'\" 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 1999-12-06, NAKANO Takeo <nakano@apm.seikei.ac.jp>
.\" Updated & Modified 2001-02-16, NAKANO Takeo
.\" Updated 2008-12-26, Akihiro MOTOKI, LDP v3.14
.\"
.\"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 2008-11-25 "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 AF_INET
åȤ
.BR ioctl (2)
Ѥ롣
.PP
ARP ⥸塼ϥϡɥɥ쥹ץȥ륢ɥ쥹ؤ
ޥåԥ󥰤Υå롣å礭ˤ¤
ΤǡŤȥѤʤȥϥ١쥯
롣 permanent (¸) ޡĤ줿ȥϡ
褷ƥ١쥯ˤäƾõʤ
ioctl ѤХåľ뤳ȤǤ롣
ޤҤ
.I /proc
󥿥եˤꥭåο񤤤ĴǤ롣
.PP
¸ߤƤޥåԥ󥰤Фơ
ΥեɥХå֤ʤ (Ҥ
.I /proc
󥿥ե򸫤) 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 AF_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 /proc 󥿥ե
ARP ǤϡХʥѥ᡼䥤󥿡եȤΥѥ᡼
.I /proc
󥿥ե̤ꤹ뤳ȤǤ롣
Υ󥿥եˤϡ
.I proc/sys/net/ipv4/neigh/*/*
եɤ߽񤭤ˤꥢǤ롣
ƥˤ뤽줾Υ󥿡եˤϡ
줾бǥ쥯ȥ꤬
.I /proc/sys/net/ipv4/neigh/
ʲˤ롣
"default" ǥ쥯ȥФ򤹤ȡ
ʹǥХƤФƤ꤬Ѥ롣
ä˻꤬ʤС֤˴ؤ sysctl ñ̤äǤ롣
.TP
.IR anycast_delay " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
IPv6 ζ˵å (neighbor soliciation message)
˱ޤǤκٱ (jiffy ñ)
anycast ΥݡȤϤޤƤʤ
ǥեȤ 1 á
.TP
.IR app_solicit " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
桼֤ ARP ǡ netlink Ѥõ
ۤȥޥ㥹Ȥˤõ˰ܹԤ
.RI ( mcast_solicit
򸫤)
.TP
.IR base_reachable_time " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
˵ΥۥȤߤĤȡΥȥ
.IR base_reachable_time "/2  3*" base_reachable_time /2
δ֤Υͤλ֡ͭǤȤߤʤ롣
ȥͭϡ̤Υץȥ뤫ݥƥ֤ʥեɥХå
ȱĹ롣ǥեȤ 30 á
Υեϸߤ侩Ǥꡢ
.I base_reachable_time_ms
Ȥȡ
.TP
.IR base_reachable_time_ms " (Linux 2.6.12 ʹ)"
.I base_reachable_time
Ʊ֤ߥñ̤¬롣
ǥեȤ 30000 ߥäǤ롣
.TP
.IR delay_first_probe_time " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
˵ۥȤΥȥ꤬ŤʤäȽǤ줿
ǽõԤޤǤٱ֡ǥեȤ 5 á
.TP
.IR gc_interval " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
١쥯˵ۥȥȥФƼ¹Ԥ١
ǥեȤ 30 á
.TP
.IR gc_stale_time " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
Ťʤä˵ۥȥȥФƥåԤ١
˵ۥȥȥ꤬ŤʤäȤߤʤȡΥȥ
ǡˤϺٲ褬Ԥ롣
ǥեȤ 60 á
.TP
.IR gc_thresh1 " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
ARP å¸륨ȥκǾ͡
ο꾯ʤȥꤷåˤʤС
١쥯ϼ¹Ԥʤ
ǥեȤ 128
.TP
.IR gc_thresh2 " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
ARP å¸륨ȥΥեȤʺ͡
åΥȥ꤬ο 5 ôֱۤĤŤȡ
١쥯¹Ԥ롣
ǥեȤ 512
.TP
.IR gc_thresh3 " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
ARP å¸륨ȥΥϡɤʺ͡
åΥȥ꤬οۤȡ
١쥯Ϥ˼¹Ԥ롣
ǥեȤ 1024
.TP
.IR locktime " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
ARP ȥ򥭥å¸֤κǾ (jiffy ñ)
ǽΤޥåԥ󥰤İʾ夢 (ƤϥͥåȥΥߥ)
ˡ ARP åΥå󥰤뤳Ȥɤ
ǥեȤ 1 á
.TP
.IR mcast_solicit " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
ȥ unreachable ޡˡ
ɥ쥹ޥ㥹/֥ɥ㥹ȤDz褷褦Ȥ
Բκ͡
ǥեȤ 3
.TP
.IR proxy_delay " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
Τ ARP ɥ쥹Ф ARP ꥯȤˡ
˺
.I proxy_delay
jiffy ޤٱ䤹롣Ͼˤä
ͥåȥեåǥ (network flooding) 򤱤뤿Ѥ롣
ǥեȤ 0.8 á
.TP
.IR proxy_qlen " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
 ARP ɥ쥹Фƥ塼󥰤ǤΥѥåȿ
ǥեȤ 64
.TP
.IR retrans_time " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
ꥯȤޤǤٱ (jiffy ñ)
ǥեȤ 1 á
Υեϸߤ侩Ǥꡢ
.I retrans_time_ms
Ȥȡ
.TP
.IR retrans_time_ms " (Linux 2.6.12 ʹ)"
ꥯȤޤǤٱ (ߥñ)
ǥեȤ 1000 ߥá
.TP
.IR ucast_solicit " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
ARP ǡؤ䤤碌Ԥ˹Ԥ unicast õκԿ
.RI ( app_solicit
򸫤)ǥեȤ 3
.TP
.IR unres_qlen " (Linux 2.2 ʹ)"
.\" Precisely: 2.1.79
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/*
γƥ󥿥ե 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