ä»æ¥ã¯ BGP ãããã³ã«ã«ã€ããŠèŠãŠãããŸãã ããããªããªã®ãããããŠãªããããå¯äžã®ãããã³ã«ãšããŠäœ¿çšãããã®ãã«ã€ããŠã¯ãé·ãã¯è©±ããŸããã ãã®ä»¶ã«é¢ããŠã¯ãéåžžã«å€ãã®æ
å ±ããããŸããããšãã°ã
ã§ã¯ãBGP ãšã¯äœã§ãããã? BGP ã¯åçã«ãŒãã£ã³ã° ãããã³ã«ã§ãããå¯äžã® EGP (å€éšã²ãŒããŠã§ã€ ãããã³ã«) ãããã³ã«ã§ãã ãã®ãããã³ã«ã¯ãã€ã³ã¿ãŒãããäžã§ã«ãŒãã£ã³ã°ãæ§ç¯ããããã«äœ¿çšãããŸãã XNUMX ã€ã® BGP ã«ãŒã¿ãŒéã«è¿é£ãã©ã®ããã«æ§ç¯ãããããèŠãŠã¿ãŸãããã
Router1 ãš Router3 ã®éã®è¿åãèããŠã¿ãŸãããã 次ã®ã³ãã³ãã䜿çšããŠèšå®ããŠã¿ãŸãããã
router bgp 10
network 192.168.12.0
network 192.168.13.0
neighbor 192.168.13.3 remote-as 10
router bgp 10
network 192.168.13.0
network 192.168.24.0
neighbor 192.168.13.1 remote-as 10
åäžã®èªåŸã·ã¹ãã å ã®è¿é£ã¯ AS 10 ã§ããRouter1 ãªã©ã®ã«ãŒã¿ã«é¢ããæ å ±ãå ¥åããåŸããã®ã«ãŒã¿ã¯ Router3 ãšã®é£æ¥é¢ä¿ã確ç«ããããšããŸãã äœãèµ·ãããªãåæç¶æ ã ãšåŒã³ãŸãã ã¢ã€ãã«ã Router1 㧠bgp ãèšå®ããããšããã«ãTCP ããŒã 179 ã®ãªãã¹ã³ãéå§ããã次ã®ç¶æ ã«ãªããŸãã ãååããããŠãRouter3 ãšã®ã»ãã·ã§ã³ãéãããšãããšã次ã®ç¶æ ã«ãªããŸãã ã¢ã¯ãã£ã.
Router1 ãš Router3 ã®éã§ã»ãã·ã§ã³ã確ç«ãããåŸãOpen ã¡ãã»ãŒãžã亀æãããŸãã ãã®ã¡ãã»ãŒãžã Router1 ã«ãã£ãŠéä¿¡ããããšããã®ç¶æ ãåŒã³åºãããŸãã éä¿¡æžã¿ãéãã Router3 ãã Open ã¡ãã»ãŒãžãåä¿¡ãããšãç¶æ ã«ãªããŸãã éã 確èªã Open ã¡ãã»ãŒãžã詳ããèŠãŠã¿ãŸãããã
ãã®ã¡ãã»ãŒãžã¯ãã«ãŒã¿ãŒã䜿çšãã BGP ãããã³ã«èªäœã«é¢ããæ
å ±ãäŒããŸãã Open ã¡ãã»ãŒãžã亀æããããšã«ãããRouter1 ãš Router3 ã¯äºãã®èšå®ã«é¢ããæ
å ±ãéä¿¡ããŸãã 次ã®ãã©ã¡ãŒã¿ãæž¡ãããŸãã
