route-policy-路由策略规则详解.docx

ROUTE-POLICY 路由策略 规则详解 在实际工程中经常用到route-policy的情况，下面对route-policy和ACL的详细匹配规则做以说明：一、 标准访问列表：#acl number 2000rule 0 permit source 55此类ACL用于route-policy时做前缀匹配，即路由条目和规则条目做 AND 运算 ，结果落在反掩码的包含范围之内的则匹配成功。对于上述配置：/24 /25 /30 等均可匹配，但是/16 等则匹配不成功。二、 扩展访问列表：#acl number 3000rule 0 permit ip source 0 destination 0acl number 3001rule 0 deny ip source 0 destination 0此类ACL比较特殊，源和目的的掩码均要为0 。用于route-policy 是要做严格的匹配，即前缀要和source 匹配，前缀的掩码部分要和destination匹配。对于上述配置3000来说，则只有/24可与之匹配。此类列表和Route-policy配合可用于严格的匹配一条路由条目。三、 permit+permit的route-policy#route-policy t1 permit node 10if-match acl 3000apply local-preference 1300 route-policy t1 permit node 20对于route-policy的permit规则来说，凡是能够匹配ACL permit规则的条目就执行node 10中的apply 规则，并不再继续匹配下面的规则。不能够匹配ACL permit规则的条目，就继续执行下一个 node 20中的相应规则。对于上述配置的结果是/24匹配node 10 被修改LP属性为1300 ，而/24 则匹配node 20 不做任何修改。2个条目都可以通告。AR2810-Bdis bgp routingFlags:# - valid - active I - internal D - damped H - history S - aggregate suppressed Dest/Mask Next-Hop Med Local-pref Origin Path -#I 0 1300 IGP #I 0 100 IGP Routes total: 2AR2810-B四、 permit+deny 的route-policy#route-policy t2 permit node 10if-match acl 3001apply local-preference 2300route-policy t2 permit node 20对于route-policy 的permit规则来说，凡是明确和ACL 的deny 规则匹配的则不执行node 10中的apply规则。并且会继续执行下一个node 20 进行匹配 。对于上述配置的结果是：/24 和node 10 匹配，被 DENY 。但是会继续和后面的nod 20 匹配 。上述规则/24 /24条目都可被通告。AR2810-Bdis bgp routingFlags:# - valid - active I - internal D - damped H - history S - aggregate suppressed Dest/Mask Next-Hop Med Local-pref Origin Path -#I 0 100 IGP #I 0 100 IGP Routes total: 2AR2810-B五、 deny+permit 的route-policy#route-policy t3 deny node 10if-match acl 3000apply local-preference 1300 route-policy t3 permit node 20对于route-policy的deny规则来说，凡是和ACL的permit规则匹配的条目都被DENY掉。未匹配的条目则继续向下匹配。对于上述配置的结果是：/24和node 10 匹配，被DENY 掉。而/24则和node 20 匹配。上述规则只有/24可被通告。AR2810-Bdis bgp routingFlags:# - valid - active I - internal D - damped H - history S - aggregate suppressed Dest/Mask Next-Hop Med Local-pref Origin Path -#I 0 100 IGP Routes total: 1AR2810-B六、 deny+deny 的 route-policy#route-policy t4 deny node 10if-match acl 3001apply local-preference 2300route-policy t4 permit node 20对于route-policy的Deny规则来说，凡是和ACL 的deny规则明确匹配的条目被node 10 Deny，并且向下继续匹配后续的规则。这就产生了双重DENY 变成 permit的效果。对于上述配置的结果是：/24 /24 都和node 20匹配。即都可发布。AR2810-Bdis bgp routingFlags:# - valid - active I - internal D - damped H - history S - aggregate suppressed Dest/Mask Next-Hop Med Local-pref Origin Path -#I 0 100 IGP #I 0 100 IGP Routes total: 2AR2810-B对于上述论述总结如下如下：1、route-policy 中的DENY 和applay配合无任何意义。2、凡是在ACL 中被DENY过的条目，可以继续向下匹配。3、在route-policy中被DENY 匹配过的条目则被DENY 不会继续匹配。4、Route-policy用于路由策略时有一个隐含的规则为DENY ALL ，而用于策略路由时则是PERMIT ALL附件1：一、 实验相关信息A (s3/0) -(S3/0) B1）本次测试中用到的设备为H3C AR2810 相关版本及配置信息如下:AR2810-A:AR2810-Adis verHuawei Versatile Routing Platform SoftwareVRP software, Version 3.40, Release 0201P29Copyright (c) 1998-2008 Huawei Technologies Co., Ltd. All rights reserved.Without the owners prior written consent, no decompilingnor reverse-engineering shall be allowed.Quidway AR28-10 uptime is 0 week, 0 day, 1 hour, 13 minutesLast reboot 2008/11/28 06:04:07System returned to ROM By Command.CPU type: PowerPC 8241 200MHz128M bytes SDRAM Memory32M bytes Flash MemoryPCB Version:4.0Logic Version:1.0BootROMVersion:9.23SLOT 0 AUX (Hardware)4.0, (Driver)1.0, (CPLD)1.0SLOT 0 1FE (Hardware)4.0, (Driver)1.0, (CPLD)1.0SLOT 