CCIE实验备考之BGP(2) 
版权声明：原创作品，谢绝转载！否则将追究法律责任。 |
汇总设置：
1.bgp是无类路由协议，支持VLSM，但会要求最长匹配，一般它默认启动自动汇总的，但我们要求关闭自动汇总，不然就会像EIGRP那样出现问题，命令： no auto-summary 2.手工汇总方法1： 1） network 汇总路由 mask 汇总后的子网掩码 2） ip route 汇总路由 汇总后的子网掩码 null0 network命令本身不能汇总路由，它只是把经过igp汇总后的路由发布出去，然后还要手工指定一条静态汇总路由，指向null接口，不仅发布汇总路由，也会把具体的路由发布出去，如果不想把具体路由发布出去，需要路由过滤。 3.手工汇总方法2： aggregate-address ip地址 子网掩码 参数 参数： summary-only：只发送汇总的路由，具体的路由不会发布出去 r2#show ip route Codes: 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, 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 Gateway of last resort is not set
B 199.1.3.0/24 [20/0] via 192.1.1.1, 00:00:09 //要汇总的条目
B 199.1.2.0/24 [20/0] via 192.1.1.1, 00:00:09 B 199.1.1.0/24 [20/0] via 192.1.1.1, 00:00:09 C 193.1.1.0/24 is directly connected, Ethernet0 C 192.1.1.0/24 is directly connected, Serial1 B 199.1.4.0/24 [20/0] via 192.1.1.1, 00:00:09 B 199.1.0.0/22 [20/0] via 192.1.1.1, 00:00:09 //这是汇总之后的路由 加入参数后 r2#show ip route Codes: 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, 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 Gateway of last resort is not set
C 193.1.1.0/24 is directly connected, Ethernet0
C 192.1.1.0/24 is directly connected, Serial1 B 199.1.0.0/22 [20/0] via 192.1.1.1, 00:00:09 r1#show ip bgp
BGP table version is 18, local router ID is 192.168.194.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path
*> 192.1.1.0 0.0.0.0 0 32768 ? *> 193.1.1.0 0.0.0.0 2 32768 ? s> 199.1.2.0 0.0.0.0 0 32768 ? //抑制住的路由 *> 192.168.192.0/21 0.0.0.0 32768 i s> 199.1.1.0 0.0.0.0 0 32768 ? s> 199.1.3.0 0.0.0.0 0 32768 ? s> 199.1.4.0 0.0.0.0 2 32768 ?  Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*>i192.168.192.0/21 10.1.1.9 100 0 {50,200} i *> 200.200.200.0 0.0.0.0 0 32768 i 修改加参数： router bgp 100 aggregate-address 192.168.192.0 255.255.248.0 as-set summary-only advertise-map cisco ...... ! ip as-path access-list 1 permit ^200$ ! route-map cisco permit 10 match as-path 1 ! r4#show ip bgp
BGP table version is 17, local router ID is 200.200.200.201 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path
*>i192.168.192.0/21 10.1.1.9 100 0 200 i *> 200.200.200.0 0.0.0.0 0 32768 i suppress-map:抑制汇总路由指定的条目
router bgp 100 aggregate-address 192.168.192.0 255.255.248.0 suppress-map supmap ! access-list 1 permit 192.168.195.0 access-list 1 permit 192.168.197.0 route-map supmap permit 10 match ip address 1 ! r3#show ip bgp BGP table version is 10, local router ID is 3.3.3.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path
*> 192.168.192.0 10.1.1.1 0 0 50 i *> 192.168.192.0/21 0.0.0.0 32768 i *> 192.168.193.0 10.1.1.1 0 0 50 i *> 192.168.194.0 10.1.1.1 0 0 50 i *> 192.168.196.0 10.1.1.5 0 0 200 i s> 192.168.197.0 10.1.1.5 0 0 200 i *> 192.168.198.0 10.1.1.5 0 0 200 i *>i200.200.200.0 10.1.1.10 0 100 0 i ---------------------------------------------------------------------------------- 路由策略： 1.distribute-list过滤列表 命令： neighbor 邻居 distribute-list 访控号 [in | out] router bgp 100 neighbor 10.1.1.1 remote-as 50 neighbor 10.1.1.5 remote-as 200 neighbor 10.1.1.10 remote-as 100 neighbor 10.1.1.10 next-hop-self neighbor 10.1.1.10 send-community neighbor 10.1.1.10 distribute-list 1 out ...... ! access-list 1 deny 192.168.196.0 access-list 1 permit any 2.prefix-list前缀列表过滤
