|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | DESCRIPTION | SEE ALSO | COLOPHON |
|
|
|
proc_pid_net(5) File Formats Manual proc_pid_net(5)
/proc/pid/net/, /proc/net/ - network layer information
/proc/pid/net/ (since Linux 2.6.25)
See the description of /proc/net.
/proc/net/
This directory contains various files and subdirectories
containing information about the networking layer. The
files contain ASCII structures and are, therefore,
readable with cat(1). However, the standard netstat(8)
suite provides much cleaner access to these files.
With the advent of network namespaces, various information
relating to the network stack is virtualized (see
network_namespaces(7)). Thus, since Linux 2.6.25,
/proc/net is a symbolic link to the directory
/proc/self/net, which contains the same files and
directories as listed below. However, these files and
directories now expose information for the network
namespace of which the process is a member.
/proc/net/arp
This holds an ASCII readable dump of the kernel ARP table
used for address resolutions. It will show both
dynamically learned and preprogrammed ARP entries. The
format is:
IP address HW type Flags HW address Mask Device
192.168.0.50 0x1 0x2 00:50:BF:25:68:F3 * eth0
192.168.0.250 0x1 0xc 00:00:00:00:00:00 * eth0
Here "IP address" is the IPv4 address of the machine and
the "HW type" is the hardware type of the address from
RFC 826. The flags are the internal flags of the ARP
structure (as defined in /usr/include/linux/if_arp.h) and
the "HW address" is the data link layer mapping for that
IP address if it is known.
/proc/net/dev
The dev pseudo-file contains network device status
information. This gives the number of received and sent
packets, the number of errors and collisions and other
basic statistics. These are used by the ifconfig(8)
program to report device status. The format is:
Inter-| Receive | Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed
lo: 2776770 11307 0 0 0 0 0 0 2776770 11307 0 0 0 0 0 0
eth0: 1215645 2751 0 0 0 0 0 0 1782404 4324 0 0 0 427 0 0
ppp0: 1622270 5552 1 0 0 0 0 0 354130 5669 0 0 0 0 0 0
tap0: 7714 81 0 0 0 0 0 0 7714 81 0 0 0 0 0 0
/proc/net/dev_mcast
Defined in /usr/src/linux/net/core/dev_mcast.c:
indx interface_name dmi_u dmi_g dmi_address
2 eth0 1 0 01005e000001
3 eth1 1 0 01005e000001
4 eth2 1 0 01005e000001
/proc/net/igmp
Internet Group Management Protocol. Defined in
/usr/src/linux/net/core/igmp.c.
/proc/net/rarp
This file uses the same format as the arp file and
contains the current reverse mapping database used to
provide rarp(8) reverse address lookup services. If RARP
is not configured into the kernel, this file will not be
present.
/proc/net/raw
Holds a dump of the RAW socket table. Much of the
information is not of use apart from debugging. The "sl"
value is the kernel hash slot for the socket, the
"local_address" is the local address and protocol number
pair. "St" is the internal status of the socket. The
"tx_queue" and "rx_queue" are the outgoing and incoming
data queue in terms of kernel memory usage. The "tr",
"tm->when", and "rexmits" fields are not used by RAW. The
"uid" field holds the effective UID of the creator of the
socket.
/proc/net/snmp
This file holds the ASCII data needed for the IP, ICMP,
TCP, and UDP management information bases for an SNMP
agent.
/proc/net/tcp
Holds a dump of the TCP socket table. Much of the
information is not of use apart from debugging. The "sl"
value is the kernel hash slot for the socket, the
"local_address" is the local address and port number pair.
The "rem_address" is the remote address and port number
pair (if connected). "St" is the internal status of the
socket. The "tx_queue" and "rx_queue" are the outgoing
and incoming data queue in terms of kernel memory usage.
The "tr", "tm->when", and "rexmits" fields hold internal
information of the kernel socket state and are useful only
for debugging. The "uid" field holds the effective UID of
the creator of the socket.
