# (Updated) Linux TC HW Offload not working on ConnectX-5/6
**URL:** https://forums.developer.nvidia.com/t/updated-linux-tc-hw-offload-not-working-on-connectx-5-6/283885
**Category:** Ethernet Adapter Cards
**Tags:** tc, offload-features, linux
**Created:** [February 23, 2024, 8:07pm UTC](https://forums.developer.nvidia.com/t/updated-linux-tc-hw-offload-not-working-on-connectx-5-6/283885 "2024-02-23T20:07:50Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@shane.miller](https://forums.developer.nvidia.com/u/shane.miller)
#### Post date: [February 23, 2024, 8:07pm UTC](https://forums.developer.nvidia.com/t/updated-linux-tc-hw-offload-not-working-on-connectx-5-6/283885/1 "2024-02-23T20:07:50Z")
Goal : Mirror Incoming/Outgoing Packets Between Two Ethernet Ports in Hardware
Env : Fresh, unmodified install of Unbuntu 22.04 on bare metal Intel x86\_64
Dual port ConnectX-5 in PCI slots 0000:01.00/0000:01.01
Two ethernet links ‘enp1s0f0’, ‘enp1s0f1’
Basic Solution: Run these Linux Commands:
0 # enable HW offload
1 ethtool -K enp1s0f0 hw-tc-offload on
2 ethtool -K enp1s0f1 hw-tc-offload on
3 # ingress mirror in HW
4 tc qdisc add dev enp1s0f1 ingress
5 tc filter add dev enp1s0f1 ingress flower verbose skip\_sw action mirred egress mirror dev enp1s0f0
7 # egress mirror in HW
8 tc qdisc add dev enp1s0f1 root prio
9 tc filter add dev enp1s0f1 root flower verbose skip\_sw action mirred egress mirror dev enp1s0f0
The filter commands give error:
**Error: mlx5\_core: Not implemented offload action.** There is no additional detail in `dmesg` on Ubuntu.
These filter variations DO WORK:
- In line 5, 9 replace keyword “mirror” with “redirect” i.e. HW redirect works
- In line 5, 9 remove keyword “skip\_sw” i.e. mirror works in kernel/software
This is a very basic problem:
- A successful install of MLNX\_OFED\_LINUX-23.10-1.1.9.0-ubuntu22.04-x86\_64.tgz
with or without updating the ConnectX-5 firmware give the same error
- The same errors occurs on stock RHEL8. In the RHEL dmesg cryptically mentions
class(ifier) error.
- I’ve seen this issue on Connect6-X NICs too
- I’ve seen the same errors on Ubuntu 24.xx
This question is a repeat of,
> [@ASAP2 port mirroring with tc](https://forums.developer.nvidia.com/t/asap2-port-mirroring-with-tc/206577):
>
> Does ASAP2 support port mirroring on a MCX512A-ACAT? i.e can we replicate what’s going out of one port on a second. We are trying this with 4.7 driver on Linux and latest firmware as follows: tc qdisc add dev ens1f0 handle 1: root prio tc filter add dev ens1f0 parent 1: flower skip\_sw dst\_mac e4:11:22:11:4a:51 action mirred egress mirror dev ens1f1 But we get a cryptic error message from tc, is this supported and if so what filters are allowed?
which was **never answered** right. Variations can be found across the WWW too.
This error comes from omitting act-\>id=5 (MIRRER) in the MLX5\_CORE module but supporting REDIRECT (v5.15.136 is the kernel version for Ubuntu 22.04LTS):
> **[flow\_offload.h - include/net/flow\_offload.h - Linux source code v5.15.136 -...](https://elixir.bootlin.com/linux/v5.15.136/source/include/net/flow_offload.h#L126)**
>
> Elixir Cross Referencer - source code of Linux v5.15.136: include/net/flow\_offload.h
> **[en\_tc.c - drivers/net/ethernet/mellanox/mlx5/core/en\_tc.c - Linux source...](https://elixir.bootlin.com/linux/v5.15.136/source/drivers/net/ethernet/mellanox/mlx5/core/en_tc.c#L3614)**
>
> Elixir Cross Referencer - source code of Linux v5.15.136: drivers/net/ethernet/mellanox/mlx5/core/en\_tc.c
This means the MLX5\_CORE driver does not support the TC fragment “action mirred (ingress|egress) mirror”.
How can packets be mirrored then between ethernet links?
---
### Author:  [@sribhargavid](https://forums.developer.nvidia.com/u/sribhargavid)
#### Post date: [February 28, 2024, 8:10pm UTC](https://forums.developer.nvidia.com/t/updated-linux-tc-hw-offload-not-working-on-connectx-5-6/283885/2 "2024-02-28T20:10:54Z")
Hello @shane.miller,
Thank you for posting your query on our community. in order to debug this issue further, we would request you to submit a support ticket along with a sysinfo snapshot captured from the node for further troubleshooting. The support ticket can be opened by emailing " [Networking-support@nvidia.com](mailto:Networking-support@nvidia.com) ".
Thanks,
Bhargavi
---
### Author:  [@shane.miller](https://forums.developer.nvidia.com/u/shane.miller)
#### Post date: [March 8, 2024, 10:59pm UTC](https://forums.developer.nvidia.com/t/updated-linux-tc-hw-offload-not-working-on-connectx-5-6/283885/3 "2024-03-08T22:59:26Z")
NVIDIA support has been no help.
However, I believe I was able to figure out how to do this. When testing is done I will post a link here to the solution, which is how NVIDIA should provide technical documentation.
---
### Author:  [@IamAries](https://forums.developer.nvidia.com/u/IamAries)
#### Post date: [November 22, 2024, 3:38pm UTC](https://forums.developer.nvidia.com/t/updated-linux-tc-hw-offload-not-working-on-connectx-5-6/283885/4 "2024-11-22T15:38:10Z")
How did you end up solving this issue?