0 WAN (Hardware)4.0, (Driver)1.0, (CPLD)1.0SLOT 3 1SA (Hardware)1.0, (Driver)1.0, (CPLD)2.0AR2810-AvrbdRouting Platform SoftwareVersion AR28-10 8040V300R003B04D040SP73 (COMWAREV300R002B62D014), RELEASE SOFTWARECompiled Oct 22 2008 18:24:10 by jiahuaAR2810-Adis cuAR2810-Adis current-configuration#sysname AR2810-A#acl number 2000rule 0 permit source 55#acl number 3000rule 0 permit ip source 0 destination 0acl number 3001rule 0 deny ip source 0 destination 0#interface Serial3/0link-protocol pppip address 52#bgp 100network network undo synchronizationgroup tolocal internalpeer tolocal route-policy t4 exportpeer group tolocal# route-policy t1 permit node 10if-match acl 3000apply local-preference 1300route-policy t1 permit node 20route-policy t2 permit node 10if-match acl 3001apply local-preference 2300route-policy t2 permit node 20route-policy t3 deny node 10if-match acl 3000apply local-preference 1300route-policy t3 permit node 20route-policy t4 deny node 10if-match acl 3001apply local-preference 2300route-policy t4 permit node 20#ip route-static NULL 0 preference 60ip route-static NULL 0 preference 60AR2810-AAr2810-B:AR2810-Bdis verHuawei Versatile Routing Platform SoftwareVRP software, Version 3.40, Release 0201P29Copyright (c) 1998-2008 Huawei Technologies Co., Ltd. All rights reserved.Without the owners prior written consent, no decompilingnor reverse-engineering shall be allowed.Quidway AR28-10 uptime is 0 week, 0 day, 1 hour, 13 minutesLast reboot 2021/08/22 01:14:25System returned to ROM By Command.CPU type: PowerPC 8241 200MHz128M bytes SDRAM Memory32M bytes Flash MemoryPCB Version:4.0Logic Version:1.0BootROMVersion:9.23SLOT 0 AUX (Hardware)4.0, (Driver)1.0, (CPLD)1.0SLOT 0 1FE (Hardware)4.0, (Driver)1.0, (CPLD)1.0SLOT 0 WAN (Hardware)4.0, (Driver)1.0, (CPLD)1.0SLOT 3 1SA (Hardware)1.0, (Driver)1.0, (CPLD)2.0AR2810-BvrbdRouting Platform SoftwareVersion AR28-10 8040V300R003B04D040SP73 (COMWAREV300R002B62D014), RELEASE SOFTWARECompiled Oct 22 2008 18:24:10 by jiahuaAR2810-B dis cu#sysname AR2810-B#interface Serial3/0clock DTECLK1link-protocol pppip address 52#bgp 100undo synchronizationgroup tolocal internalpeer group tolocal AR2810-B 2）将上述拓扑中的路由器A 替换成CISCO 3640 。再次重复以上试验，得出结论与H3C的route-policy相同。相关CISCO设备版本及配置如下：C3640#show verCisco Internetwork Operating System SoftwareIOS (tm) 3600 Software (C3640-IK9O3S-M), Version 12.2(T10,RELEASE SOFTWARE (fc1)TAC Support:/tacCopyright (c) 1986-2003 by cisco Systems, Inc.Compiled Sat 31-May-03 00:17 by kellythwImage text-base: 0x60008930, data-base: 0x6171C000ROM: System Bootstrap, Version 11.1(20)AA1, EARLY DEPLOYMENT RELEASE SOFTWARE (fc1)C3640 uptime is 16 minutesSystem returned to ROM by reloadSystem image file is flash:c3640-ik9o3s-mz.122-8.t10.bincisco 3640 (R4700) processor (revision 0x00) with 125952K/5120K bytes of memory.Processor board ID 13894963R4700 CPU at 100Mhz, Implementation 33, Rev 1.0Bridging software.X.25 software, Version 3.0.0.SuperLAT software (copyright 1990 by Meridian Technology Corp).5 Ethernet/IEEE 802.3 interface(s)4 Serial network interface(s)DRAM configuration is 64 bits wide with parity disabled.125K bytes of non-volatile configuration memory.16384K bytes of processor board System flash (Read/Write)Configuration register is 0x2102C3640#show running-config!hostname C3640!interface Serial1/1ip address encapsulation ppp