- : ããã«ã¯ãã«ãŒã¿ãŒã䜿çšããŠãã BGP ããŒãžã§ã³ãå«ãŸããŸãã BGP ã®çŸåšã®ããŒãžã§ã³ã¯ãRFC 4 ã§èª¬æãããŠããããŒãžã§ã³ 4271 ã§ããXNUMX ã€ã® BGP ã«ãŒã¿ãŒã¯äºææ§ã®ããããŒãžã§ã³ãããŽã·ãšãŒãããããšããŸããäžäžèŽãããå ŽåãBGP ã»ãã·ã§ã³ã¯ååšããŸããã
- ç§ã®AS: ããã«ã¯ãBGP ã«ãŒã¿ãŒã® AS çªå·ãå«ãŸããŸããã«ãŒã¿ãŒã¯ AS çªå·ã«åæããå¿ èŠããããiBGP ãŸã㯠eBGP ãå®è¡ãããã©ãããå®çŸ©ãããŸãã
- ããŒã«ãã¿ã€ã : BGP ãä¿ææéäžã«çžæåŽããããŒãã¢ã©ã€ããŸãã¯æŽæ°ã¡ãã»ãŒãžãåä¿¡ããªãå ŽåãçžæåŽããããããã§ãããšå®£èšãããBGP ã»ãã·ã§ã³ãåæãããŸãã ããã©ã«ãã§ã¯ãCisco IOS ã«ãŒã¿ã®ä¿ææé㯠180 ç§ã«èšå®ãããŠãããããŒãã¢ã©ã€ã ã¡ãã»ãŒãžã¯ 60 ç§ããšã«éä¿¡ãããŸãã äž¡æ¹ã®ã«ãŒã¿ãŒãããŒã«ã ã¿ã€ã ã«ã€ããŠåæããå¿ èŠããããŸããããããªããšãBGP ã»ãã·ã§ã³ã確ç«ãããŸããã
- BGP èå¥å: ããã¯ãOSPF ãšåãããã«éžæãããããŒã«ã« BGP ã«ãŒã¿ãŒ ID ã§ãã
- bgp router-id ã³ãã³ãã䜿çšããŠæåã§èšå®ããã«ãŒã¿ãŒ ID ã䜿çšããŸãã
- ã«ãŒããã㯠ã€ã³ã¿ãŒãã§ã€ã¹ã§æã倧ãã IP ã¢ãã¬ã¹ã䜿çšããŸãã
- ç©çã€ã³ã¿ãŒãã§ã€ã¹äžã§æã倧ãã IP ã¢ãã¬ã¹ã䜿çšããŸãã
- ãªãã·ã§ã³ã®ãã©ã¡ãŒã¿: ããã«ã¯ãBGP ã«ãŒã¿ãŒã®ãªãã·ã§ã³æ©èœãããã€ããããŸãã ãã®ãã£ãŒã«ãã¯ãæ°ããããŒãžã§ã³ãäœæããã«æ°ããæ©èœã BGP ã«è¿œå ã§ããããã«è¿œå ãããŸãããããã§èŠã€ããå¯èœæ§ããããã®ã¯æ¬¡ã®ãšããã§ãã
- MP-BGP (ãã«ããããã³ã« BGP) ã®ãµããŒãã
- ã«ãŒããªãã¬ãã·ã¥ã®ãµããŒãã
- 4 ãªã¯ããã AS çªå·ã®ãµããŒãã
è¿é£ã確ç«ããã«ã¯ã次ã®æ¡ä»¶ãæºããå¿ èŠããããŸãã
- ããŒãžã§ã³ãã³ããŒã çŸåšã®ããŒãžã§ã³ã¯4ã§ãã
- AS çªå·ã¯èšå®ãããã®ãšäžèŽããå¿ èŠããããŸã é£äºº 192.168.13.3 ãªã¢ãŒããšã㊠10.
