VLAN ID 0 with priority tagging
Subsystems (2)
I am trying to send a packet with VLAN ID 0 and non-zero priority.
The VLAN interfaces are created on 2 hosts using
ip link add link eth1 eth1.0 type vlan id 0 egress-qos-map 0:2
When i try to send a packet using ping/arping, on the sender side tcpdump shows that the VLAN tag is added with ID 0 and priority 2.
However, the receiver is receiving the packet with vlan tag stripped.
I am seeing the same behavior with multiple NICs and also with a switch in between the 2 hosts or with the 2 hosts connected over loopback cable.
It looks as if the driver on the send side is stripping the tag if vlan id is 0. Is this correct behavior or a bug?
Any clues on how to get priority tagging to work with vlan id 0?
Thanks
Sridhar
Quoted 8 lines · Sridhar Samudrala
I am trying to send a packet with VLAN ID 0 and non-zero priority.
The VLAN interfaces are created on 2 hosts using
ip link add link eth1 eth1.0 type vlan id 0 egress-qos-map 0:2When i try to send a packet using ping/arping, on the sender side tcpdump shows that the VLAN tag is added with ID 0 and priority 2.
Quoted 9 lines
However, the receiver is receiving the packet with vlan tag stripped.
I am seeing the same behavior with multiple NICs and also with a switch in between the 2 hosts or with the 2 hosts connected over loopback cable.
It looks as if the driver on the send side is stripping the tag if vlan id is 0. Is this correct behavior or a bug?
Any clues on how to get priority tagging to work with vlan id 0?
I sent this note a few weeks back, but i haven't seen any response so far.
Is priority tagging with VLAN ID 0 not supported or is this a bug?
It looks like the NIC hardware is stripping the VLAN tag if the id is 0 even when VLAN tag is added by the software.
Thanks
Sridhar
Quoted 20 lines · Sridhar Samudrala
Quoted 10 lines · Sridhar Samudrala
I am trying to send a packet with VLAN ID 0 and non-zero priority.
The VLAN interfaces are created on 2 hosts using
ip link add link eth1 eth1.0 type vlan id 0 egress-qos-map 0:2When i try to send a packet using ping/arping, on the sender side tcpdump shows that the VLAN tag is added with ID 0 and priority 2.
However, the receiver is receiving the packet with vlan tag stripped.
Quoted 9 lines
I am seeing the same behavior with multiple NICs and also with a switch in
between the 2 hosts or with the 2 hosts connected over loopback cable.It looks as if the driver on the send side is stripping the tag if vlan id is 0.
Is this correct behavior or a bug?
Any clues on how to get priority tagging to work with vlan id 0?
Quoted 6 lines
I sent this note a few weeks back, but i haven't seen any response so far.
Is priority tagging with VLAN ID 0 not supported or is this a bug? It looks like the NIC hardware is stripping the VLAN tag if the id is 0 even when VLAN tag
is added by the software.
eth1.0 should be able to send frames tagged with vid 0. Though I don't know whether there are NICs/drivers that strip tag 0, I can send frames with vid 0 (with e1000e).
Toshiaki Makita
Quoted 23 lines · Toshiaki Makita
Quoted 22 lines · Sridhar Samudrala
Quoted 10 lines · Sridhar Samudrala
I am trying to send a packet with VLAN ID 0 and non-zero priority.
The VLAN interfaces are created on 2 hosts using
ip link add link eth1 eth1.0 type vlan id 0 egress-qos-map 0:2When i try to send a packet using ping/arping, on the sender side tcpdump shows that the VLAN tag is added with ID 0 and priority 2.
However, the receiver is receiving the packet with vlan tag stripped.
Quoted 9 lines
I am seeing the same behavior with multiple NICs and also with a switch in
between the 2 hosts or with the 2 hosts connected over loopback cable.It looks as if the driver on the send side is stripping the tag if vlan id is 0.
Is this correct behavior or a bug?
Any clues on how to get priority tagging to work with vlan id 0?I sent this note a few weeks back, but i haven't seen any response so far.
Quoted 9 lines
Quoted 4 lines
Is priority tagging with VLAN ID 0 not supported or is this a bug? It looks like the NIC hardware is stripping the VLAN tag if the id is 0 even when VLAN tag
is added by the software.eth1.0 should be able to send frames tagged with vid 0. Though I don't know whether there are NICs/drivers that strip tag 0, I can send frames with vid 0 (with e1000e).
Good to know that it works with e1000e. I guess you are seeing the frames with vid 0 at the receiver.
I have tried with ixgbe and be2net and both of them seem to strip tag 0.
Thanks
Sridhar