'\" t
.\" This man page is Copyright (C) 1999 Matthew Wilcox <willy@bofh.ai>.
.\" Permission is granted to distribute possibly modified copies
.\" of this page provided the header is included verbatim,
.\" and in case of nontrivial modification author and date
.\" of the modification is added to the header.
.\" Modified June 1999 Andi Kleen
.\" $Id: arp.7,v 1.9 2001/03/12 08:45:27 nakano Exp $
.\"
.\" Japanese Version Copyright (c) 1999-2001 NAKANO Takeo all rights reserved.
.\" Translated Mon 6 Dec 1999 by NAKANO Takeo <nakano@apm.seikei.ac.jp>
.\" Updated&Modified Fri 16 Feb 2001 by NAKANO Takeo
.\"
.\"WORD		permanent		¸
.\"WORD		neighbor cache entry	˵å奨ȥ
.\"WORD		stale			Ťʤä
.\"WORD		proxy arp		 arp
.\"WORD		garbage collect (-or)	١쥯(쥯)
.\"WORD		capability		
.\"WORD		neighbor soliciation message	˵å
.\"WORD		network flooding	ͥåȥեåǥ
.\"WORD		thrashing		å
.\"WORD		connection oriented	³ظ
.\"WORD		forward progress	եɥץ쥹
.\"
.TH ARP 7 2007-07-27 "Linux" "Linux Programmer's Manual"
.SH ̾
arp \- Linux ARP ͥ⥸塼
.SH 
Υͥץȥ⥸塼ϡ
RFC\ 826 Ƥ Address Resolution Protocol 
ΤǤ롣 ARP ϡ쥯Ȥ³줿ͥåȥǡ
 2 ؤΥϡɥɥ쥹IPv4 ץȥ륢ɥ쥹
Ѵ뤿Ѥ롣桼ξ
̾ľܤΥ⥸塼˴ؤ뤳ȤϤʤ
ϥͥ¾Υץȥ˥ӥ󶡤ΤǤ롣
.PP
桼ץϡ
.BR packet (7)
åȤѤ ARP ѥåȤ뤳ȤǤ롣
ARP å桼֤Ǵ뤳ȤǤ롣
ˤ
.BR netlink (7)
Ѥ롣 ARP ơ֥ǽǡˤǤդ
.B PF_INET
åȤ
.BR ioctl (2)
Ѥ롣
.PP
ARP ⥸塼ϥϡɥɥ쥹ץȥ륢ɥ쥹ؤ
ޥåԥ󥰤Υå롣å礭ˤ¤
ΤǡŤȥѤʤȥϥ١쥯
롣 permanent (¸) ޡĤ줿ȥϡ
褷ƥ١쥯ˤäƾõʤ
ioctl ѤХåľ뤳ȤǤ롣
ޤʲƤ褦 sysctl Ѥ
åο񤤤ѹǤ롣
.PP
¸ߤƤޥåԥ󥰤Фơ
ΥեɥХå֤ʤ (ʲ sysctl 򸫤) ȡ
˵å奨ȥ (neighbor cache entry) 
Ťʤä (stale) Ȥߤʤ롣
ΥեɥХåϹ̤Υ쥤䡼Ǥ
(㤨 TCP ACK ʤ)
¾Υץȥϡ
.BR sendmsg (2)

.B MSG_CONFIRM
ե饰Ѥ뤳Ȥˤäơ
եɥץ쥹 (forward progress) 򥷥ʥǤ롣
եɥץ쥹ʤС
ARP ϺƤӥץ֤ߤ롣
ޤ arp ǡ碌Ԥ
줿 MAC ɥ쥹褦Ȥ롣
ΥꥯȤ
.B app_solicit
ԤȡŤ MAC ɥ쥹狼äƤϡ
unicast Υץ֤
.B ucaset_solicit
롣ˤ⼺Ԥȡ ARP ꥯ
ͥåȥ˥֥ɥ㥹Ȥ롣
ꥯȤϡǡ塼ˤʤʤ
.PP
Linux ϡ륢ɥ쥹ؤΥꥯȤեɤ
󥿡ե arp ͭˤʤäƤˤϡ
ưŪˤΥɥ쥹 non-permanent  arp ȥɲä롣
ΥåȤ reject route äˤϡ
 arp ȥϰɲäʤ
.SS ioctl
٤Ƥ
.B PF_INET
åȤǤϡ 3 Ĥ ioctl ѤǤ롣