- ã«ãŒã¿ãŒ ID ã¯é£æ¥ã«ãŒã¿ãŒãšã¯ç°ãªãå¿ èŠããããŸãã
ããããã®ãã©ã¡ãŒã¿ããããã®æ¡ä»¶ãæºãããªãå Žåãã«ãŒã¿ãŒã¯ éç¥ã§ãã ãšã©ãŒã瀺ãã¡ãã»ãŒãžã Open ã¡ãã»ãŒãžã®éåä¿¡åŸãè¿é£é¢ä¿ãç¶æ ã«ãªããŸãã èšç«ã ãã®åŸãã«ãŒã¿ãŒã¯ã«ãŒãã«é¢ããæ å ±ã亀æããããã次ã®ããã«è¡ãããšãã§ããŸãã ã¢ãããã€ã ã¡ãã»ãŒãžã ãã㯠Router1 ãã Router3 ã«éä¿¡ããã Update ã¡ãã»ãŒãžã§ãã
ããã§ã¯ãã¡ããªãã¯ã«äŒŒã Router1 ããã³ Path å±æ§ã«ãã£ãŠã¬ããŒãããããããã¯ãŒã¯ã確èªã§ããŸãã Path å±æ§ã«ã€ããŠè©³ãã説æããŸãã ããŒãã¢ã©ã€ã ã¡ãã»ãŒãžã¯ TCP ã»ãã·ã§ã³å ã§ãéä¿¡ãããŸãã ããã©ã«ãã§ã¯ã60 ç§ããšã«éä¿¡ãããŸãã ããã¯ããŒãã¢ã©ã€ãã¿ã€ããŒã§ãã ããŒãã¢ã©ã€ã ã¡ãã»ãŒãžãããŒã«ã ã¿ã€ããŒäžã«åä¿¡ãããªãå Žåãããã¯ãã€ããŒãšã®éä¿¡ã倱ãããããšãæå³ããŸãã ããã©ã«ãã§ã¯ã180 ç§ã«çžåœããŸãã
䟿å©ãªæšè:
ã«ãŒã¿ãŒãçžäºã«æ å ±ãéä¿¡ããæ¹æ³ãç解ã§ããããã§ãã次ã«ãBGP ãããã³ã«ã®ããžãã¯ãç解ããŠã¿ãŸãããã
BGP ããŒãã«ã«ã«ãŒããåºåããã«ã¯ãIGP ãããã³ã«ãšåæ§ã« network ã³ãã³ãã䜿çšããŸãããåäœããžãã¯ãç°ãªããŸãã IGP ã®å Žåãnetwork ã³ãã³ãã§ã«ãŒããæå®ããåŸãIGP ã¯ã©ã®ã€ã³ã¿ãŒãã§ã€ã¹ããã®ãµããããã«å±ããŠãããã調ã¹ãŠããŒãã«ã«å«ããŸãã次ã«ãBGP ã® network ã³ãã³ãã¯ã«ãŒãã£ã³ã° ããŒãã«ã調ã¹ãŠã æ£ç¢º network ã³ãã³ãã®ã«ãŒããšäžèŽããŸãã ãã®ãããªã«ãŒããèŠã€ãã£ãå Žåããããã®ã«ãŒã㯠BGP ããŒãã«ã«è¡šç€ºãããŸãã
ã«ãŒã¿ãŒã®çŸåšã® IP ã«ãŒãã£ã³ã° ããŒãã«ã§ãnetwork ã³ãã³ãã®ãã©ã¡ãŒã¿ãŒãšæ£ç¢ºã«äžèŽããã«ãŒããæ¢ããŸãã IP ã«ãŒããååšããå Žåã¯ãåçã® NLRI ãããŒã«ã« BGP ããŒãã«ã«è¿œå ããŸãã
次ã«ãæ®ããã¹ãŠã® BGP ãäžããŠãXNUMX ã€ã® AS å ã§ã«ãŒããã©ã®ããã«éžæãããããèŠãŠã¿ãŸãããã BGP ã«ãŒã¿ãŒã¯è¿é£ããã«ãŒããåä¿¡ãããšãæé©ãªã«ãŒãã®éžæãéå§ããŸãã ããã§ã¯ãå éšãšå€éšã®ã©ã®ãããªçš®é¡ã®é£æ¥é¢ä¿ãååšããå¯èœæ§ãããããç解ããå¿ èŠããããŸãã ã«ãŒã¿ã¯èšå®ã«ãã£ãŠãèšå®ããããã€ããŒãå éšãå€éšããèªèããŸãã? ããŒã ã®å Žå:
neighbor 192.168.13.3 remote-as 10
Remote-as ãã©ã¡ãŒã¿ã¯ãrouter bgp 10 ã³ãã³ãã§ã«ãŒã¿èªäœã«èšå®ããã AS ãæå®ããŸããå éš AS ããã®ã«ãŒãã¯å éšãšã¿ãªãããå€éš AS ããã®ã«ãŒãã¯å€éšãšã¿ãªãããŸãã ãããŠãããããã«å¯ŸããŠãåä¿¡ãšéä¿¡ã®ç°ãªãããžãã¯ãæ©èœããŸãã 次ã®ããããžãèããŠã¿ãŸãããã
