bgp协议的四种报文是什么？ BGP协议的报文有哪些?各自有什么作用?
BGP\u7684\u4e3b\u8981\u529f\u80fd\u662f\u4ec0\u4e48\uff1f\u5b83\u7684\u62a5\u6587\u6709\u51e0\u79cd\uff1fBGP\u7528\u8fd9\u51e0\u79cd\u62a5\u6587\u5b9e\u73b0\u7684\u529f\u80fd\u8fc7\u7a0b\u6709\u54ea\u4e9b\uff1fBGP\u53eb\u8fb9\u754c\u7f51\u5173\u534f\u8bae\uff0c\u662f\u7528\u4e8eAS\u95f4\u7684\u4e00\u79cd\u8def\u7531\u534f\u8bae\u3002
ospf\u3001rip\u3001isis\u7b49\uff0c\u5747\u662f\u7528\u6765\u53d1\u73b0\u8def\u7531\u7684\u3002
\u800cBGP\u7684\u529f\u80fd\u4e3b\u8981\u662f\u7528\u6765\u7ba1\u7406\u8def\u7531\uff0c\u800c\u975e\u53d1\u73b0\u8def\u7531\uff0c\u7528\u4e8eisp\u4e4b\u95f4\u3002
\u62a5\u6587\u67094\u79cd\uff1aopen\uff0ckeepalive\uff0cupdate\uff0cnotification\u3002\u7528\u6b644\u4e2d\u62a5\u6587\uff0c\u67096\u79cd\u72b6\u6001\u673a\u3002
open\u7528\u6765\u5efa\u7acbbgp\u90bb\u5c45\u5173\u7cfb\uff0ckeepalive\u7528\u6765\u4fdd\u6301\u8fd9\u79cd\u8fde\u63a5\uff0cupdate\u7528\u6765\u53d1\u9001\u66f4\u65b0\u6216\u64a4\u9500\u7684\u8def\u7531\u6761\u76ee\uff0cnotification\u7528\u6765\u901a\u544a\u7f51\u7edc\u9519\u8bef\u3002
\u4e00\u4e2a\u5178\u578b\u7684\u8fc7\u7a0b\u4e3a\uff1aIdle(\u542f\u52a8\u6d88\u606f)->Connect(TCP\u8fde\u63a5\u6210\u529f\uff0c\u53d1OPEN)->OpenSent(\u6536\u5230OPEN\u6d88\u606f\uff0c\u534f\u5546\u6210\u529f)->OpenConfirm(\u6536\u5230KEEPALIVE\u6d88\u606f)->Established(TCP\u8fde\u63a5\u5173\u95ed\uff0c\u6709\u9519\u8bef\uff0c\u6216\u5904\u7406UPDATE\u6d88\u606f\u5931\u8d25\uff0c\u6216\u6536\u5230NOTIFICATION\u6d88\u606f)->Idle
Open ---includes holdtime and BGP router ID\uff0c\u5f53\u7136\u8fd8\u6709AS\u53f7\u3002
Keepalive ---\u6bcf\u969460S\u53d1\u9001\u4e00\u6b21\u3002hold time=180S
Update ---information for one path only (could be to multiple networks)
---Includes path attributes and networks
Notification
---when error is detected
---BGP connection is closed after sent
(2) 更新(Update)报文，用来发送某一路由的信息，以及列出要撤消的多条路由。
(3) 保活(Keepalive)报文，用来确认打开报文和周期性地证实邻站关系。
(4) 通知(Notificaton)报文，用来发送检测到的差错。
绛旓細BGP甯歌鍥涚鎶ユ枃锛歄PEN鎶ユ枃銆並EEPLIVE鎶ユ枃銆乁PDATE鎶ユ枃鍜孨OTIFICATION鎶ユ枃銆傦紙1锛塐PEN鎶ユ枃锛氬缓绔嬮偦灞呭叧绯汇傦紙2锛塊EEPLIVE鎶ユ枃锛氫繚鎸佹椿鍔ㄧ姸鎬侊紝鍛ㄦ湡鎬х‘璁ら偦灞呭叧绯伙紝瀵筄PEN鎶ユ枃鍥炲簲銆傦紙3锛塙PDATE鎶ユ枃锛氬彂閫佹柊鐨勮矾鐢变俊鎭傦紙4锛塏OTIFICATION鎶ユ枃锛氭姤鍛婃娴嬪埌鐨勯敊璇
绛旓細BGP鐨勫洓绉嶆姤鏂囷細open锛宬eepalive锛寀pdate锛宯otification銆傚叾涓璒PEN鏄疶CP杩炴帴寤虹珛鍚庡彂閫佺殑绗竴涓秷鎭紝鐢ㄦ潵寤虹珛BGP瀵圭瓑浣撲箣闂寸殑杩炴帴鍏崇郴骞惰繘琛屽弬鏁板崗鍟嗐侭GP浼氶氳繃鐩镐簰鍙戦並eepalive鐨勬暟鎹潵缁存寔閭诲眳鍏崇郴锛岄粯璁ゆ瘡60绉掑彂閫佷竴娆★紝淇濇寔鏃堕棿涓180绉掞紝鍗冲埌杈180绉掓病鏈夋敹鍒伴偦灞呯殑Keepalive锛屼究璁や负閭诲眳涓㈠け锛屽垯鏂紑涓庨偦...
