Protocol Filter

Frames can be filtered based on various protocol information.

Supported protocols

Napatech SmartNICs with Link-Capture™ Software decode every received frame and classify according to the various protocol layers as follows.

Encapsulation: ISL, CFP, VLAN, or MPLS
Broadcast, Multicast, Unicast
Layer 2: Ether II, LLC, SNAP, Raw, PPPoEDiscovery, PPPoESession
Layer 3: IP, IPv4, IPv6,
Layer 4: UDP, TCP, ICMP, SCTP
Tunneling: GREv0, GREv1, GTPv0-U, GTPv1-U, GTPv1-C, GTPv2-C, GTPv1v2-C, GTPv1-U-GPDU, GTPv1-U-Signal, IPinIP, EtherIP, VXLAN, NVGRE, EoMPLS
Inner encapsulation: VLAN, MPLS
Inner layer 2: EtherII
Inner layer 3: IP, IPv4, IPv6,
Inner layer 4: UDP, TCP, ICMP, SCTP

For tunneled traffic, both outer and inner layer protocols are decoded.

NTPL examples

This example configures the SmartNIC to capture IPv4 frames containing the UDP protocol.

Assign[streamid=0] = (Layer3Protocol==IPv4) AND (Layer4Protocol==UDP)

The following example shows how to filter tunneled IPv4 traffic which contains the IPv4 or IPv6 protocol in the inner layer.

// Define a macro for IPv4 frames containing inner IPv4.
Define isIPv4_containing_IPv4 = Macro("Layer3Protocol==IPv4 AND InnerLayer3Protocol==IPv4")

// Define a macro for IPv4 frames containing inner IPv6.
Define isIPv4_containing_IPv6 = Macro("Layer3Protocol==IPv4 AND InnerLayer3Protocol==IPv6")

Assign[streamid=1] = isIPv4_containing_IPv4
Assign[streamid=2] = isIPv4_containing_IPv6

This following example sets filters for:

Delivering GTP-C traffic to stream 0.
Filtering UDP traffic inside the GTPv1 tunnel and distributing based on the inner 5-tuple hash mode.

// Define a filter for GTP-U traffic.
Define isGTP-U = Filter(TunnelType==GTPv1-U AND InnerLayer3Protocol==IPv4 AND \\
InnerLayer4Protocol==UDP)

// Define a filter for GTP-C traffic.
Define isGTP-C = Filter(TunnelType==GTPv2-C)

// Distribute traffic based on inner UDP sessions.
HashMode=HashInner5TupleSorted

// Stream 0: GTPv2-C traffic.
Assign[StreamId=0] = isGTP-C

// Stream 1 to 16: GTPv2 traffic hashed using HashInner5TupleSorted.
Assign[StreamId=(1..16)] = isGTP-U

MPLS and VLAN encapsulated frames can be filtered as follows.

Assign[streamid=3] = (Encapsulation==MPLS)
Assign[streamid=4] = (Encapsulation==VLAN)

Note: The TPID values, 0x8100 (33024) and 0x88a8 (34984), are always valid for VLAN tags in the SmartNIC. An additional TPID value for VLAN tags is configurable in the /opt/napatech3/config/ntservice.ini file. For example:

AltTPID = 0x9100

The following NTPL example configures the SmartNIC to filter VXLAN encapsulated frames.

Assign[StreamId=5] = TunnelType==VxLan

Note: Alternative UDP port numbers for VXLAN are configurable in the /opt/napatech3/config/ntservice.ini file.

VXLANAltDestinationPorts = 8472, 8473

A maximum of two alternative UDP port numbers are supported. The standard UDP port, 4789, is always matched regardless of this configuration.