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