åã«ãŒã¿ãŒã«ã¯ãip: xxxx 255.255.255.0 - x ã¯ã«ãŒã¿ãŒçªå·ã§æ§æãããã«ãŒããã㯠ã€ã³ã¿ãŒãã§ã€ã¹ããããŸãã Router9 ã«ã¯ãã¢ãã¬ã¹ 9.9.9.9 255.255.255.0 ã®ã«ãŒããã㯠ã€ã³ã¿ãŒãã§ã€ã¹ããããŸãã BGP çµç±ã§ã¢ããŠã³ã¹ããã©ã®ããã«åºããããèŠãŠãããŸãã ãã®ã«ãŒã㯠Router8 ãš Router12 ã«éä¿¡ãããŸãã ãã®ã«ãŒã㯠Router8 ãã Router6 ã«é²ã¿ãŸãããRouter5 ãžã¯ã«ãŒãã£ã³ã° ããŒãã«ã«å«ãŸããŸããã ãŸããRouter12 ã§ã¯ãã®ã«ãŒããããŒãã«ã«è¡šç€ºãããŸãããRouter11 ã§ã¯ããŒãã«ã«ã衚瀺ãããŸããã ãããç解ããŠã¿ãŸãããã Router9 ãã©ã®ãããªããŒã¿ãšãã©ã¡ãŒã¿ãè¿é£ã«éä¿¡ãããã®ã«ãŒããå ±åããããèããŠã¿ãŸãããã 以äžã®ãã±ãã㯠Router9 ãã Router8 ã«éä¿¡ãããŸãã
ã«ãŒãæ
å ±ã¯ Path å±æ§ã§æ§æãããŸãã
ãã¹å±æ§ã¯ 4 ã€ã®ã«ããŽãªã«åé¡ãããŸãã
- ããç¥ãããŠããå¿ é - BGP ãå®è¡ããŠãããã¹ãŠã®ã«ãŒã¿ãŒã¯ããããã®å±æ§ãèªèããå¿ èŠããããŸãã ãã¹ãŠã®ã¢ããããŒãã«ååšããå¿ èŠããããŸãã
- æåãªè£éæš© - BGP ãå®è¡ããŠãããã¹ãŠã®ã«ãŒã¿ãŒã¯ããããã®å±æ§ãèªèããå¿ èŠããããŸãã ãããã¯ã¢ããããŒãã«å«ãŸããå ŽåããããŸãããå¿ é ã§ã¯ãããŸããã
- ãªãã·ã§ã³ã®æšç§»ç - ãã¹ãŠã® BGP å®è£ ã§èªèãããããã§ã¯ãããŸããã ã«ãŒã¿ãå±æ§ãèªèããªãå ŽåãæŽæ°ãéšåçãªãã®ãšããŠããŒã¯ããèªèã§ããªãå±æ§ãä¿åããŠé£æ¥ã«ãŒã¿ã«è»¢éããŸãã
- ãªãã·ã§ã³ã®éæšç§»ç - ãã¹ãŠã® BGP å®è£ ã§èªèãããããã§ã¯ãããŸããã ã«ãŒã¿ãå±æ§ãèªèããªãå Žåããã®å±æ§ã¯ç¡èŠãããè¿é£ã«ãŒã¿ã«æž¡ããããšãã«ç Žæ£ãããŸãã
BGP å±æ§ã®äŸ:
- ããç¥ãããŠããå¿
é :
- èªåŸã·ã¹ãã ãã¹
- ãã¯ã¹ãããã
- Origin
- æåãªè£éæš©:
- å°åã®å¥œã¿
- ååéåäœ
- ãªãã·ã§ã³ã®æšç§»ç:
- ã¢ã°ãªã²ãŒã¿ãŒ
- ã³ãã¥ããã£
- ãªãã·ã§ã³ã®éæšç§»ç:
- å€åºå£åŒå¥åš (MED)
- çºä¿¡è ID
- ã¯ã©ã¹ã¿ãŒãªã¹ã
ãã®å Žåãä»ã®ãšãããOriginãNext-hopãAS Path ã«æ³šç®ããŸãã ãã®ã«ãŒã㯠Router8 ãš Router9 ã®éãã€ãŸã XNUMX ã€ã® AS å ã§éä¿¡ããããããå éšãšã¿ãªãããOrigin ã«æ³šç®ããŸãã
Origin å±æ§ - æŽæ°å ã®ã«ãŒããã©ã®ããã«ååŸããããã瀺ããŸãã å¯èœãªå±æ§å€:
- 0 - IGP: å ã®èªåŸã·ã¹ãã å ã§åä¿¡ããã NLRIã
- 1 - EGP: NLRI 㯠Exterior Gateway Protocol (EGP) ã䜿çšããŠåŠç¿ãããŸãã BGP ã®å身ãæªäœ¿çš
- 2 - äžå®å š: NLRI ã¯ä»ã®æ¹æ³ã§åŠç¿ãããŸãã
ãã®å Žåããã±ããããåããããã«ããã㯠0 ã«çããã§ãããã®ã«ãŒãã Router12 ã«éä¿¡ããããšããã®ã³ãŒãã®ã³ãŒã㯠1 ã«ãªããŸãã
次ã«ããã¯ã¹ããããã ãã¯ã¹ããããå±æ§
- ããã¯ãå®å ãããã¯ãŒã¯ãžã®ãã¹ãééãã eBGP ã«ãŒã¿ãŒã® IP ã¢ãã¬ã¹ã§ãã
