| Documentation for /proc/sys/net/*	kernel version 2.4.0-test11-pre4 | 
 | 	(c) 1999		Terrehon Bowden <terrehon@pacbell.net> | 
 | 				Bodo Bauer <bb@ricochet.net> | 
 | 	(c) 2000		Jorge Nerin <comandante@zaralinux.com> | 
 | 	(c) 2009		Shen Feng <shen@cn.fujitsu.com> | 
 |  | 
 | For general info and legal blurb, please look in README. | 
 |  | 
 | ============================================================== | 
 |  | 
 | This file contains the documentation for the sysctl files in | 
 | /proc/sys/net and is valid for Linux kernel version 2.4.0-test11-pre4. | 
 |  | 
 | The interface  to  the  networking  parts  of  the  kernel  is  located  in | 
 | /proc/sys/net. The following table shows all possible subdirectories.You may | 
 | see only some of them, depending on your kernel's configuration. | 
 |  | 
 |  | 
 | Table : Subdirectories in /proc/sys/net | 
 | .............................................................................. | 
 |  Directory Content             Directory  Content | 
 |  core      General parameter   appletalk  Appletalk protocol | 
 |  unix      Unix domain sockets netrom     NET/ROM | 
 |  802       E802 protocol       ax25       AX25 | 
 |  ethernet  Ethernet protocol   rose       X.25 PLP layer | 
 |  ipv4      IP version 4        x25        X.25 protocol | 
 |  ipx       IPX                 token-ring IBM token ring | 
 |  bridge    Bridging            decnet     DEC net | 
 |  ipv6      IP version 6 | 
 | .............................................................................. | 
 |  | 
 | 1. /proc/sys/net/core - Network core options | 
 | ------------------------------------------------------- | 
 |  | 
 | rmem_default | 
 | ------------ | 
 |  | 
 | The default setting of the socket receive buffer in bytes. | 
 |  | 
 | rmem_max | 
 | -------- | 
 |  | 
 | The maximum receive socket buffer size in bytes. | 
 |  | 
 | wmem_default | 
 | ------------ | 
 |  | 
 | The default setting (in bytes) of the socket send buffer. | 
 |  | 
 | wmem_max | 
 | -------- | 
 |  | 
 | The maximum send socket buffer size in bytes. | 
 |  | 
 | message_burst and message_cost | 
 | ------------------------------ | 
 |  | 
 | These parameters  are used to limit the warning messages written to the kernel | 
 | log from  the  networking  code.  They  enforce  a  rate  limit  to  make  a | 
 | denial-of-service attack  impossible. A higher message_cost factor, results in | 
 | fewer messages that will be written. Message_burst controls when messages will | 
 | be dropped.  The  default  settings  limit  warning messages to one every five | 
 | seconds. | 
 |  | 
 | warnings | 
 | -------- | 
 |  | 
 | This controls console messages from the networking stack that can occur because | 
 | of problems on the network like duplicate address or bad checksums. Normally, | 
 | this should be enabled, but if the problem persists the messages can be | 
 | disabled. | 
 |  | 
 | netdev_budget | 
 | ------------- | 
 |  | 
 | Maximum number of packets taken from all interfaces in one polling cycle (NAPI | 
 | poll). In one polling cycle interfaces which are registered to polling are | 
 | probed in a round-robin manner. The limit of packets in one such probe can be | 
 | set per-device via sysfs class/net/<device>/weight . | 
 |  | 
 | netdev_max_backlog | 
 | ------------------ | 
 |  | 
 | Maximum number  of  packets,  queued  on  the  INPUT  side, when the interface | 
 | receives packets faster than kernel can process them. | 
 |  | 
 | optmem_max | 
 | ---------- | 
 |  | 
 | Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence | 
 | of struct cmsghdr structures with appended data. | 
 |  | 
 | 2. /proc/sys/net/unix - Parameters for Unix domain sockets | 
 | ------------------------------------------------------- | 
 |  | 
 | There is only one file in this directory. | 
 | unix_dgram_qlen limits the max number of datagrams queued in Unix domain | 
 | socket's buffer. It will not take effect unless PF_UNIX flag is specified. | 
 |  | 
 |  | 
 | 3. /proc/sys/net/ipv4 - IPV4 settings | 
 | ------------------------------------------------------- | 
 | Please see: Documentation/networking/ip-sysctl.txt and ipvs-sysctl.txt for | 
 | descriptions of these entries. | 
 |  | 
 |  | 
 | 4. Appletalk | 
 | ------------------------------------------------------- | 
 |  | 
 | The /proc/sys/net/appletalk  directory  holds the Appletalk configuration data | 
 | when Appletalk is loaded. The configurable parameters are: | 
 |  | 
 | aarp-expiry-time | 
 | ---------------- | 
 |  | 
 | The amount  of  time  we keep an ARP entry before expiring it. Used to age out | 
 | old hosts. | 
 |  | 
 | aarp-resolve-time | 
 | ----------------- | 
 |  | 
 | The amount of time we will spend trying to resolve an Appletalk address. | 
 |  | 
 | aarp-retransmit-limit | 
 | --------------------- | 
 |  | 
 | The number of times we will retransmit a query before giving up. | 
 |  | 
 | aarp-tick-time | 
 | -------------- | 
 |  | 
 | Controls the rate at which expires are checked. | 
 |  | 
 | The directory  /proc/net/appletalk  holds the list of active Appletalk sockets | 
 | on a machine. | 
 |  | 
 | The fields  indicate  the DDP type, the local address (in network:node format) | 
 | the remote  address,  the  size of the transmit pending queue, the size of the | 
 | received queue  (bytes waiting for applications to read) the state and the uid | 
 | owning the socket. | 
 |  | 
 | /proc/net/atalk_iface lists  all  the  interfaces  configured for appletalk.It | 
 | shows the  name  of the interface, its Appletalk address, the network range on | 
 | that address  (or  network number for phase 1 networks), and the status of the | 
 | interface. | 
 |  | 
 | /proc/net/atalk_route lists  each  known  network  route.  It lists the target | 
 | (network) that the route leads to, the router (may be directly connected), the | 
 | route flags, and the device the route is using. | 
 |  | 
 |  | 
 | 5. IPX | 
 | ------------------------------------------------------- | 
 |  | 
 | The IPX protocol has no tunable values in proc/sys/net. | 
 |  | 
 | The IPX  protocol  does,  however,  provide  proc/net/ipx. This lists each IPX | 
 | socket giving  the  local  and  remote  addresses  in  Novell  format (that is | 
 | network:node:port). In  accordance  with  the  strange  Novell  tradition, | 
 | everything but the port is in hex. Not_Connected is displayed for sockets that | 
 | are not  tied to a specific remote address. The Tx and Rx queue sizes indicate | 
 | the number  of  bytes  pending  for  transmission  and  reception.  The  state | 
 | indicates the  state  the  socket  is  in and the uid is the owning uid of the | 
 | socket. | 
 |  | 
 | The /proc/net/ipx_interface  file lists all IPX interfaces. For each interface | 
 | it gives  the network number, the node number, and indicates if the network is | 
 | the primary  network.  It  also  indicates  which  device  it  is bound to (or | 
 | Internal for  internal  networks)  and  the  Frame  Type if appropriate. Linux | 
 | supports 802.3,  802.2,  802.2  SNAP  and DIX (Blue Book) ethernet framing for | 
 | IPX. | 
 |  | 
 | The /proc/net/ipx_route  table  holds  a list of IPX routes. For each route it | 
 | gives the  destination  network, the router node (or Directly) and the network | 
 | address of the router (or Connected) for internal networks. |