命令： ip prefix-list 列表号 [seq 序号] {deny | permit} 网络号/len匹配长度 [ge 最小匹配值] [le 最大匹配值] 其中： len < ge <= le 如果存在ge和le，则len匹配长度将会被忽略 应用： neighbor 邻居 prefix-list 名称 [in | out] 注意：prefix-list和distribute-list不能同时应用在同一个邻居上，但distribute-list可以调用prefix-list定义的列表 例如： router bgp 100 aggregate-address 192.168.192.0 255.255.248.0 suppress-map supmap neighbor 10.1.1.1 remote-as 50 neighbor 10.1.1.5 remote-as 200 neighbor 10.1.1.10 remote-as 100 neighbor 10.1.1.10 next-hop-self neighbor 10.1.1.10 send-community neighbor 10.1.1.10 prefix-list cisco out ...... ! ip prefix-list cisco seq 5 permit 192.168.192.0/21 ge 22 le 24 r3#show ip bgp
BGP table version is 17, local router ID is 3.3.3.3 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path
s> 192.168.192.0 10.1.1.1 0 0 50 i *> 192.168.192.0/21 0.0.0.0 32768 i *> 192.168.193.0 10.1.1.1 0 0 50 i *> 192.168.194.0 10.1.1.1 0 0 50 i *> 192.168.196.0 10.1.1.5 0 0 200 i s> 192.168.197.0 10.1.1.5 0 0 200 i *> 192.168.198.0 10.1.1.5 0 0 200 i *>i200.200.200.0 10.1.1.10 0 100 0 i 3.AS-PATH过滤
命令： ip as-path access-list 编号 { permit | deny } 正则表达式 其中表达式的原则： . 任何单一字符，包括空格 [] 在方括号中罗列的任何字符 [^] 除了在方括号中所罗列字符外的任何字符（^必须放在字符列表之前） - （连字符）在由连字符所分配的两个字符之间的任意字符 ？ 字符或模式出现 0次或 1次 * 字符或模式出现 0次或多次 + 字符或模式出现 1次或多次 ^ 一行的开始 $ 一行的结束 | 由元字符特殊字符分隔的字之一 _ （下划线）一个逗号，行的开始，行的结束或空格 例如： ip as-path access-list 1 permit ^(850|860)*$ 将在AS-PATH中匹配重复多次的AS号为850或860列表，如（850），（850，850，850），（850，850，888）或（860），（860，860，860）等 应用： neighbor 邻居 filter-list as-path定义的编号 [ in | out ] 案例： r4#show ip bgp BGP table version is 16, local router ID is 200.200.200.201 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path
*>i192.168.193.0 10.1.1.9 0 100 0 50 i *>i192.168.194.0 10.1.1.9 0 100 0 50 i *>i192.168.196.0 10.1.1.9 0 100 0 200 i *>i192.168.198.0 10.1.1.9 0 100 0 200 i *> 200.200.200.0 0.0.0.0 0 32768 i r3上修改 router bgp 100 ...... neighbor 10.1.1.10 remote-as 100 neighbor 10.1.1.10 next-hop-self neighbor 10.1.1.10 send-community neighbor 10.1.1.10 filter-list 1 out no auto-summary ! ip as-path access-list 1 permit ^50$ //只允许as号为50的通过 r4#show ip bgp
BGP table version is 22, local router ID is 200.200.200.201 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path
*>i192.168.193.0 10.1.1.9 0 100 0 50 i *>i192.168.194.0 10.1.1.9 0 100 0 50 i *> 200.200.200.0 0.0.0.0 0 32768 i 4.route-map过滤：
命令： route-map 名称 [permit | deny ] 编号 match 匹配 应用： neighbor 邻居 route-map 名称 案例： router bgp 100 ...... neighbor 10.1.1.10 remote-as 100 neighbor 10.1.1.10 next-hop-self neighbor 10.1.1.10 send-community neighbor 10.1.1.10 route-map mapcisco out no auto-summary ! ip as-path access-list 1 permit ^50$ access-list 1 permit 192.168.193.0 access-list 1 permit 192.168.195.0 route-map mapcisco permit 10 match ip address 1 r4#show ip bgp
BGP table version is 22, local router ID is 200.200.200.201 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete Network Next Hop Metric LocPrf Weight Path *>i192.168.193.0 10.1.1.9 0 100 0 50 i *>i192.168.194.0 10.1.1.9 0 100 0 50 i *> 200.200.200.0 0.0.0.0 0 32768 i ---------------------------------------------------------------------------------- 本文出自 “无聊生活，积极面对” 博客，谢绝转载！ 本文出自 51CTO.COM技术博客 |
hello_me
博客统计信息
热门文章
最新评论
友情链接
