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本文档介绍如何使用set ip default next-hop和set ip next-hop命令配置基于策略的路由(PBR)。
本文档没有任何特定的要求。
本文档中的信息基于支持基于策略的路由的软件。
可以使用Cisco Feature Navigator确定此配置支持的硬件和软件。
注意:只有思科注册用户才能访问内部工具和信息。
本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始(默认)配置。如果您的网络处于活动状态,请确保您了解所有命令的潜在影响。
有关文档规则的详细信息,请参阅 Cisco 技术提示规则。
本文档提供了使用set ip default next-hop和set ip next-hop命令配置基于策略的路由(PBR)的示例。
set ip default next-hop命令验证目标IP地址在路由表中是否存在,以及:
如果目标 IP 地址存在,则该命令不对数据包进行策略路由,而是基于路由表转发数据包。
如果目标IP地址不存在,命令策略会路由数据包并将其发送到指定的下一跳。
set ip next-hop命令验证指定的下一跳是否存在,以及:
如果下一跳在路由表中存在,则该命令将数据包策略路由到下一跳。
本节提供配置本文档中所述功能的信息。
本文档使用以下网络设置:
本部分使用以下配置:
R1 |
---|
R1#show running-config Building configuration... ! ! interface Ethernet0/0 ip address 10.100.100.1 255.255.255.0 ip policy route-map blah ! interface Serial1/0 ip address 10.10.10.1 255.255.255.0 ! interface Serial2/0 ip address 10.20.20.1 255.255.255.0 ! router ospf 1 !--- OSPF is not configured on Serial1/0. log-adjacency-changes network 10.20.20.0 0.0.0.255 area 0 network 10.100.100.0 0.0.0.255 area 0 ! ip classless no ip http server ! access-list 100 permit ip host 10.100.100.3 host 10.200.200.4 ! route-map blah permit 10 match ip address 100 set ip default next-hop 10.10.10.2 ! end |
R2 |
---|
R2#show running-config Building configuration... ! ! interface Ethernet0/0 ip address 10.200.200.2 255.255.255.0 ip policy route-map blah ! interface Serial1/0 ip address 10.10.10.2 255.255.255.0 fair-queue ! interface Serial2/0 ip address 10.20.20.2 255.255.255.0 ! router ospf 1 !--- OSPF is not configured on Serial1/0. log-adjacency-changes network 10.20.20.0 0.0.0.255 area 0 network 10.200.200.0 0.0.0.255 area 0 ! ip classless no ip http server ! access-list 100 permit ip host 10.200.200.4 host 10.100.100.3 ! route-map blah permit 10 match ip address 100 set ip default next-hop 10.10.10.1 ! end |
使用set ip default next-hop命令时,当路由表中存在目标路由时,将使用正常转发—不要对数据包进行策略路由。
R1#show ip route 10.200.200.4 Routing entry for 10.200.200.0/24 Known via "ospf 1", distance 110, metric 74, type intra area Last update from 10.20.20.2 on Serial2/0, 00:11:48 ago Routing Descriptor Blocks: * 10.20.20.2, from 10.30.30.3, 00:11:48 ago, via Serial2/0 Route metric is 74, traffic share count is 1 R1#debug ip policy Policy routing debugging is on *Dec 4 12:50:57.363: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 4 12:50:57.363: IP: route map blah, item 10, permit *Dec 4 12:50:57.363: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0), len 100, policy rejected -- normal forwarding *Dec 4 12:50:57.431: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 4 12:50:57.431: IP: route map blah, item 10, permit *Dec 4 12:50:57.431: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0), len 100, policy rejected -- normal forwarding *Dec 4 12:50:57.491: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 4 12:50:57.491: IP: route map blah, item 10, permit *Dec 4 12:50:57.491: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0), len 100, policy rejected -- normal forwarding R2#show ip route 10.100.100.3 Routing entry for 10.100.100.0/24 Known via "ospf 1", distance 110, metric 74, type intra area Last update from 10.20.20.1 on Serial2/0, 00:11:42 ago Routing Descriptor Blocks: * 10.20.20.1, from 10.100.100.1, 00:11:42 ago, via Serial2/0 Route metric is 74, traffic share count is 1 R2#debug ip policy Policy routing debugging is on *Dec 4 12:50:57.779: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3, len 100, policy match *Dec 4 12:50:57.779: IP: route map blah, item 10, permit *Dec 4 12:50:57.779: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3 (Serial2/0), len 100, policy rejected -- normal forwarding *Dec 4 12:50:57.839: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3, len 100, policy match *Dec 4 12:50:57.839: IP: route map blah, item 10, permit *Dec 4 12:50:57.839: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3 (Serial2/0), len 100, policy rejected -- normal forwarding *Dec 4 12:50:57.911: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3, len 100, policy match *Dec 4 12:50:57.911: IP: route map blah, item 10, permit *Dec 4 12:50:57.911: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3 (Serial2/0), len 100, policy rejected -- normal forwarding
Serial 2/0 关闭并且目标地址从路由表消失时,对数据包进行策略路由。
