STP and so one. What I don't get is in which context someone will use it. Why not simply put a router if L3 function are needed?
    – Nakrule
    Commented Jun 25, 2019 at 9:17
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    Simple answer is you can do routing without Router. It is more cost effective, easy manage and many reasons behind that.... Especially when you work with VLANs. Your image also depict same scenario
    – infra
    Commented Jun 25, 2019 at 9:19
  • @JFL in your comment "...on routers, on a (layer 3) switch, they are switched by default...", I think you meant layer 2 switch. Layer 2 switches are trunk ports by default (usually). Most modern (enterprise/carrier grade) switches are capable of both switching at layer 2 as well as routing at layer 3 (and combinations thereof...some even all the way through layer 7)
    – sietecFAST
    Commented Jun 28, 2019 at 23:21
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  • On some devices, a routed L3 interface may require less hardware resources (from TCAM) than a VLAN plus SVI.
  • A routed port can enable you to re-use the same VLAN ID from another L3 port or from an L2 VLAN without any risk of L2 traffic in between.
  • A routed port may be easier to manage by an admin, especially with ECMP or similar (no need to twiddle with MSTP instances or such).
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