- ãã¬ãã£ãã¯ã¹ãå¥ã® AS ã«éä¿¡ããããšå±æ§ãå€ãããŸãã
iBGP ã®å Žåãã€ãŸã 192.168.89.9 ã€ã® AS å ã§ããã¯ã¹ããããã¯ããã®ã«ãŒãã«ã€ããŠåŠç¿ãŸãã¯éç¥ããããã®ã«ãã£ãŠç€ºãããŸãã ãã®äŸã§ã¯ã8 ã«ãªããŸãã ãã ãããã®ã«ãŒãã Router6 ãã Router8 ã«éä¿¡ããããšãRouter192.168.68.8 ã¯ãããå€æŽããç¬èªã®ã«ãŒãã«çœ®ãæããŸãã ãã¯ã¹ãããã㯠XNUMX ã«ãªããŸãã ããã«ããã次㮠XNUMX ã€ã®ã«ãŒã«ãå°ãåºãããŸãã
- ã«ãŒã¿ãŒãã«ãŒããå éšãã€ããŒã«è»¢éããå Žåããã¯ã¹ãããã ãã©ã¡ãŒã¿ãŒã¯å€æŽãããŸããã
- ã«ãŒã¿ãŒãå€éšãã€ããŒã«ã«ãŒããéä¿¡ããå Žåããã¯ã¹ããããããã®ã«ãŒã¿ãŒã®éä¿¡å ã€ã³ã¿ãŒãã§ã€ã¹ã® IP ã«å€æŽããŸãã
ããã«ãããæåã®åé¡ãRouter5 ãš Router11 ã®ã«ãŒãã£ã³ã° ããŒãã«ã«ã«ãŒããååšããªãçç±ãããããŸãã 詳ããèŠãŠã¿ãŸãããã ãããã£ãŠãRouter6 ã¯ã«ãŒã 9.9.9.0/24 ã«é¢ããæ å ±ãåä¿¡ãããããã«ãŒãã£ã³ã° ããŒãã«ã«æ£åžžã«è¿œå ããŸããã
Router6#show ip route bgp
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
a - application route
+ - replicated route, % - next hop override, p - overrides from PfR
Gateway of last resort is not set
9.0.0.0/24 is subnetted, 1 subnets
B 9.9.9.0 [20/0] via 192.168.68.8, 00:38:25<source>
ТепеÑÑ Router6 пеÑеЎал ЌаÑÑÑÑÑ Router5 О пеÑÐ²ÐŸÐŒÑ Ð¿ÑÐ°Ð²ÐžÐ»Ñ Next-hop Ме ОзЌеМОл. ТП еÑÑÑ, Router5 ЎПлжеМ ЎПбавОÑÑ <b>9.9.9.0 [20/0] via 192.168.68.8</b> , МП Ñ ÐœÐµÐ³ÐŸ ÐœÐµÑ ÐŒÐ°ÑÑÑÑÑа ЎП 192.168.68.8 О пПÑÑÐŸÐŒÑ ÐŽÐ°ÐœÐœÑй ЌаÑÑÑÑÑ ÐŽÐŸÐ±Ð°Ð²Ð»ÐµÐœ Ме бÑЎеÑ, Ñ
ПÑÑ ÐžÐœÑПÑЌаÑÐžÑ ÐŸ ЎаММПЌ ЌаÑÑÑÑÑе бÑÐŽÐµÑ Ñ
ÑаМОÑÑÑÑ Ð² ÑаблОÑе BGP:
<source><b>Router5#show ip bgp
BGP table version is 1, local router ID is 5.5.5.5
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
* i 9.9.9.0/24 192.168.68.8 0 100 0 45 i</b>
åãç¶æ³ã Router11 ãš Router12 ã®éã§ãçºçããŸãã ãã®ç¶æ³ãåé¿ããã«ã¯ãå éšãã€ããŒã«ã«ãŒããæž¡ããšãã«ããã® IP ã¢ãã¬ã¹ããã¯ã¹ãããããšããŠçœ®ãæããããã« Router6 ãŸã㯠Router12 ãèšå®ããå¿ èŠããããŸãã ããã¯æ¬¡ã®ã³ãã³ãã䜿çšããŠè¡ãããŸãã
neighbor 192.168.56.5 next-hop-self
ãã®ã³ãã³ãã®åŸãRouter6 㯠Update ã¡ãã»ãŒãžãéä¿¡ããŸãããã®ã¡ãã»ãŒãžã§ã¯ãã€ã³ã¿ãŒãã§ã€ã¹ Gi0/0 Router6 ã® IP ãã«ãŒãã®ãã¯ã¹ãããããšã㊠192.168.56.6 ã«æå®ããããã®åŸããã®ã«ãŒãã¯ãã§ã«ã«ãŒãã£ã³ã° ããŒãã«ã«å«ãŸããŠããŸãã
