ͥåȥڥꥹ - SE̼η -

ͥåȥڥꥹȤλкȤǤͥåȥڥꥹȻι
̡ʤΥġ⡢μʤɤξǺܤޤкߥʡԤäƤޤ ͥåȥڥꥹ
кʤ麸κǤܤ֥ͥڡץ꡼ʵɾҡˤǡ
ͥåȥڥꥹȻ˹ʤȡͥåȥ˴ؤμ䵻ѤǤʤɲϤʸϤȤˤĤޤ
ˡλ˹ʤǤȤ뤳ȤǤޤ

ƥꡧ7.ءL1,L2 > 7.6.1 STP

⤽⡢ʤSTPɬפʤΤ
д
ʬޤ
֤BPDU(Bridge Protocol Data Unit)Ȥꤹ뤳Ȥǡ롼פɤᡣ롼פȯȡͥåȥԾ֤ˤʤäơ̿ǤʤǤ
ΤȤꡣ
LAN߷פ򤹤Ȥˡƥ롼פ뤳ȤŪǤ롣ʤ
ϡ롼׹ȤǡSTPͭˤƤС㳲ˤϤΥ롼פϩˤʤ뤫⡢㳲ˤϼưŪSTPκƷ׻äơϩ˼ưڤؤƤ뤫Ǥ롣
CSTǤϡڤؤΥС󥹡ʼ«ˤ40äۤɤäƤRSTPʤɤǤϡäڤؤ롣

STPŪȼ2Ĥˤʤ롣

STPŪ
롼פβ
ʾĹγݡ

Ǥϡѥ˥󥰥ĥ꡼εǽ򡢡ʣΥ֥å֤Ǿ򴹤礤롼ȯ㳲α롼ȷԤʿ17ǯ١44ˡסBPDUȸƤФե졼ꤷ̿Υ롼פ򤹤ץȥ롣ʿ21ǯ١11ˡפȽҤ٤Ƥޤ

ǥå
STPˤǥåȤ⤢ޤϡPC³Ƥľ̿ǽʾ֤ˤʤʤH21NW113(3)פȤǤ
STPͭSwitchingHUBPC³Ƥ⡢IEEE802.1Dˤ̾STPξ硢BPDUΤȤ꤬ԤΤǡ³ޤǤ40äۤɤäƤޤ

PCHUBSTPͭSWDHCP

Ȥξ硢PCDHCPˤIPɥ쥹׵ᤷƤ⡢STPͭSW󥯥åפ줺DHCPФIPɥ쥹ǤʤȤ꤬ȯ뤳Ȥ⤢롣

STP̵
åΤ̵ˤno spanning-tree protocol)ȡݡñ̵̤ˤ(portfast)礬롣嵭ǽ񤤤褦򤹤뤿ˡPC³ݡȤˤϡportfast뤳Ȥޤ

ʲϾǤϽꤵʤȻפޤΤǻ٤

ѥ˥󥰥ĥ꡼μ
STPSpanning Tree ProtocolˡIEEE 802.1Dǵ Dʸ
PVSTPer VLAN Spaninng TreeˡVLANȤSpaninng TreeCiscoǤPVST+
RSTPRapid Spanning TreeˡIEEE 802.1wڤؤ®STPߤIEEE802.1D礵Ƥ롣CSTPξ硢ȥݥѹäȤTCN(Topology Change NotificationBPDUΤ餻Ʒ׻򥹥Ȥ롣RSTPǤTCN BPDUͥåȥΤ뤳ȤϤѹɬפʥåľܤȤHandshakeˤԤȤǡ®Ƥ롣󥯥ʤɤǤϤʤ󥯥åפ䵡郎ɲä줿ϡΤκƷ׻ɬפʤΤǡ̾STPƱͤμ«֤ɬס
MSTPMultiple Spanning Tree ProtocolˡIEEE802.1sPVSTVLANȤSTPVLANƤȡ줾STP٤롣ǡVLANޤȤƥ󥹥󥹤Ȥ롼פꡢΥ롼פSTPꤹ롣


119Υƥȥ֥ϡSTP򤷤ʤä˥롼פ򵯤ȤΤ褦֥ƥ㳲ϤʤٵסBPҡˤϡ2011ǯɼ֤ߵ޼֤νưٱ礹ģξ󥷥ƥब󤷡119󤬤Ĥʤˤʤ֤ȯϰܤLAN֥θ³ˤä̿Ρ֥롼ספȯȡͽƥⵡǽƶͻȾ˵ڤפȽҤ٤Ƥ롣

