hybrid port usage in real scenarios

Hybrid port

As shown in Figure 1, a hybrid port on a switch can connect either to a host or to another switch. A hybrid port can connect either to an access link or to a trunk link. The hybrid port allows multiple VLAN frames and removes tags from some VLAN frames on the outbound port.

for example,  when a port connect to an IP phone, then a PC connect to the IP phone.  If the IP phone and the PC can not process the packet with VLAN tag, and neet to seperate the different data to different vlan,  then hybrid is necessary.

Hi l00192083 ,

I cant see the picture . 

Hi p00187531

"If the IP phone and the PC can not process the packet with VLAN tag, and neet to seperate the different data to different vlan"

I am not following your above statement . Can you kindly explain the above .It would be a great help 

Thanks 

HI  l00192083

Adds a tag with the default VLAN ID to an untagged frame and accepts the frame if the port permits the default VLAN ID

The above statement is confusing me time to time . The confusion is when a frame is tagged . When a frame leaves the port or trunk.?

What i understood a phone is connected to a port and pc is connected to the phone then i lost :)

I cannot visualize the scenarios provided .simply stuck with access port and trunk port 

Please provide some diagram , it would be a great help .

I can't think of a real life scenario where hybrid port is used.

but hybrid port is similar to trunk.  only difference is trunk can only strip vlan tag on one vlan with PVID setting.

hybrid port can strip multiple vlans with 'hybrid untagged vlan' setting.

I still wonder if this kind of thing is legal :)

It surely is an issue for the switch, since I cannot separate traffic on the switch itself, eg. IPv4 on VLANIF14 and ARP on VLANIF 806. (It's a LI Switch, thus not permitting more than one VLANIF).

One question: I think that the S5720 keeps a MAC-Database for each VLAN. Is that correct?

Me again!

I'm studying for my HCNA and I have found another use cases for it. And I can tell you that hybrid ports will be THE way to go in the future!

-------- Separate IPv4 and IPv6 traffic --------

You can use hybrid ports to separate IPv4 and IPv6 traffic into separate VLANs. How? Here it is:

You have to use a protocol based VLAN -> 4.7.1.5 Protocol-based VLAN Assignment. L2 frames carry an ETHERTYPE-tag. This in combination with a protocol-based VLAN assignment allows you to separate IPv4 and IPv6 traffic into VLANs.

E.g. you create a VLAN 14 for IPv4 and VLAN 16 for IPv6 traffic. In fact this is quite cool and absolutely the way to go in my opinion.

-------- Jumbo Frames --------

There is a proposal to tag JUMBO-Frames with a special Ethertype: 0x8870. You could detect jumbos automatically and let them run trough a special VLAN dedicated to this type of traffic, also with a protocol based VLAN assignment.

--------  Other use cases --------

There are other interesting Ethertypes: 0x88E5 MAC security (IEEE 802.1AE) ; 0x0806 Address Resolution Protocol (ARP) ; 0x8902 IEEE 802.1ag Connectivity Fault Management (CFM) Protocol / ITU-T Recommendation Y.1731 (OAM) so maybe there are other possibilities...

What do you think?