Limitations

libpcap Installation

Platform
Intel® PAC
Napatech SmartNIC
Content Type
Software Installation Guide

Filtering

Filtering using pcap_setfilter is SW-based and does not utilize the filtering capabilities of the SmartNICs. Filtering using Napatech libpcap with configuration files is HW-based. It is also possible to use the ntpl tool (see DN-0449) for HW filtering after the driver has been loaded.

libpcap functions

Napatech libpcap supports all libpcap functions with a few limitations:

libpcap Function Limitation
int pcap_setdirection(pcap_t *, pcap_direction_t) Supports only PCAP_D_N, received packets.
int pcap_set_promisc(pcap_t *, int) Accepted, but will always run promiscuous mode.
int pcap_set_timeout(pcap_t *, int) Has no effect. Will always run 100 ms time-out.
int pcap_set_tstamp_type(pcap_t *, int) Supports only PCAP_TSTAMP_ADAPTER_UNSYNCED SmartNIC time-stamping.
int pcap_set_buffer_size(pcap_t *, int) Has no effect. Will always run zero-copy mode.

Style Conventions

Bold typeface is used for names of, for instance, user interface elements and software components.

Italic typeface is used for replaceable text.

Monospaced typeface is used for code, commands and file names.

Abbreviations

BNF

Backus-Naur Form

BP

ByPass

CentOS

Community ENTerprise Operating System

CRC

Cyclic Redundancy Check

DN

Document Number

GCC

GNU Compiler Collection

Gen

GENeration

GNU

GNU’s Not Unix

HB

Host Buffer

hba

Host Buffer Allowance

http

HyperText Transfer Protocol

https

HyperText Transfer Protocol Secure

HW

HardWare

Id, ID

IDentifier

IFG

Inter-Frame Gap

libpcap

Packet CAPture LIBrary

LSB

Least Significant Bit

Min

MINimum

MSB

Most Significant Bit

NDIS

Network Driver Interface Specification

nt, NT

NapaTech

NTAPI

NapaTech Application Programming Interface

ntpl, Ntpl, NTPL

NapaTech Programming Language

Numa, NUMA

Non-Uniform Memory Access

pcap, PCAP

Packet CAPture

PCI

Peripheral Component Interconnect

PTP

Precision Time Protocol

Rev.

REVision

RHEL

Red Hat Enterprise Linux

Rx, RX

Receive

STD

STanDard

SW

SoftWare

tx, Tx, TX

Transmission/Transmit

References