R1#show ip route 10.200.200.0 % Network not in table R1# *Dec 5 13:26:27.567: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:26:27.567: IP: route map blah, item 10, permit *Dec 5 13:26:27.567: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:26:27.567: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 5 13:26:27.655: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:26:27.655: IP: route map blah, item 10, permit *Dec 5 13:26:27.655: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:26:27.655: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 5 13:26:27.727: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:26:27.727: IP: route map blah, item 10, permit *Dec 5 13:26:27.727: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:26:27.727: IP: Ethernet0/0 to Serial1/0 10.10.10.2
本部分使用以下配置:
R1 |
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R1#show running-config Building configuration... ! |
R2 |
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R2#show running-config Building configuration... ! |
通过使用命令set ip next-hop,路由器验证路由表中是否存在下一跳10.10.10.2。如果目的路由在路由表中存在,则下一跳可访问时对数据包进行策略路由。
R1#show ip route 10.10.10.2Routing entry for 10.10.10.0/24 Known via "connected", distance 0, metric 0 (connected, via interface) Routing Descriptor Blocks: * directly connected, via Serial1/0 Route metric is 0, traffic share count is 1
R1#show ip route 10.200.200.4
Routing entry for 10.200.200.0/24
Known via "ospf 1", distance 110, metric 74,
type intra area Last update from 10.20.20.2 on Serial2/0, 00:11:48 ago
Routing Descriptor Blocks: * 10.20.20.2, from 10.30.30.3, 00:11:48 ago,
via Serial2/0 Route metric is 74, traffic share count is 1
R1#debug ip policy Policy routing debugging is on
*Dec 4 12:53:38.271: IP: s=10.100.100.3 (Ethernet0/0), d=10.200.200.4, len 100, policy match
*Dec 4 12:53:38.271: IP: route map blah, item 10, permit
*Dec 4 12:53:38.271: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0), len 100, policy routed *Dec 4 12:53:38.271:
IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 4 12:53:38.355:
IP: s=10.100.100.3 (Ethernet0/0), d=10.200.200.4, len 100, policy match *Dec 4 12:53:38.355:
IP: route map blah, item 10, permit *Dec 4 12:53:38.355:
IP: s=10.100.100.3 (Ethernet0/0), d=10.200.200.4 (Serial1/0), len 100, policy routed
*Dec 4 12:53:38.355: IP: Ethernet0/0 to Serial1/0 10.10.10.2
*Dec 4 12:53:38.483: IP: s=10.100.100.3 (Ethernet0/0), d=10.200.200.4, len 100, policy match
*Dec 4 12:53:38.483: IP: route map blah, item 10, permit
R2#show ip route 10.100.100.3 Routing entry for 10.100.100.0/24 Known via "ospf 1",
distance 110, metric 74, type intra area Last update from 10.20.20.1 on Serial2/0,
00:11:42 ago Routing Descriptor Blocks: * 10.20.20.1, from 10.100.100.1, 00:11:42 ago,
via Serial2/0 Route metric is 74, traffic share count is 1 R2#debug ip policy
Policy routing debugging is on *Dec 4 12:53:38.691:
IP: s=10.200.200.4 (Ethernet0/0), d=10.100.100.3, len 100, policy match *Dec 4 12:53:38.691:
IP: route map blah, item 10, permit *Dec 4 12:53:38.691: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3 (Serial1/0), len 100, policy routed
*Dec 4 12:53:38.691: IP: Ethernet0/0 to Serial1/0 10.10.10.1 *Dec 4 12:53:38.799:
IP: s=10.200.200.4 (Ethernet0/0), d=10.100.100.3, len 100, policy match
*Dec 4 12:53:38.799: IP: route map blah, item 10, permit
*Dec 4 12:53:38.799: IP: s=10.200.200.4 (Ethernet0/0), d=10.100.100.3 (Serial1/0), len 100, policy routed
*Dec 4 12:53:38.799: IP: Ethernet0/0 to Serial1/0 10.10.10.1 *Dec 4 12:53:38.899:
IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3, len 100, policy match
*Dec 4 12:53:38.899: IP: route map blah, item 10, permit
目标 IP 地址从路由消失时,对数据包进行策略路由。
*Dec 5 13:33:23.607: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:33:23.607: IP: route map blah, item 10, permit *Dec 5 13:33:23.607: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:33:23.607: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 5 13:33:23.707: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:33:23.707: IP: route map blah, item 10, permit *Dec 5 13:33:23.707: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:33:23.707: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 5 13:33:23.847: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:33:23.847: IP: route map blah, item 10, permit
当Serial 1/0接口断开时,路由表中将丢失下一跳10.10.10.2,数据包将跟踪正常的路由表。
*Dec 5 13:40:38.887: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:40:38.887: IP: route map blah, item 10, permit *Dec 5 13:40:38.887: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0), len 100, policy rejected -- normal forwarding *Dec 5 13:40:39.047: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:40:39.047: IP: route map blah, item 10, permit *Dec 5 13:40:39.047: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0), len 100, policy rejected -- normal forwarding *Dec 5 13:40:39.115: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:40:39.115: IP: route map blah, item 10, permit *Dec 5 13:40:39.115: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0), len 100, policy rejected -- normal forwarding
