mirror of https://github.com/mkerrisk/man-pages
arp.7: grfix
This commit is contained in:
parent
fc59cb811b
commit
caf5129c82
18
man7/arp.7
18
man7/arp.7
|
@ -46,7 +46,7 @@ interfaces described below.
|
||||||
When there is no positive feedback for an existing mapping after some
|
When there is no positive feedback for an existing mapping after some
|
||||||
time (see the
|
time (see the
|
||||||
.I /proc
|
.I /proc
|
||||||
interfaces below) a neighbor cache entry is considered stale.
|
interfaces below), a neighbor cache entry is considered stale.
|
||||||
Positive feedback can be gotten from a higher layer; for example from
|
Positive feedback can be gotten from a higher layer; for example from
|
||||||
a successful TCP ACK.
|
a successful TCP ACK.
|
||||||
Other protocols can signal forward progress
|
Other protocols can signal forward progress
|
||||||
|
@ -54,14 +54,14 @@ using the
|
||||||
.B MSG_CONFIRM
|
.B MSG_CONFIRM
|
||||||
flag to
|
flag to
|
||||||
.BR sendmsg (2).
|
.BR sendmsg (2).
|
||||||
When there is no forward progress ARP tries to reprobe.
|
When there is no forward progress, ARP tries to reprobe.
|
||||||
It first tries to ask a local arp daemon
|
It first tries to ask a local arp daemon
|
||||||
.B app_solicit
|
.B app_solicit
|
||||||
times for an updated MAC address.
|
times for an updated MAC address.
|
||||||
If that fails and an old MAC address is known an unicast probe is send
|
If that fails and an old MAC address is known, a unicast probe is sent
|
||||||
.B ucast_solicit
|
.B ucast_solicit
|
||||||
times.
|
times.
|
||||||
If that fails too it will broadcast a new ARP
|
If that fails too, it will broadcast a new ARP
|
||||||
request to the network.
|
request to the network.
|
||||||
Requests are only send when there is data queued
|
Requests are only send when there is data queued
|
||||||
for sending.
|
for sending.
|
||||||
|
@ -69,7 +69,7 @@ for sending.
|
||||||
Linux will automatically add a non-permanent proxy arp entry when it
|
Linux will automatically add a non-permanent proxy arp entry when it
|
||||||
receives a request for an address it forwards to and proxy arp is
|
receives a request for an address it forwards to and proxy arp is
|
||||||
enabled on the receiving interface.
|
enabled on the receiving interface.
|
||||||
When there is a reject route for the target no proxy arp entry is added.
|
When there is a reject route for the target, no proxy arp entry is added.
|
||||||
.SS Ioctls
|
.SS Ioctls
|
||||||
Three ioctls are available on all
|
Three ioctls are available on all
|
||||||
.B AF_INET
|
.B AF_INET
|
||||||
|
@ -92,7 +92,7 @@ struct arpreq {
|
||||||
|
|
||||||
.BR SIOCSARP ", " SIOCDARP " and " SIOCGARP
|
.BR SIOCSARP ", " SIOCDARP " and " SIOCGARP
|
||||||
respectively set, delete and get an ARP mapping.
|
respectively set, delete and get an ARP mapping.
|
||||||
Setting & deleting ARP maps are privileged operations and may
|
Setting and deleting ARP maps are privileged operations and may
|
||||||
only be performed by a process with the
|
only be performed by a process with the
|
||||||
.B CAP_NET_ADMIN
|
.B CAP_NET_ADMIN
|
||||||
capability or an effective UID of 0.
|
capability or an effective UID of 0.
|
||||||
|
@ -143,7 +143,7 @@ Each interface in the system has its own directory in
|
||||||
.IR /proc/sys/net/ipv4/neigh/ .
|
.IR /proc/sys/net/ipv4/neigh/ .
|
||||||
The setting in the "default" directory is used for all newly created
|
The setting in the "default" directory is used for all newly created
|
||||||
devices.
|
devices.
|
||||||
Unless otherwise specified time-related interfaces are specified
|
Unless otherwise specified, time-related interfaces are specified
|
||||||
in seconds.
|
in seconds.
|
||||||
.TP
|
.TP
|
||||||
.I anycast_delay
|
.I anycast_delay
|
||||||
|
@ -178,7 +178,7 @@ Defaults to 30 seconds.
|
||||||
.TP
|
.TP
|
||||||
.I gc_stale_time
|
.I gc_stale_time
|
||||||
Determines how often to check for stale neighbor entries.
|
Determines how often to check for stale neighbor entries.
|
||||||
When a neighbor entry is considered stale it is resolved again before
|
When a neighbor entry is considered stale, it is resolved again before
|
||||||
sending data to it.
|
sending data to it.
|
||||||
Defaults to 60 seconds.
|
Defaults to 60 seconds.
|
||||||
.TP
|
.TP
|
||||||
|
@ -259,7 +259,7 @@ and kernel version-dependent; see
|
||||||
.BR time (7).
|
.BR time (7).
|
||||||
|
|
||||||
There is no way to signal positive feedback from user space.
|
There is no way to signal positive feedback from user space.
|
||||||
This means connection oriented protocols implemented in user space
|
This means connection-oriented protocols implemented in user space
|
||||||
will generate excessive ARP traffic, because ndisc will regularly
|
will generate excessive ARP traffic, because ndisc will regularly
|
||||||
reprobe the MAC address.
|
reprobe the MAC address.
|
||||||
The same problem applies for some kernel protocols (e.g., NFS over UDP).
|
The same problem applies for some kernel protocols (e.g., NFS over UDP).
|
||||||
|
|
Loading…
Reference in New Issue