.I struct arpreq
ؤΥݥ󥿤˼롣

.in +4n
.nf
struct arpreq {
    struct sockaddr arp_pa;      /* protocol address */
    struct sockaddr arp_ha;      /* hardware address */
    int             arp_flags;   /* flags */
    struct sockaddr arp_netmask; /* netmask of protocol address */
    char            arp_dev[16];
};
.fi
.in

.BR SIOCSARP ", " SIOCDARP ", " SIOCGARP
ϡ줾 ARP ޥåԥ󥰤ꡦ롣
ARP ޥåפȺøɬפǤꡢ
.B CAP_NET_ADMIN
¤ĥץ¹ԥ桼 ID  0 Υץ
Ǥʤм¹ԤǤʤ
.PP
.I arp_pa

.B AF_INET
åȤǤʤФʤ餺
.I arp_ha

.I arp_dev
ꤵ줿ǥХƱפǤʤФʤʤ
.I arp_dev
ϥǥХ̾򼨤ǽü줿ʸǤ롣
.RS
.TS
tab(:) allbox;
c s
l l.
\fIarp_flags\fR
ե饰:̣
ATF_COM:ȴλ
ATF_PERM:ȥ peramanent ˤ
ATF_PUBL:ȥ publish 
ATF_USETRAILERS:trailer ɬ
ATF_NETMASK:netmask Ѥ
ATF_DONTPUB:ʤ
.TE
.RE

.PP
.B ATF_NETMASK
ե饰åȤƤȤˤϡ
.I arp_netmask
ͭǤʤФʤʤ
Linux 2.2 ͥåȥ ARP ȥ򥵥ݡȤƤʤΤǡ
 0xffffffff ˥åȤƤ뤤
¸ arp ȥˤ 0 ˤƤɬפ롣
.B ATF_USETRAILERS
 obsolete ʤΤǡѤ٤Ǥʤ
.SS sysctl
ARP ǤϡХʥѥ᡼䥤󥿡եȤΥѥ᡼
sysctl ̤ꤹ뤳ȤǤ롣
 sysctl إˤϡ
.I proc/sys/net/ipv4/neigh/*/*
եɤ߽񤭤ˡȡ󥿡եФ
.BR sysctl (2)
Ѥˡ롣
ƥˤ뤽줾Υ󥿡եˤϡ
줾бǥ쥯ȥ꤬
/proc/sys/net/ipv4/neigh/ ʲˤ롣
`default' ǥ쥯ȥФ򤹤ȡ
ʹǥХƤФƤ꤬Ѥ롣
ä˻꤬ʤС
֤˴ؤ sysctl ñ̤äǤ롣
.TP
.B anycast_delay
IPv6 ζ˵å (neighbor soliciation message)
˱ޤǤκٱ (jiffy ñ)
anycast ΥݡȤϤޤƤʤ
ǥեȤ 1 á
.TP
.B app_solicit
桼֤ ARP ǡ netlink Ѥõ
ۤȥޥ㥹Ȥˤõ˰ܹԤ
.RI ( mcast_solicit
򸫤)
.TP
.B base_reachable_time
˵ΥۥȤߤĤȡΥȥ
.IR base_reachable_time "/2  3*" base_reachable_time /2
δ֤Υͤλ֡ͭǤȤߤʤ롣
ȥͭϡ̤Υץȥ뤫ݥƥ֤ʥեɥХå
ȱĹ롣ǥեȤ 30 á
.TP
.B delay_first_probe_time
˵ۥȤΥȥ꤬ŤʤäȽǤ줿
ǽõԤޤǤٱ֡ǥեȤ 5 á
.TP
.B gc_interval
١쥯˵ۥȥȥФƼ¹Ԥ١
ǥեȤ 30 á
.TP
.B gc_stale_time
Ťʤä˵ۥȥȥФƥåԤ١
˵ۥȥȥ꤬ŤʤäȤߤʤȡΥȥ
ǡˤϺٲ褬Ԥ롣
ǥեȤ 60 á
.TP
.B gc_thresh1
ARP å¸륨ȥκǾ͡
ο꾯ʤȥꤷåˤʤС
١쥯ϼ¹Ԥʤ
ǥեȤ 128
.TP
.B gc_thresh2
ARP å¸륨ȥΥեȤʺ͡
åΥȥ꤬ο 5 ôֱۤĤŤȡ
١쥯¹Ԥ롣
ǥեȤ 512
.TP
.B gc_thresh3
ARP å¸륨ȥΥϡɤʺ͡
åΥȥ꤬οۤȡ
١쥯Ϥ˼¹Ԥ롣
ǥեȤ 1024
.TP
.B locktime
ARP ȥ򥭥å¸֤κǾ (jiffy ñ)
ǽΤޥåԥ󥰤İʾ夢 (ƤϥͥåȥΥߥ)
ˡ ARP åΥå󥰤뤳Ȥɤ
ǥեȤ 1 á
.TP
.B mcast_solicit
ȥ unreachable ޡˡ
ɥ쥹ޥ㥹/֥ɥ㥹ȤDz褷褦Ȥ
Բκ͡
ǥեȤ 3
.TP
.B proxy_delay
Τ ARP ɥ쥹Ф ARP ꥯȤˡ
˺
.I proxy_delay
jiffy ޤٱ䤹롣Ͼˤä
ͥåȥեåǥ (network flooding) 򤱤뤿Ѥ롣
ǥեȤ 0.8 á
.TP
.B proxy_qlen
 ARP ɥ쥹Фƥ塼󥰤ǤΥѥåȿ
ǥեȤ 64
.TP
.B retrans_time
ꥯȤޤǤٱ (jiffy ñ)
ǥեȤ 1 á
.TP
.B ucast_solicit
ARP ǡؤ䤤碌Ԥ˹Ԥ unicast õκԿ
.RI ( app_solicit
򸫤)ǥեȤ 3
.TP
.B unres_qlen
褵Ƥʤɥ쥹Фơ
¾Υͥåȥؤ饭塼󥰤Ǥѥåȿ
ǥեȤ 3
.SH С
Linux 2.0 ǡ
.I struct arpreq