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neighbor 192.168.57.7 route-reflector-client
Route-Reflector ã¯ãã«ãŒããå éšãã€ããŒã«æž¡ããšãã® BGP ã®åäœãå€æŽããŸãã å éšãã€ããŒã次ã®ããã«æå®ãããŠããå Žå ã«ãŒããªãã¬ã¯ã¿ãŒã¯ã©ã€ã¢ã³ãããã®åŸãå éšã«ãŒãããããã®ã¯ã©ã€ã¢ã³ãã«ã¢ããã¿ã€ãºãããŸãã
Router7 ã«ã«ãŒãã衚瀺ãããŸããã§ããã? ãã¯ã¹ãããããå¿ããªãã§ãã ããã ãããã®æäœã®åŸãã«ãŒã㯠Router7 ã«ãè¡ãã¯ãã§ãããããã¯èµ·ãããŸããã ããã«ããã次ã®ãããªå¥ã®ã«ãŒã«ãåŸãããŸãã
ãã¯ã¹ãããã ã«ãŒã«ã¯å€éšã«ãŒãã«å¯ŸããŠã®ã¿æ©èœããŸãã å éšã«ãŒãã®å Žåããã¯ã¹ããããå±æ§ã¯çœ®ãæããããŸããã
ãããŠãAS å ã®ãã¹ãŠã®ã«ãŒããã«ãŒã¿ãŒã«éç¥ããããã«ãã¹ã¿ãã£ã㯠ã«ãŒãã£ã³ã°ãŸã㯠IGP ãããã³ã«ã䜿çšããŠç°å¢ãäœæããå¿ èŠãããç¶æ³ãçºçããŸãã Router6 ãš Router7 ã«ã¹ã¿ãã£ã㯠ã«ãŒããç»é²ããŸãããããã®åŸãã«ãŒã¿ãŒ ããŒãã«ã«ç®çã®ã«ãŒããååŸããŸãã AS 678 ã§ã¯ãå°ãç°ãªãæ¹æ³ã§è¡ããŸããRouter192.168.112.0 ã« 24/10 ã®ã¹ã¿ãã£ã㯠ã«ãŒããç»é²ããRouter192.168.110.0 ã« 24/12 ã®ã¹ã¿ãã£ã㯠ã«ãŒããç»é²ããŸãã 次ã«ãRouter10 ãš Router12 ã®éã®è¿é£é¢ä¿ã確ç«ããŸãã ãŸããRouter12 ã®ãã¯ã¹ããããã Router10 ã«éä¿¡ããããã«èšå®ããŸãã
neighbor 192.168.110.10 next-hop-self
ãã®çµæãRouter10 ã¯ã«ãŒã 9.9.9.0/24 ãåä¿¡ããRouter7 ãš Router12 ã®äž¡æ¹ããåä¿¡ããããšã«ãªããŸãã Router10 ãã©ã®ãããªéžæãããããèŠãŠã¿ãŸãããã
Router10#show ip bgp
BGP table version is 3, local router ID is 6.6.6.6
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*>i 9.9.9.0/24 192.168.112.12 0 100 0 45 i
192.168.107.7 0 123 45 i
ã芧ã®ãšããã192.168.112.12 ã€ã®ã«ãŒããšç¢å° (>) ã¯ãXNUMX çµç±ã®ã«ãŒããéžæãããŠããããšãæå³ããŸãã
ã«ãŒãéžæããã»ã¹ãã©ã®ããã«æ©èœããããèŠãŠã¿ãŸãããã
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- 次ã«éã¿ãã©ã¡ãŒã¿ãæ¥ãŸãã ãã®ãã©ã¡ãŒã¿ã¯ãã¹å±æ§ (PA) ã§ã¯ãªããããBGP ã¡ãã»ãŒãžã§ã¯éä¿¡ãããŸããã ããã¯åã«ãŒã¿ãŒäžã§ããŒã«ã«ã«æ§æãããã«ãŒã¿ãŒèªäœã§ã®ã«ãŒãéžæãæäœããããã«ã®ã¿äœ¿çšãããŸãã äŸãèŠãŠã¿ãŸãããã ããäžã§ã¯ãRouter10 ã Router9.9.9.0 (24) çµç±ã§ 12/192.168.112.12 ãžã®ã«ãŒããéžæããŠããããšãããããŸãã Wiigh ãã©ã¡ãŒã¿ãå€æŽããã«ã¯ãroute-map ã䜿çšããŠç¹å®ã®ã«ãŒããèšå®ãããã次ã®ã³ãã³ãã䜿çšããŠãã®ãã€ããŒã«éã¿ãå²ãåœãŠãŸãã