֥åݡȤη
롼ȥ֥åϡͥåȥξ֤ʬ濴Ȥĥ꡼¤Ȥİ롣
ֳ֤BPDU(Bridge Protocol Data Unit)ѥåȤ򴹤롣롼ȥ֥åʳžRSTPǤåߤ˸򴹤ȤߤȤʤꡢ®ʼ«ǽˤƤ롣
ǾΥ֥åIDʥץ饤ƥMACɥ쥹ˤĵ郎롼ȥ֥åǥեȤΥץ饤ƥ32768
BID8byteˡ=[ ץ饤ƥ(2byte)][ MACɥ쥹6byteˡ ǹ뤿ᡢMACɥ쥹ץ饤ƥͥ褵롣
ơϡ֥å(20)ꥹ˥(15)顼˥(15)եǥ
RSTP(802.1w)Ǥϥ֥å󥰤ꥹ˥󥰤ޤȤƥǥǥ󥰤ȤƤ롣
֥å󥰥ݡȡݡȡˤη
1)ƥåǡ롼ȥ֥å˺ǤᤤݡȤ롼ȥݡ
2)ƥȡʵȵĤʤˤǡ롼ȥ֥å˺ǤᤤݡȤݡ
3)ʳ֥å˥ݡȤǥ֥å롣

ºݤˤϷ빽ץ롣롼ȥ֥å˺Ǥ󤤤Ȥ֥å

ˤ
STPˤϩ˴ؤ꤬ΤǾҲ𤹤롣
H20NW44
ޤϡ쥤2åˤäơѥ˥󥰥ĥ꡼ץȥѤƹLAN򼨤ƥå˥֥åץ饤ƥͤѥȤ10Mӥå/åݡȤ100100Mӥå/åݡȤ19ꤵƤ롣PC1PC2̿˻ѤϩϤɤ줫ǡi,j,kϤ줾Ʊͤ򼨤


stp
4Ǥ뤬ʬθդDzͤƤۤ

򡧥åA-C-B

H20NW14ˤϡSWΥ֥åΥץ饤ƥη䤦꤬ä
֥å줿ݡȡNDPˤǤϡե졼žϹԤʤ
ϥƥ

NDPΤĤʤäƤξNDPȤƥ֥åƤϡ
ɤ̿ϤʤǤ硣
NDPBPDUμ򤹤뤬⤷ʤBPDU򴹤ʤȡSTPΥȥݥѹбǤʤʤΤǡξNDPˤΤǤϤʤϡBPDUDPˤ롣

ʿ25ǯNW孶1ˤ򤤤Ƥߤ褦
L2SWL3SWǤ,  STP (Spanning Tree Protocol)ưƤ롣L3SW1롼ȥ֥åȤ뤿ˡL3SW1Υ֥åIDϡ̡ͤͤȤʤäƤ롣

ѥ˥󥰥ĥ꡼ϡդ̤ĥ꡼tree˹¤ˤʤäƤޤΥĥ꡼¤κrootˡĤޤ굯ˤʤΤ롼ȥ֥åǤ롼ȥ֥åȤʤ뤿ˤϥ֥åIDɤΤ褦ͤǤ٤Ƥޤ롼ȥ֥åȤФΤϡǾΥ֥åIDꤵ줿åȷƤޤ

Ǿ


IEEE802.1s
PVSTVLANȤSTPVLANƤȡ줾STP٤롣ǡVLANޤȤƥ󥹥󥹤Ȥ롼פꡢΥ롼פSTPꤹ롣

H24ǯNW孶2ˤ򸫤Ƥߤ褦
STPĴȤꤷSTPϡĥ꡼VLANȤ˹ǤʤȤʬäܤĴ٤ȡVLANȤ˥ĥ꡼뤿ˤ.  IEEE802.1sǵꤵƤMSTP Multiple spanning Tree Protocol)ȤȤɬפǤä
MSTPϡʣVLAN򥤥󥹥󥹤ȸƤФ륰롼פˤޤȤᡤ󥹥ñ̤ǥѥ˥󥰥å꡼η׻ԤΤȤ󥹥󥹤Ȥ˥롼ȥ֥åڤӥ֥å󥰥ݡȤꤵ졤󥹥ñ̤˥ĥ꡼롣

ʿ17ǯ١44
ѥ˥󥰥ĥ꡼εǽΤϤɤ줫

MACɥ쥹򸫤ơե졼Ѵ뤫Ѥ뤫롣
̿ԤƤʤMACɥ쥹MACɥ쥹ơ֥뤫õ롣
ϩʣ¸ߤ硢ץꥱ䥢ɥ쥹Ȥ˷ϩ򿶤ʬơ٤ʬ롣
ʣΥ֥å֤Ǿ򴹤礤롼ȯ㳲α롼ȷԤ

򡧥

H29NW
5ѥ˥󥰥ĥ꡼ץȥ˴ؤ뵭ҤΤŬڤʤΤϤɤ줫
OSIܻȥǥˤͥåȥؤΥץȥǤ롣
֥å֤ʣϩ硤Ʊ˥ե졼ž뤳ȤǽˤץȥǤ롣
֥ɥ㥹ȥե졼򡤥֥å֤žʤ롣
롼ȥ֥åηˤϡ֥å̤ͥMACɥ쥹Ѥ롣

򡧥



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