Bridging mini-Howto Christopher Cole, cole@coledd.com v1.21, March 7, 2001 Â÷ÇÑÁø maylinux@korea.com 2001³â 3¿ù 19ÀÏ ÀÌ ¹®¼­´Â Ethernet bridge ¼³Á¤ÇÏ´Â ¹æ¹ýÀ» ¼³¸íÇϰí ÀÖ´Ù. Ethernet bridge¶õ ¹«¾ùÀΰ¡? ¸¹Àº ¾çÀÇ µ¥ÀÌÅÍ ºñÆ®ÀÇ ¼ÒÅë·®À» ³ª´©´Â ¼­ºê³ÝÀÇ µ¥ÀÌÅÍ ÆÐŶÀ» ĿƮ·Ñ ÇÏ´Â ÀåÄ¡ÀÌ´Ù. Bridge ´Â °°Àº ±×·ì¾ÈÀÇ ´Ù¸¥ ÄÄÇ»ÅÍ »çÀÌ¿¡ Ç×»ó Á¸ÀçÇÑ´Ù. ÇÏÁö¸¸ ´Ù¸¥ ±×·ì¿¡ ÀÖ´Â ÄÄÇ»ÅͱîÁö Æ÷ÇÔÇÏÁö´Â ¾Ê´Â´Ù. ÁÁÀº ¿¹·Î ¸ÆÄËÅä½ÃÀÇ Å©·¯½ºÅÍ¿Í À¯´Ð½ºÀÇ Å©·¯½ºÅ͸¦ µé¼ö ÀÖ´Ù. ±× ¸Ó½ÅµéÀº ±×µé ÀÇ»ç¼ÒÅëÀ» ÇϰÔÇÑ´Ù, ±×¸®°í µ¥ÀÌÅÍ ¼ÒÅëÀº °¢ ¸Ó½Å°£ÀÇ ¼ÒÅë¿¡ ÀÇÇÑ µ¥ÀÌÅÍ Ãæµ¹(collisions)ÀÌ ÀϾ´Â À©ÀÎÀ» ¸¸µé¾î³½´Ù. Bridge ´Â µ¥ÀÌÅÍ ÆÐŶÀÌ µµÂøÇÒ ¸ñÀûÁö¿Í Ç༱Áö¸¦ °ËÅäÇÏ°í ´Ù¸¥ ÀÌ´õ³Ý ¼¼Å©¸ÕÆ®¸¦ °æÀ¯ÇÒ°ÍÀÎÁö ¾È ÇÒ°ÍÀÎÁö °áÁ¤ÇÏ´Â ÀÏÀ» ÇÑ´Ù. ±× °á°ú ³×Æ®¿öÅ©¸¦ ´õ ºü¸£°í ¾ÈÁ¤¼º ÀÖÀ¸¸ç Ãæµ¹À» ÁÙÀϼö ÀÖ´Ù. ¿ªÀÚ...Bridge ´Â °¢ ³×Æ®¿öÅ©¸¦ ¿¬°áÇÏ´Â ÀåÄ¡, ¹æ¹ýÀ» ÀÏÄÖ´Â ¸»·Î ±»ÀÌ º¯¿ªÇÏÁö ¾Ê°í Bridge ¶ó´Â ´Ü¾î¸¦ ½èÀ½À» ¾Ë·Áµå¸³´Ï´Ù..±×¸®°í ¿ÀŸ³ª ¿À¿ªÀÌ ÀÖÀ¸¸é ¸ÞÀÏÀ» º¸³»Áֽñ⠹ٶø´Ï´Ù. ______________________________________________________________________ ¸ñÂ÷ 1. ¼³Ä¡ 2. º¸ÆíÀûÀÎ ¹®Á¦µé ______________________________________________________________________ 1. ¼³Ä¡ 1. ``Bridge Config''¸¦ ±¸ÇÑ´Ù. BRCFG´Â http ¿¡¼­µµ ±¸ÇÒ¼ö ÀÖ´Ù. 2. º¹¼öÀÇ ÀÌ´õ³ÝÀåÄ¡¸¦ »ç¿ëÇÒ¼ö ÀÖµµ·Ï /etc/lilo.conf¿¡ ´ÙÀ½°ú °°ÀÌ Ãß°¡Ç϶ó. ±×¸®°í lilo¸¦ Àç½ÇÇà½ÃÄѶó. append = "ether=0,0,eth1" ¸¸ÀÏ ´ç½ÅÀÌ ¼¼°³ÀÇ ÀÌ´õ³ÝÀåÄ¡¸¦ °¡Áö°í