neighbor 192.168.107.7 weight 200
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Router10#show bgp *Mar 2 11:58:13.956: %SYS-5-CONFIG_I: Configured from console by console BGP table version is 2, local router ID is 6.6.6.6 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 9.9.9.0/24 192.168.107.7 200 123 45 i * i 192.168.112.12 0 100 0 45 i
ã芧ã®ãšãããRouter7 ãçµç±ããã«ãŒããéžæãããŠããŸãããããã¯ä»ã®ã«ãŒã¿ãŒã«ã¯åœ±é¿ããŸããã
- 5 çªç®ã®äœçœ®ã«ã¯ Local Preference ããããŸãã ãã®ãã©ã¡ãŒã¿ã¯ããç¥ãããä»»æã®å±æ§ã§ããããã®ååšã¯ãªãã·ã§ã³ã§ããããšãæå³ããŸãã ãã®ãã©ã¡ãŒã¿ã¯ 5 ã€ã® AS å
ã§ã®ã¿æå¹ã§ãããå
éšãã€ããŒã®ãã¹ã®éžæã«ã®ã¿åœ±é¿ããŸãã ãã®ãããå
éšãã€ããŒå®ãŠã®æŽæ°ã¡ãã»ãŒãžã§ã®ã¿éä¿¡ãããŸãã ããã¯ãå€éšãã€ããŒã®æŽæ°ã¡ãã»ãŒãžã«ã¯ååšããŸããã ãããã£ãŠãããã¯åšç¥ã®è£éãšããŠåé¡ãããŸããã Router9.9.9.0ã«é©çšããŠã¿ãŸãã Router24 ã«ã¯ã6/7 çšã® XNUMX ã€ã®ã«ãŒããå¿
èŠã§ããXNUMX ã€ã¯ RouterXNUMX ãçµç±ããXNUMX ã€ç®ã¯ RouterXNUMX ãçµç±ããŸãã
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Router5#show bgp BGP table version is 2, local router ID is 5.5.5.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.56.6 0 100 0 45 i
ããããRouter6 ãçµç±ããã«ãŒãã 7 ã€ããããšãããããŸãã Router7ãçµç±ããã«ãŒãã¯ã©ãã§ãã? ããããããRouterXNUMXã«ãããããªãã®ã§ããããïŒ èŠãŠã¿ããïŒ
Router#show bgp BGP table version is 10, local router ID is 7.7.7.7 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.56.6 0 100 0 45 i 192.168.107.10 0 678 45 i
äžæè°ãªããšã«ããã¹ãŠãããŸããã£ãŠããããã§ãã Router5 ã«éä¿¡ãããªãã®ã¯ãªãã§ãã? åé¡ã¯ãBGP ã«ã¯æ¬¡ã®ã«ãŒã«ããããšããããšã§ãã
ã«ãŒã¿ãŒã¯ã䜿çšããã«ãŒãã®ã¿ãéä¿¡ããŸãã
Router7 㯠Router5 ãçµç±ããçµè·¯ã䜿çšãããããRouter10 ãçµç±ããçµè·¯ã¯éä¿¡ãããŸããã ããŒã«ã«èšå®ã«æ»ããŸãããã Router7 ã§ããŒã«ã«èšå®ãèšå®ããRouter5 ãããã«ã©ã®ããã«åå¿ããããèŠãŠã¿ãŸãããã
route-map BGP permit 10 match ip address 10 set local-preference 250 access-list 10 permit any router bgp 123 neighbor 192.168.107.10 route-map BGP in</b>
