VLAN for MCF 5274

[navinshekhar]

Hello,

We are using MCF5274 for transmitting UDP frames. We want to check if MCF5274 can tag VLAN ID on the output Ethernet frames.

Thanks in advance for the support.

regards,

Navin

[TomE]

I don't think VLAN is the hardware's problem. The FEC just sends whatever "data" you want to send after the MAC addresses. If you want a VLAN header then you have to add it (and parse it inbound). Here's what the frames look like:

IEEE 802.1Q - Wikipedia, the free encyclopedia

You'll notice that VLAN-Tagges packets are longer than the "legal maximum" for Ethernet. Is this an issue?

Section "19.1.3 Features" of the MCF5274 Manual states:

Programmable max frame length supports IEEE 802.1 VLAN tags and priority

So that should be fine.

If you search for "VLAN" in this forum you'll find the following post, which says that the uTasker TCP/IP stack supports VLAN:

Re: Which HTTPd is better for M5225X?

Tom

[navinshekhar]

Hi Tom,

thanks for the kind reply.

will it be possible to use MQX RTOS - TCP/IP stack for tagging the VLAN ID in the transmit frame.

as you said that uTasker TCP/IP stack supports VLAN feature, so is there some other stacks too

which supports VLAN feature?

regards,

Navin

[butok · Accepted solution]

Hi Navin,

Sending of VLAN Tag can be done via SW.

MQX/RTCS supports sending of the 8021Q header (based on source code).

From an application, it is possible to set the Priotity Tag (via the RTCS_SO_LINK_TX_8021Q_PRIO socket option), but it is not  possible  to change the VLAN ID. So the VLAN support is not full.

Best regards,

Andrey Butok

[TomE]

> will it be possible to use MQX RTOS

I don't know, I don't use it. I just answer questions in thiw forum by reading the Reference Manuals, searching here and using Google.

You could ask in the MQX forum or read the documentation. I'd suggest starting with the latter.

Tom