Limitations

libpcap Installation

Platform
Napatech SmartNIC
Content Type
Software Installation Guide
Capture Software Version
Link™ Capture Software 12.1

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 version 1.7.3 and later supports all libpcap functions with a few limitations:

libpcap Function Limitation
int pcap_get_selectable_fd(pcap_t *) Linux only.
int pcap_fileno(pcap_t *) Linux only.
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.
int pcap_getnonblock_fd(pcap_t *, char *) Unsupported. Result undefined.
int pcap_setnonblock_fd(pcap_t *p, int, char *) Unsupported. Result undefined.

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

2GD

Second-Generation Driver (Napatech Driver Software)

3GA

Third-Generation Architecture

3GD

Third-Generation Driver (Napatech Software Suite)

4GA

Fourth-Generation Architecture

BNF

Backus-Naur Form

BP

ByPass

BSD

Berkeley Software Distribution

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

DN-0236

Napatech, NT Adapters with Napatech Driver Software, LibPCAP Installation Guide

DN-0384

Napatech, NT 3GA Accelerators with Napatech Software Suite, Time-Stamping and Time Synchronization, User Guide

DN-0393

Napatech, NT Accelerators with Napatech Software Suite, Software Installation for FreeBSD, Software Installation Guide