ããã§ããã¹ãŠã®ã«ãŒããå«ãã«ãŒãããããäœæããåä¿¡æã« Local Preference ãã©ã¡ãŒã¿ã 7 ã«å€æŽããããã« Router250 ã«æ瀺ããŸãããããã©ã«ã㯠100 ã§ãã Router5 ã§äœãèµ·ãã£ãã®ãèŠãŠã¿ãŸãããã
Router5#show bgp BGP table version is 8, local router ID is 5.5.5.5 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *>i 9.9.9.0/24 192.168.57.7 0 250 0 678 45 i
ããã§ãããããã«ãRouter5 㯠Router7 ãçµç±ããã«ãŒããåªå ããŸãã åãåçã Router6 ã«ã衚瀺ãããŸãããRouter8 ãçµç±ããã«ãŒããéžæããæ¹ãæçã§ãã ãŸãããã®ãã©ã¡ãŒã¿ãå€æŽããã«ã¯ãå€æŽãæå¹ã«ããããã«è¿é£ãåèµ·åããå¿ èŠãããããšãä»ãå ããŸãã èªã
ãã㧠ã ããŒã«ã«èšå®ãæŽçããŸããã 次ã®ãã©ã¡ãŒã¿ã«é²ã¿ãŸãããã - ãã¯ã¹ãããã ãã©ã¡ãŒã¿ 0.0.0.0 ãæã€ã«ãŒããã€ãŸãããŒã«ã« ã«ãŒããŸãã¯éçŽã«ãŒããåªå
ããŸãã ãããã®ã«ãŒãã«ã¯ã次㮠network ã³ãã³ããå
¥åãããšãæå€§å€ (32678) ã«çãã Weight ãã©ã¡ãŒã¿ãèªåçã«å²ãåœãŠãããŸãã
Router#show bgp BGP table version is 2, local router ID is 9.9.9.9 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path *> 9.9.9.0/24 0.0.0.0 0 32768 i
- AS ãééããæçãã¹ã æãçã AS_Path ãã©ã¡ãŒã¿ãéžæãããŸãã ã«ãŒããééãã AS ã®æ°ãå°ãªãã»ã©ãããåªããŠããŸãã Router9.9.9.0 äžã® 24/10 ãžã®ã«ãŒããèããŠã¿ãŸãããã
Router10#show bgp BGP table version is 2, local router ID is 6.6.6.6 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal, r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter, x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? - incomplete RPKI validation codes: V valid, I invalid, N Not found Network Next Hop Metric LocPrf Weight Path * 9.9.9.0/24 192.168.107.7 0 123 45 i *>i 192.168.112.12 0 100 0 45 i
ã芧ã®ãšãããRouter10 㯠192.168.112.12 çµç±ã®ã«ãŒããéžæããŸãããããã¯ããã®ã«ãŒãã® AS_Path ãã©ã¡ãŒã¿ã« 45 ã®ã¿ãå«ãŸããŠãããå¥ã®ã±ãŒã¹ã§ã¯ 123 ãš 45 ãå«ãŸããŠããããã§ããçŽæçã«æããã§ãã
- 次ã®ãã©ã¡ãŒã¿ã¯åç¹ã§ãã IGP (BGP ã䜿çšããŠååŸãããã«ãŒã) 㯠EGP (BGP ã®åä»»è ã䜿çšããŠååŸããããçŸåšã¯äœ¿çšãããŠããªã) ãããåªããŠãããEGP ã¯äžå®å šãããåªããŠããŸãã? (åé åžãªã©ãä»ã®æ¹æ³ã§ååŸãããŸã)ã
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