ng_one2many man page on FreeBSD

Man page or keyword search:  
man Server   9747 pages
apropos Keyword Search (all sections)
Output format
FreeBSD logo
[printable version]

NG_ONE2MANY(4)		 BSD Kernel Interfaces Manual		NG_ONE2MANY(4)

     ng_one2many — packet multiplexing netgraph node type

     #include <sys/types.h>
     #include <netgraph/ng_one2many.h>

     The one2many provides a simple mechanism for routing packets over several
     links in a one-to-many (and in the reverse direction, many-to-one) fash‐
     ion.  There is a single hook named one, and multiple hooks named many0,
     many1, etc.  Packets received on any of the many hooks are forwarded out
     the one hook.  Packets received on the one hook are forwarded out one or
     more of the many hooks; which hook(s) is determined by the node's config‐
     ured transmit algorithm.  Packets are not altered in any way.

     Each of the connected many links may be considered to be up or down.
     Packets are never delivered out a many hook that is down.	How a link is
     determined to be up or down depends on the node's configured link failure
     detection algorithm.

     Before an interface or link can be plumbed into a group, its status must
     be marked as being “up”.  This is normally setup during the initial boot
     stages by rc.conf(5).  It is also possible to change an interface's sta‐
     tus to “up” by using the ifconfig(8) utility.

	  Packets are delivered out the many hooks in sequential order.	 Each
	  packet goes out on a different many hook.

	  Packets are delivered out all the many hooks.	 Each packet goes out
	  each many hook.

     In the future other algorithms may be added as well.

     The node distinguishes between active and failed links.  Data is sent
     only to active links.  The following link failure detection algorithms
     are available:

	     The node is explicitly told which of the links are up via the
	     NGM_ONE2MANY_SET_CONFIG control message (see below).  Newly con‐
	     nected links are down until configured otherwise.

	     The node listens to flow control message from many hooks, and
	     considers link failed if NGM_LINK_IS_DOWN is received.  If the
	     NGM_LINK_IS_UP message is received, node considers link active.

     In the future other algorithms may be added as well.

     When all links are considered failed, node sends the NGM_LINK_IS_DOWN
     message towards the one hook.  When at least one link comes up, node
     sends the NGM_LINK_IS_UP message towards the one hook.

     This node type supports up to NG_ONE2MANY_MAX_LINKS hooks named many0,
     many1, etc., plus a single hook named one.

     This node type supports the generic control messages, plus the following:

	  Sets the node configuration using a struct ng_one2many_link_config
	  as the control message argument:

	  /* Node configuration structure */
	  struct ng_one2many_config {
	    u_int32_t	xmitAlg;	/* how to distribute packets */
	    u_int32_t	failAlg;	/* how to detect link failure */
	    u_char	enabledLinks[NG_ONE2MANY_MAX_LINKS];

	  Currently, the valid settings for the xmitAlg field are
	  valid settings for failAlg are NG_ONE2MANY_FAIL_MANUAL (default) or

	  Returns the current node configuration in a struct

	  This command takes a 32 bit link number as an argument and returns a
	  struct ng_one2many_link_stats containing statistics for the corre‐
	  sponding many link, which may or may not be currently connected:

	  /* Statistics structure (one for each link) */
	  struct ng_one2many_link_stats {
	    u_int64_t	recvOctets;	/* total octets rec'd on link */
	    u_int64_t	recvPackets;	/* total pkts rec'd on link */
	    u_int64_t	xmitOctets;	/* total octets xmit'd on link */
	    u_int64_t	xmitPackets;	/* total pkts xmit'd on link */

	  To access statistics for the one link, use the link number -1.

	  This command takes a 32 bit link number as an argument and clears
	  the statistics for that link.

	  Same as NGM_ONE2MANY_GET_STATS, but also atomically clears the sta‐
	  tistics for the link as well.

     This node shuts down upon receipt of a NGM_SHUTDOWN control message, or
     when all hooks have been disconnected.

     The following commands will set up Ethernet interfaces fxp0 to deliver
     packets alternating over the physical interfaces corresponding to net‐
     working interfaces fxp0 through fxp3:

       # Plumb nodes together

       ngctl mkpeer fxp0: one2many upper one
       ngctl connect fxp0: fxp0:upper lower many0
       ngctl connect fxp1: fxp0:upper lower many1
       ngctl connect fxp2: fxp0:upper lower many2
       ngctl connect fxp3: fxp0:upper lower many3

       # Allow fxp1 through fxp3 to xmit/recv fxp0 frames

       ngctl msg fxp1: setpromisc 1
       ngctl msg fxp2: setpromisc 1
       ngctl msg fxp3: setpromisc 1
       ngctl msg fxp1: setautosrc 0
       ngctl msg fxp2: setautosrc 0
       ngctl msg fxp3: setautosrc 0

       # Configure all four links as up

       ngctl msg fxp0:upper \
	 setconfig "{ xmitAlg=1 failAlg=1 enabledLinks=[ 1 1 1 1 ] }"

       # Bring up interface

       ifconfig fxp0 netmask 0xfffffffc

     With a similar setup on a peer machine (using the address, a
     point-to-point Ethernet connection with four times normal bandwidth is

     netgraph(4), ng_bridge(4), ng_ether(4), ng_hub(4), ifconfig(8), ngctl(8)

     The ng_one2many node type was implemented in FreeBSD 4.2.

     The one2many netgraph node (with round-robin algorithm) was written by
     Archie Cobbs ⟨⟩.	 The all algorithm was added by Rogier
     R. Mulhuijzen ⟨⟩.

     More transmit and link failure algorithms should be supported.  A good
     candidate is Cisco's Etherchannel.

BSD			       February 19, 2006			   BSD

List of man pages available for FreeBSD

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net