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Á¦¸ñ BridgeÀÇ ±âÃÊ¹× µ¿ÀÛ ¹æ½Ä
ÀÛ¼ºÀÚ jackki
ÀÛ¼ºÀÏÀÚ 2022-03-23
µ¿ÀÏÇÑ Frame¸¸À» Àü¼ÛÇϹǷΠµ¿ÀÏÇÑ Network Number¿Í Access ProtocolÀÌ °°Àº
Network¸¸À» ¼­·Î ¿¬°áÇÑ´Ù. ¶ÇÇÑ OSIÀÇ Data Link°èÃþÀÇ ±â´ÉÀ» ¼ö¿ëÇÑ´Ù.


Frame ó¸® ¹æ½Ä¿¡ µû¸¥ BridgeÀÇ ±¸ºÐ


Transparent Bridge(Spanning Tree)
IEEE 802.3 Frame¸¸ °¡´ÉÇϸç Frame³»¿¡ ¾î¶² routingÁ¤º¸µµ Æ÷ÇÔÇÏÁö ¾Ê°íÀÖ´Ù.
µ¿ÀÏ segments³»¿¡ ÀÖ´Â frameµéÀº Bridge·Î copyµÇ¸ç Bridge´Â Routing TableÀ»
È®ÀÎÇÏ¿© frameÀÇ Forwarding°ú FilteringÀ» °áÁ¤ÇÑ´Ù. ºê¸®Áö´Â statically ¶Ç´Â
dynamicallyÇÏ°Ô »ý¼ºµÉ ¼ö ÀÖ´Â Routing TableÀ» ÇÊ¿ä·Î ÇÑ´Ù.
 
Static Routing Table : ¼³Ä¡ Àü »çÀü Á¤ÀÇ
Dynamic Routing Table : Bridge°¡ óÀ½ ¼³Ä¡µÈ ÈÄ ¸Å 30Ãʸ¶´Ù °¢ segmentÀÇ active
address¸¦ learnÇÑ´Ù. ¶ÇÇÑ ÀÏÁ¤ÇÑ ½Ã°£ µ¿¾È ¹ÝÀÀÀÌ ¾ø´Â node¿¡ ´ëÇؼ­´Â
ºê¸®ÁöÀÇ È¿À²À» ³ôÀ̱â À§ÇØ table entry¿¡¼­ »èÁ¦ÇÑ´Ù.


Source Route Bridge
IEEE 802.5¸¸ °¡´ÉÇϸç FrameÀÇ RIF(Routing Information Field)¸¦ ÀÌ¿ëÇÏ¿©
source¿Í target node°£ÀÇ best path¸¦ °áÁ¤ÇÑ´Ù. ºê¸®Áö°¡ MACÁÖ¼Ò¿Í dataºÎºÐÀ»
¹«½ÃÇÏ¿© ¾î¶² routingÁ¤º¸µµ Æ÷ÇÔÇÏÁö ¾ÊÀ¸¹Ç·Î source¿Í target node°¡ ±× path¸¦ ±â¾ïÇÑ´Ù.


ROUTE DISCOVERY PROCESS


All-Routes Broadcast Routing
Source ³ëµå´Â route discovery frameÀ» sendÇÏ°í ±×°ÍÀº ¸ðµç ºê¸®Áö¸¦ ÅëÇÏ¿©
Àü¼ÛµÇ¸ç RIF¿¡ °æ·Î¸¦ Àû´Â´Ù. Target node´Â Çϳª ÀÌ»óÀÇ route discovery frameÀ»
¹ÞÀ¸¸ç ±×°ÍµéÀ» ´Ù½Ã º¸³½´Ù. source´Â receiveµÈ respondµéÀ» ÀÌ¿ëÇØ ÃÖÀûÀÇ °æ·Î¸¦ ¼³Á¤ÇÑ´Ù.


Single-Route Broadcast Routing
route discovery frameÀ» º¸³»µÇ µÎ ³ëµå°£¿¡´Â ´ÜÀÏ path¸¸ Á¸ÀçÇϵµ·Ï ÇÑ´Ù.
Áï, target ³ëµå´Â ´Ü ÇϳªÀÇ route discovery frame¸¸À» ¹Þ´Â´Ù. ´Ù½Ã target ³ëµå´Â
all-routes broadcastÇϸç source´Â receiveµÈ respondµéÀ» ÀÌ¿ëÇØ ÃÖÀûÀÇ °æ·Î¸¦ ¼³Á¤ÇÑ´Ù.




Spanning Tree


ÁÖ¾îÁø LAN°£¿¡´Â ´Ü ÇϳªÀÇ active path¸¸ÀÌ Á¸ÀçÇϵµ·Ï ÇÏ´Â Logical Topology·Î¼­
IBM¿¡¼­ Recomment Mechanics


1. Establish a root Bridge ¸ðµç Bridge´Â ±×µéÀÌ bootµÉ ¶§, Bridge Priority¸¦ AdvertiseÇϸç
°¡Àå »óÀ§ÀÇ Priority°¡ root°¡ µÈ´Ù.


2. ¾î¶² Bridge port°¡ Blocked stateÀÎÁö ¶Ç´Â forwarding stateÀÎÁö¸¦ °áÁ¤, °¢ Bridge´Â Root
Bridge·Î path cost¸¦ advertising BPDU(Bridge Protocol Data Unit)¸¦ Àü¼ÛÇÑ´Ù.


¸¸¾à Bridge°¡ ÀڱⰡ advertisingÇÑ °Íº¸´Ù ´õ ÇÏÀ§ path costÀÇ BPDU¸¦ ¹Þ´Â´Ù¸é ÇÏÀ§ÀÇ Bridge´Â
Blocked state°¡ µÈ´Ù.


¸¸¾à Bridge°¡ ÀڱⰡ advertisingÇÑ °Í°ú µ¿ÀÏÇÑ path costÀÇ BPDU¸¦ ¹Þ´Â´Ù¸é port priority value¸¦
checkÇÏ¸ç ¸¸¾à ÀÚ±âÀÇ priorityº¸´Ù ´õ Å©´Ù¸é ±× port¿¡ ´ëÇØ Blocked state°¡ µÈ´Ù.


¸¸¾à path cost¿Í port priority value°¡ µ¿ÀÏÇϸé MAC ÁÖ¼Ò¸¦checkÇÑ´Ù.
ÇÏÀ§ÀÇ ÁÖ¼Ò´Â forwardingÀÇ »óÅ°¡ µÈ´Ù.


¸¸¾à Transeparent Bridging ȯ°æ¿¡¼­ Spanning Tree¸¦ »ç¿ëÄ¡ ¾Ê´Â´Ù¸é `Closed Loop' ¹ß»ýÇϸç
Blocked Bridge´Â path cost¿Í °°Àº Á¤º¸¸¦ updateÇϳª ´ÜÁö È°µ¿¸¸ ¾ÊÇÏ°í ÀÖÀ» »ÓÀÌ´Ù.
¶ÇÇÑ Forwarding Bridge°¡ Down½Ã¿¡´Â ±× ¾÷¹«¸¦ ´ë½ÅÇÑ´Ù.