绛旓細(4) 閫氱煡(Notificaton)鎶ユ枃锛岀敤鏉ュ彂閫佹娴嬪埌鐨勫樊閿欍
绛旓細鎶ユ枃鏈4绉嶏細open锛宬eepalive锛寀pdate锛宯otification銆傜敤姝4涓姤鏂囷紝鏈6绉嶇姸鎬佹満銆俹pen鐢ㄦ潵寤虹珛bgp閭诲眳鍏崇郴锛宬eepalive鐢ㄦ潵淇濇寔杩欑杩炴帴锛寀pdate鐢ㄦ潵鍙戦佹洿鏂版垨鎾ら攢鐨勮矾鐢辨潯鐩紝notification鐢ㄦ潵閫氬憡缃戠粶閿欒銆備竴涓吀鍨嬬殑杩囩▼涓猴細Idle(鍚姩娑堟伅)->Connect(TCP杩炴帴鎴愬姛锛屽彂OPEN)->OpenSent(鏀跺埌OPEN娑堟伅锛屽崗鍟嗘垚鍔...
绛旓細2銆乲eepalive鎶ユ枃 杩欎釜鎶ユ枃娌′粈涔堣鐨勶紝60s鍛ㄦ湡鍙戦侊紝涓婂浘澶у鍙互鐪嬬湅瀹冪殑鏍煎紡锛屽綋鐒朵綘浠篃鍙互鑷繁鎶撳寘鐪嬬湅銆3銆乽pdate 褰揃GP鐨刾eer浜掔浉鍙戦佷簡open鎶ユ枃锛岃屼笖鍗忓晢杩囦簡锛屼究寤虹珛杩炴帴锛岃繖涓窡IGP鐨勭壒鎬у緢鍍忥紝閭ｄ箞鐜板湪鎴戜滑鎯崇煡閬擄紝update鍒板簳鍙戦佷粈涔堝唴瀹癸紝鍏堢湅鐪嬫姤鏂囨牸寮忓惂锛
绛旓細Keepalive璁℃椂鍣ㄥ紑濮嬭鏃讹紝骞惰浆涓篛pen confirm鐘舵併 OPEN璇佸疄锛圤pen confirm锛夛細BGP绛夊緟Keepalive鎶ユ枃锛屽悓鏃跺浣嶄繚鎸佽鏃跺櫒銆傚鏋滄敹鍒颁簡Keepalive鎶ユ枃锛屽氨杞负Established鐘舵侊紝閭诲眳鍏崇郴鍗忓晢瀹屾垚銆傚鏋滅郴缁熸敹鍒颁竴鏉℃洿鏂版垨Keepalive娑堟伅锛屽畠灏嗛噸鏂板惎鍔ㄤ繚鎸佽鏃跺櫒锛涘鏋滄敹鍒癗otification娑堟伅锛...
绛旓細holdtime and BGP router ID锛屽綋鐒惰繕鏈堿S鍙枫侹eepalive ---姣忛殧60S鍙戦佷竴娆°俬old time=180S Update ---information for one path only (could be to multiple networks)---Includes path attributes and networks Notification ---when error is detected ---BGP connection is closed after sent ...
绛旓細BGP鍩轰簬TCP鍗忚锛屼互鍏堕珮鏁堟у拰鐏垫椿鎬ч椈鍚嶏紝閫氳繃AS锛圓utonomous System锛夌殑姒傚康锛岀‘淇濅笉鍚岀綉缁滈棿鐨勭ǔ瀹氶氫俊銆傛帴涓嬫潵锛岃鎴戜滑娣卞叆浜嗚ВBGP鐨勮繍浣滄満鍒讹紝浠庡熀纭姒傚康鍒伴珮绾х壒鎬э紝涓鍥捐В鏋勫畠鐨勭簿楂撱傞鍏堬紝BGP鐨勮繛鎺ュ缓绔嬭繃绋嬪崄鍒嗗叧閿傚绛変綋涔嬮棿閫氳繃鍙戦乀CP杩炴帴鐨keepalive鎶ユ枃鏉ョ淮鎶よ繛鎺ワ紝骞朵氦鎹㈣矾鐢变俊鎭侭GP鎶ユ枃...
绛旓細UPDATE鎶ユ枃鏄疊GP鍗忚鐨鏍稿績锛孊GP鍙戣█浜哄彲浠ヤ娇鐢║PDATE鎶ユ枃鎾ら攢瀹冧互鍓嶉氱煡杩囩殑璺敱锛屼篃鍙互瀹ｅ竷澧炲姞鏂扮殑璺敱锛 鎾ら攢璺敱鍙互涓娆℃ф挙閿璁稿鏉★紝浣嗘槸鏂板璺敱锛屾瘡涓猆PDATE鎶ユ枃鍙兘娣诲姞涓鏉° BGP鍙互寰堝鏄撳湴瑙ｅ喅璺濈鍚戦噺璺敱閫夋嫨绠楁硶涓殑鈥滃潖娑堟伅浼犳挱寰楁參鈥滆繖涓闂銆傚綋鏌愪釜璺敱鍣ㄦ垨鑰呴摼璺嚭鐜版晠闅滅殑鏃跺欙紝鐢变簬...
绛旓細BGP(Border Gateway Protocol)鍩烘湰鍔熻兘鍦ㄨ嚜娌荤郴缁熼棿鑷姩浜ゆ崲鏃犵幆璺殑璺敱淇℃伅锛岄氳繃浜ゆ崲甯︽湁鑷不鍖哄煙鍙凤紙AS锛夊簭鍒楀睘鎬х殑璺敱鍙揪淇℃伅锛屾潵鏋勯犺嚜娌诲尯鍩熺殑鎷撴墤鍥撅紝浠庤屾秷闄よ矾鐢辩幆璺苟瀹炴柦鐢ㄦ埛閰嶇疆鐨勭瓥鐣ャ BGP鐗圭偣 1銆佽窛绂荤煝閲鍗忚 2銆佷紶杈撳崗璁:TCP锛岀鍙ｅ彿锛179锛岋紙閲嶈锛 3銆佹敮鎸丆IDR锛堟棤绫诲埆鍩熼棿閫夎矾锛夛紙...