ÀÖ´Ù¸é, ´ÙÀ½ ¶óÀÎÀ¸·Î ´ë½ÅÇ϶ó. append = "ether=0,0,eth1 ether=0,0,eth2" ´õ ¸¹Àº ÀåÄ¡°¡ ÀÖ´õ¶óµµ °°Àº ¹æ½ÄÀ¸·Î Ãß°¡ ÇÒ¼ö ÀÖ´Ù. ±âº»ÀûÀ¸·Î ¸®´ª½ºÄ¿³ÎÀº ÇѰ³ÀÇ ÀÌ´õ³ÝÄ«µå¸¦ Áö¿øÇÏ°Ô µÇ¾îÀÖ´Ù. À§¿Í °°Àº append ¼³Á¤À¸·Î ¸¹Àº ÀÌ´õ³ÝÄ«µå¸¦ Áö¿øÇÏ°Ô ÇÒ¼ö ÀÖ´Ù. ¶Ç ´Ù¸¥ ¹æ¹ýÀ¸·Îµµ ÆÄ¶ó¹ÌÅ͸¦ ¼³Á¤ÇÒ¼ö ÀÖ´Ù. linux ether=0,0,eth1 ¸¸ÀÏ ¼¼°³ÀÇ ÀåÄ¡¶ó¸é: linux ether=0,0,eth1 ether=0,0,eth2 3. BRIDGINGÀÌ °¡´ÉÇϵµ·Ï Ä¿³ÎÀ» ÀçÄÄÆÄÀÏÇÏ¿©¶ó. 4. bridge´Â IP address ¸¦ ²À ÇÊ¿äÇÑ°Ç ¾Æ´Ï´Ù. ÀϹÝÀûÀÎ bridge ¿¡¼­´Â Çʿ䰡 ¾ø´Ù. ³ÊÀÇ bridge ¿¡¼­ IP address Á¦°ÅÇ϶ó. ±×¸®°í /etc/sysconfig/network-scripts/ (for a RedHat system)·Î À̵¿Ç϶ó. ±×¸®°í ifcfg-lo0¸¦ ifcfg-eth0 ¿Í ifcfg-eth1·Î º¹»çÇ϶ó. 2°³ÀÇ ÆÄÀϾÈÀÇ "DEVICE=lo"' À» "DEVICE=eth0" ¿Í "DEVICE=eth1"·Î º¯°æÇ϶ó. ´Ù¸¥ ¹èÆ÷ÆÇ¿¡ µû¶ó ¾à°£ ´Ù¸¦¼ö ÀÖ´Ù. ÇÏÁö¸¸ Å©°Ô ´Ù¸£Áö ¾ÊÀ¸´Ï ¼³Á¤¿¡ ¾î·Á¿òÀ» ¾øÀ» °ÍÀÌ´Ù. 2°³ÀÌ»óÀÇ ÀÌ´õ³ÝÀåÄ¡°¡ ÀÖ´Ù¸é ¾Õ¿¡¼­ ¾ð±ÞÇÑ ¹Ù¿Í °°ÀÌ ¼³Á¤ÇÏ¸é µÈ´Ù. 5. ÀçºÎÆÃ, ±×¸®°í bridging ÀÌ µÈ »õ·Î¿î Ä¿³Î·Î ½ÇÇàÇØ¾ßÇÑ´Ù. ±×·¯¸é ³×Æ®¿öÅ© ÀÎÅÍÆäÀ̽º»ó¿¡ °æ°è°¡ ¾ø´Â IP ¾îµå·¹½º¸¦ ¾ò°Ô µÉ°ÍÀÌ´Ù. 6. ½Ã½ºÅÛ¿¡¼­ ¹é¾÷ÇØµÐ °ÍÀ» ÀÌ´õ³ÝÄ«µå¼³Á¤¿¡ ´Ù½Ã Àû¿ëÇÑ´Ù. (¹°·Ð óÀ½ºÎÅÍ ´Ù½Ã ¼³Á¤Çصµ µÇ°ÚÁö¸¸, Á¶±Ý ±ÍÂúÀ¸´Ï) ±×·¯¸é ´ç½ÅÀº ±× ÀåÄ¡¸¦ Åë°úÇÏ´Â ¸ðµç ÆÐŶÀ» º¼¼ö ÀÖ´Ù. ifconfig eth0 promisc ; ifconfig eth1 promisc Bridge ³×Æ®¿öÅ©¿¡ ¿¬°áµÈ ¸ðµç ÀåÄ¡µéÀº ¼³Á¤À» À§¿Í °°ÀÌ ÇØ¾ßÇÑ´Ù. 7. brcfg ÇÁ·Î±×·¥ÀÌ »ç¿ë°¡´ÉÇϵµ·Ï enable ½ÃŲ´Ù. brcfg -ena 8. °¢ ÀåÄ¡¿¡¼­ µ¥ÀÌÅͼÒÅëÀ» È®ÀÎÇ϶ó. tcpdump -i eth0 (in one window) tcpdump -i eth1 (in another window) 9. ´Ù¸¥ ¸Ó½Å¿¡¼­ sniffer¸¦ ½ÇÇàÇϰųªtcpdump·Î bridge °¡ ¼¼±×¸ÕÆ®¸¦ Á¤È®È÷ ºÐ·ùÇÏ´Â È®ÀÎÇ϶ó. 2. º¸ÆíÀûÀÎ ¹®Á¦µé 1. Question ´ÙÀ½°ú °°Àº ¸Þ¼¼Áö°¡ Ãâ·ÂµÆ´Ù. ioctl(SIOCGIFBR) failed: Package not installed ÀÌ°Ç ¹«½¼ ÀǹÌÀΰ¡?? Answer ´ç½ÅÀÇ Ä¿³Î¿¡¼­ bridging ´É·ÂÀ» Áö¿øÀ» ÇÏÁö ¸øÇÑ °ÍÀÌ´Ù. 2.0 ÀÌ»óÀÇ Ä¿³ÎÀ» ´Ù¿î¹Þ¾Æ¼­, BRIDGING ÀÌ °¡´ÉÇϵµ·Ï Àç ÄÄÆÄÀÏÇ϶ó. 2. Question ÇÑÂÊ ¸Ó½Å¿¡¼­ ´Ù¸¥ ¸Ó½ÅÂÊÀ¸·Î pingÀ» ÇÒ¼ö ¾ø´Ù. Answer o ´ç½ÅÀº "brcfg -ena"À» ½ÇÇàÇߴ°¡? (brcfg °¡ "bridging is ENABLED")¸¦ Ãâ·ÂÇØ¾ßÇÑ´Ù. o ÀåÄ¡¿¡ ¸ðµå¼³Á¤À» ÇÏ¿´´Â°¡? "ifconfig" ¸í·É¾î°¡ ÇÙ½ÉÀÌ´Ù. "PROMISC" Ç¥½Ã°¡ ÀåÄ¡ ¸ðµÎ¿¡¼­ ³ªÅ¸³ª¾ß ÇÑ´Ù. o ¿©·¯°³ÀÇ ÀåÄ¡ ¾î´ðÅ͸¦ »ç¿ëÇÑ´Ù¸é ¿Ã¹Ù¸¥ Çϳª¸¸À» »ç¿ëÇØ¾ß ÇÑ´Ù. ±×¸®°í ±× ³×Æ®¿öÅ© ÀåÄ¡¿¡ ´ëÇØ ¼³Ä¡¿Í ¼³Á¤À» ÇØ¾ßÇÑ´Ù. 3. Question telnet/ftp ¸¦ bridge·Î ºÎÅÍ ¿¬°áÇÒ¼ö ¾ø´Ù. Answer IP address ¹Ù¿îµùÀÌ ¾î¶² bridge ·Î ºÎÅ͵µ ¾ø¾ú±â ¶§¹®ÀÌ´Ù. bridgeµµ ³×Æ®¿öÅ©ÀÇ ÀÏÁ¾ÀÌ´Ù.. 4. Question ¶ó¿ìÆÃ °æ·Î¿¡ ´ëÇÑ ¼³Á¤À» ÇØ¾ßÇϳª? Answer Nothing! ¸ðµç ¶ó¿ìÆÃ Á¤º¸´Â Ä¿³ÎÀÇ Bridging Äڵ忡 Á¿ìµÈ´Ù. ´ç½ÅÀº Bridge¿¡ ´ëÇØ ¹è¿î ÀÌ´õ³Ý ¾îµå·¹½ºµéÀ» brcfg ÇÁ·Î±×·¥ÀÇ µð¹öµå ¸ðµå·Î º¼¼ö ÀÖ´Ù. brcfg -deb 5. Question Bridge ¿¡ ÀÇÇÑ ÀÛ¾÷Àº "traceroute" ¿¡ º¸ÀÌÁö ¾Ê´Â°¡? Answer º»ÁúÀûÀ¸·Î Bridge´Â "traceroute" ¿¡ º¸ÀÌÁö ¾Ê´Â´Ù. Bridge´Â ³×Æ®¿öÅ©¿¡ ÇÑ ºÎºÐÀ̱⠶§¹®ÀÌ´Ù. 