Hello Giovanni
Unlike Access and Trunk ports, the Hybrid port does not have exactly the same meaning across all vendors. Each vendor will use a different terminology for various types of ports that have particular extra features beyond a simple trunk or access port.
For Cisco, the hybrid port is a feature of higher-end Cisco carrier grade switches, such as the ME1200 for example. Hybrid ports are very well described by Cisco in this documentation like so:
Hybrid ports resemble trunk ports in many ways, but adds additional port configuration
features. In addition to the characteristics described for trunk ports, hybrid ports have these abilities:
- Can be configured to be VLAN tag unaware, C-tag aware, S-tag aware, or S-custom-tag
aware.- Ingress filtering can be controlled.
- Ingress acceptance of frames and configuration of egress tagging can be configured
independently
Carrier networks often use QinQ with an outer and inner VLAN tag to separate customer traffic. The C-tag mentioned in the above quote is the Customer tag, or the inner tag, and the S-tag is the Service tag or the outer tag.
So a hybrid port is able to provide additional features that are useful to carriers. An example of a configuration of a hybrid port along with several of the features it delivers can be found at the following Cisco documentation:
Because this is not part of any exam content, and because for Cisco, it is a feature that is limited to a particular specialized kind of switch, there are no lessons concerning this on the site.
I hope this has been helpful!
Laz