.I arp_dev
Сޤޤ褦ѹäޤƱ
ioctl ֹѹ줿Ť ioctl 
Linux 2.2 Ѥ뤳ȤǤʤʤä

ͥåȥФ arp ȥ (netmask  0xffffffff Ǥʤ)
ϡ Linux 2.2 Ѥ뤳ȤǤʤʤä
ϥͥˤäꤵ롢̤Υ󥿡եˤ
ãǽʤ٤ƤΥۥȤФ뼫ư arp ˤä֤줿
(Υ󥿡եǥեǥ󥰤 arp ͭˤʤäƤ)

.I neigh/*
γ sysctl  Linux 2.2 ˤ¸ߤʤ
.SH Х
ĤΥޡ jiffy ǻꤵ뤬
jiffy ϥƥ䥫ͥΥС˰¸롣
.BR time (7)
򻲾ȤΤȡ
.PP
桼֤ݥƥ֤ʥեɥХåˡ¸ߤʤ
Ĥޤ³ظ (connection oriented) Υץȥ桼֤
ȡ;פ ARP ȥեåθȤʤ롣
ʤʤ ndisc Ū MAC ɥ쥹õ뤫Ǥ롣
ƱͤϤĤΥͥץȥ (NFS over UDP ʤ) ˤ¸ߤ롣
.PP
 man ڡǤ IPv4 ͭεǽ
IPv4IPv6 Ƕͭ뵡ǽȤäˤʤäƤ롣
.SH Ϣ
.BR capabilities (7),
.BR ip (7)
.PP
.BR RFC\ 826 :
ARP ˴ؤ
.br
.BR RFC\ 2461 :
IPv6 neighbor discovery ˴ؤȡ
ѤƤå르ꥺ
.LP
Linux 2.2 ʹߤ IPv4 ARP ϡ
ǽʾ IPv6 Υ르ꥺѤ롣