6. Question Ä¿³ÎÀÇ IP_FORWARD ¸¦ ÀçÄÄÆÄÀÏÇØ¾ß Çϴ°¡? Answer ÇÊ¿ä¾ø´Ù. Ä¿³Î¿¡¼­ Bridging ÄÚµå´Â ÆÐŶÀ» Àü¼ÛÀ» °ü¸®ÇÑ´Ù. IP_FORWARD ´Â °¢ ÀåÄ¡ÀÇ ¾ÆÀÌÇÇ ¾îµå·¹½ºÀÇ ¹Ù¿îµù µÇ´Â °ÔÀÌÆ®¿þÀÌÀÌ´Ù. 7. Question Æ÷Æ® 1 ,Æ÷Æ® 2 ÀÇ ÀÌ´õ³Ý ¾îµå·¹½º°¡ ¾î¶»°Ô °°Àº "brcfg" ÇÁ·Î±×·¥¿¡ ÀÇÇØ Á¿ìµÇ´Â°¡? µÎ°³ÀÇ Æ÷Æ®¸¦ ´Ù¸£°Ô ¼³Á¤ÇؾßÇϴ°¡? Answer ¾Æ´Ï´Ù. ¸ðµç Æ÷Æ®´Â Bridging Äڵ忡 ÀÇÇØ °°Àº ÀÌ´õ³Ý ¾îµå·¹½º·Î Ãë±ÞµÈ´Ù.±×·¯¹Ç·Î ÇÊ¿ä¾ø´Ù. 8. Question Ä¿³Î¼³Á¤½Ã Bridging ´ëÇÑ ¿É¼ÇÀÌ ³ªÅ¸³ªÁö ¾Ê´Â´Ù. ¾î¶»°Ô ÇØ¾ßÇϴ°¡? Answer Ä¿³Î ¼³Á¤Áß¿¡ ´ÙÀ½°ú Áú¹®ÀÌ ³ª¿À¸é 'Y' ·Î ´ë´äÇ϶ó. ``Prompt for development and/or incomplete code/drivers (CONFIG_EXPERIMENTAL)[Y/n/?]''. 9. Question ¸¹Àº Çãºê(4 ¶Ç´Â ´õ¸¹Àº)°¡ ´Ù¸¥ ½Ã¸®¾ó·Î ¿¬°áµÈ ÀÌ´õ³Ý¿¡¼­´Â °¢ ½Ã½ºÅÛ¿¡ ÀÌ´õ³Ý ½Ã°£ºÐ¹è¿¡ ¹®Á¦°¡ ÀÖ´Ù. Bridge ·Î ¼³Á¤µÈ ¼­ºê³Ý¿¡¼­´Â Çãºê·Î ¾ó¸¶Á¤µµ·Î ¿¬°áµÈ Á¤µµÀÇ È¿°ú°¡ Àִ°¡? Answer Bridge´Â 3/4/5 ÇãºêÁ¤µµ Ãʱ⼳Á¤ÀÌ µÇ¾îÀÖ´Ù. Bridge´Â Çãºê ¹æ½Ä°ú´Â ÆÐŶÀ» ó¸®ÇÏ´Â ¹æ¹ýÀÌ Æ²¸®´Ù. ±×·¸±â ¶§¹®¿¡ ³×Æ®¿öÅ©»óÀÇ ½Ã°£ºÐ¹è¹®Á¦¿¡ Àâ¾Æ¸ÔÈ÷Áö ¾Ê´Â´Ù. 10. Question 10Mb , 100Mb ÀÌ´õ³ÝÀåÄ¡¸¦ Bridge°¡ µ¿½Ã¿¡ Áö¿øÇÒ¼ö Àִ°¡? µ¥ÀÌÅÍ ¼ÒÅëÀÌ ºü¸¦¶§ ¼Óµµ ÀúÇÏ´Â ¾ø´Â°¡? Answer 10Mb , 100Mb ÀÌ´õ³ÝÀåÄ¡¸¦ µÎ°³ ´Ù Bridge ¿¡¼­ »ç¿ëÇÒ¼ö ÀÖ´Ù. 100Mb ¿Í °°Àº ºü¸¥ ³×Æ®¿öÅ© Ä«µå¿¡¼­´Â TCP ´Â ³²´Â ½Ã°£ÀÌ ÀÖ´Ù. 100Mb ÀÇ È£½ºÆ®¿¡¼­ 10Mb ÀÇ È£½ºÆ®·Î Àü¼ÛÇÒ¶§ÀÇ ¼Óµµ´Â 10Mb ¹Û¿¡´Â ³ª¿Ã¼ö°¡ ¾ø´Ù. µ¥ÀÌÅͼ۽ÅÀÇ ³²´Â ½Ã°£À» ¼ÓµµÀúÇϰ¡ ¾Æ´Ï´Ù.