/proc/net/udp
Holds a dump of the UDP socket table. Much of the
information is not of use apart from debugging. The "sl"
value is the kernel hash slot for the socket, the
"local_address" is the local address and port number pair.
The "rem_address" is the remote address and port number
pair (if connected). "St" is the internal status of the
socket. The "tx_queue" and "rx_queue" are the outgoing
and incoming data queue in terms of kernel memory usage.
The "tr", "tm->when", and "rexmits" fields are not used by
UDP. The "uid" field holds the effective UID of the
creator of the socket. The format is:
sl local_address rem_address st tx_queue rx_queue tr rexmits tm->when uid
1: 01642C89:0201 0C642C89:03FF 01 00000000:00000001 01:000071BA 00000000 0
1: 00000000:0801 00000000:0000 0A 00000000:00000000 00:00000000 6F000100 0
1: 00000000:0201 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0
/proc/net/unix
Lists the UNIX domain sockets present within the system
and their status. The format is:
Num RefCount Protocol Flags Type St Inode Path
0: 00000002 00000000 00000000 0001 03 42
1: 00000001 00000000 00010000 0001 01 1948 /dev/printer
The fields are as follows:
Num: the kernel table slot number.
RefCount:
the number of users of the socket.
Protocol:
currently always 0.
Flags: the internal kernel flags holding the status of the
socket.
Type: the socket type. For SOCK_STREAM sockets, this is
0001; for SOCK_DGRAM sockets, it is 0002; and for
SOCK_SEQPACKET sockets, it is 0005.
St: the internal state of the socket.
Inode: the inode number of the socket.
Path: the bound pathname (if any) of the socket. Sockets
in the abstract namespace are included in the list,
and are shown with a Path that commences with the
character '@'.
/proc/net/netfilter/nfnetlink_queue
This file contains information about netfilter user-space
queueing, if used. Each line represents a queue. Queues
that have not been subscribed to by user space are not
shown.
1 4207 0 2 65535 0 0 0 1
(1) (2) (3)(4) (5) (6) (7) (8)
The fields in each line are:
(1) The ID of the queue. This matches what is specified
in the --queue-num or --queue-balance options to the
iptables(8) NFQUEUE target. See
iptables-extensions(8) for more information.
(2) The netlink port ID subscribed to the queue.
(3) The number of packets currently queued and waiting to
be processed by the application.
(4) The copy mode of the queue. It is either 1 (metadata
only) or 2 (also copy payload data to user space).
(5) Copy range; that is, how many bytes of packet payload
should be copied to user space at most.
(6) queue dropped. Number of packets that had to be
dropped by the kernel because too many packets are
already waiting for user space to send back the
mandatory accept/drop verdicts.
(7) queue user dropped. Number of packets that were
dropped within the netlink subsystem. Such drops
usually happen when the corresponding socket buffer
is full; that is, user space is not able to read
messages fast enough.
(8) sequence number. Every queued packet is associated
with a (32-bit) monotonically increasing sequence
number. This shows the ID of the most recent packet
queued.
The last number exists only for compatibility reasons and
is always 1.
proc(5)
This page is part of the man-pages (Linux kernel and C library
user-space interface documentation) project. Information about
the project can be found at
⟨https://www.kernel.org/doc/man-pages/⟩. If you have a bug report
for this manual page, see
⟨https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/tree/CONTRIBUTING⟩.
This page was obtained from the tarball man-pages-6.9.1.tar.gz
fetched from
⟨https://mirrors.edge.kernel.org/pub/linux/docs/man-pages/⟩ on
2024-06-26. If you discover any rendering problems in this HTML
version of the page, or you believe there is a better or more up-
to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to
[email protected]
Linux man-pages 6.9.1 2024-05-02 proc_pid_net(5)
Pages that refer to this page: proc_sys_net(5)
|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|