Xilinx Alveo X3522 User Manual page 35

Allowing Specific UDP IPv4 Multicast Traffic
When the multicast-mismatch drop filter is present, UDP IPv4 multicast traffic will only be
delivered to an application if a steering filter for the associate destination IP and port is added.
For kernel applications, this can be achieved using further ethtool ntuple rules. An example is
given in the following section of a PTP client that needs to receive multicast traffic.
• Applications running under Onload or using the TCPDirect API will automatically have filters
inserted with no changes to the applications or system configuration.
• ef_vi applications should insert filters for the traffic they wish to receive as has traditionally
been the case for applications written to work with X2 adapters.
Allowing PTP Traffic
The following ethtool ntuple rules will allow a PTP client to receive required traffic via the kernel
driver (on queue 0) for PTP operating in end-to-end mode:
$ sudo ethtool -N enp2s0f0np0 flow-type udp4 dst-ip 224.0.1.129 dst-port
319 action 0
Added rule with ID 0
$ sudo ethtool -N enp2s0f0np0 flow-type udp4 dst-ip 224.0.1.129 dst-port
320 action 0
Added rule with ID 1
These rules should be applied to all interfaces that need to receive PTP traffic. If using a bond
then the rules should be applied to all underlying interfaces.
If operating PTP in peer-to-peer mode then the following rules are required in addition to those
above.
$ sudo ethtool -N enp2s0f0np0 flow-type udp4 dst-ip 224.0.0.107 dst-port
319 action 0
Added rule with ID 2
$ sudo ethtool -N enp2s0f0np0 flow-type udp4 dst-ip 224.0.0.107 dst-port
320 action 0
Added rule with ID 3
IGMP, Layer 2 Multicast and IPv6
Because the multicast mismatch filter described here is for UDP IPv4 multicast traffic only, IGMP
traffic will still be allowed to pass to the kernel without any specific exceptions. This will also be
the case for any other layer 2 multicast protocols and IPv6 traffic.
UG1523 (v1.0) October 18, 2022
Alveo X3522 User Guide
Chapter 5: Tuning
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