本部分使用以下配置:
R1 |
---|
R1#show running-config Building configuration... ! |
R2 |
---|
R2#show running-config Building configuration... ! ! interface Ethernet0/0 ip address 10.200.200.2 255.255.255.0 ip policy route-map blah ! interface Serial1/0 ip address 10.10.10.2 255.255.255.0 fair-queue ! interface Serial2/0 ip address 10.20.20.2 255.255.255.0 ! ip route 0.0.0.0 0.0.0.0 10.20.20.1 ! ip classless no ip http server ! ! ! access-list 100 permit ip host 10.200.200.4 host 10.100.100.3 ! route-map blah permit 10 match ip address 100 set ip default next-hop 10.10.10.1 ! end |
使用set ip default next-hop命令时,当到目标的唯一路由是默认路由(路由表中没有到该目标的特定路由)时,将对数据包进行策略路由。
R1#show ip route 10.200.200.4 % Network not in table R1# R1#show ip route 0.0.0.0 Routing entry for 0.0.0.0/0, supernet Known via "static", distance 1, metric 0, candidate default path Routing Descriptor Blocks: * 10.20.20.2 Route metric is 0, traffic share count is 1 R1# *Dec 4 12:58:55.191: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 4 12:58:55.191: IP: route map blah, item 10, permit *Dec 4 12:58:55.191: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0), len 100, policy routed *Dec 4 12:58:55.191: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 4 12:58:55.291: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 4 12:58:55.291: IP: route map blah, item 10, permit *Dec 4 12:58:55.291: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0), len 100, policy routed *Dec 4 12:58:55.291: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 4 12:58:55.391: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 4 12:58:55.391: IP: route map blah, item 10, permit *Dec 4 12:58:55.391: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0), len 100, policy routed *Dec 4 12:58:55.391: IP: Ethernet0/0 to Serial1/0 10.10.10.2 R2#show ip route 10.100.100.3 % Network not in table R2#show ip route 0.0.0.0 Routing entry for 0.0.0.0/0, supernet Known via "static", distance 1, metric 0, candidate default path Routing Descriptor Blocks: * 10.20.20.1 Route metric is 0, traffic share count is 1 R2# *Dec 4 12:58:20.819: %SYS-5-CONFIG_I: Configured from console by console *Dec 4 12:58:55.611: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3, len 100, policy match *Dec 4 12:58:55.611: IP: route map blah, item 10, permit *Dec 4 12:58:55.611: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3 (Serial1/0), len 100, policy routed *Dec 4 12:58:55.611: IP: Ethernet0/0 to Serial1/0 10.10.10.1 *Dec 4 12:58:55.739: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3, len 100, policy match *Dec 4 12:58:55.739: IP: route map blah, item 10, permit *Dec 4 12:58:55.739: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3 (Serial1/0), len 100, policy routed *Dec 4 12:58:55.739: IP: Ethernet0/0 to Serial1/0 10.10.10.1 *Dec 4 12:58:55.799: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3, len 100, policy match *Dec 4 12:58:55.799: IP: route map blah, item 10, permit *Dec 4 12:58:55.799: IP: s=10.200.200.4 (Ethernet0/0),
d=10.100.100.3 (Serial1/0), len 100, policy routed *Dec 4 12:58:55.799: IP: Ethernet0/0 to Serial1/0 10.10.10.1
默认路由由于 Serial 2/0 关闭而不存在时,对数据包进行策略路由。
R1#show ip route 0.0.0.0 % Network not in table R1# *Dec 5 13:02:31.283: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:02:31.283: IP: route map blah, item 10, permit *Dec 5 13:02:31.283: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:02:31.283: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 5 13:02:31.375: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:02:31.375: IP: route map blah, item 10, permit *Dec 5 13:02:31.375: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:02:31.375: IP: Ethernet0/0 to Serial1/0 10.10.10.2 *Dec 5 13:02:31.435: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 13:02:31.435: IP: route map blah, item 10, permit *Dec 5 13:02:31.435: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial1/0),len 100, policy routed *Dec 5 13:02:31.435: IP: Ethernet0/0 to Serial1/0 10.10.10.2
在Serial2/0开启且Serial 1/0关闭的情况下,您将丢失下一跳,数据包将跟踪正常转发(路由表)-策略已拒绝。
R1#debug ip policy Policy routing debugging is on R1# *Dec 5 12:46:49.543: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 12:46:49.543: IP: route map blah, item 10, permit *Dec 5 12:46:49.543: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0),len 100, policy rejected -- normal forwarding *Dec 5 12:46:49.623: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 12:46:49.623: IP: route map blah, item 10, permit *Dec 5 12:46:49.623: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0),len 100, policy rejected -- normal forwarding *Dec 5 12:46:49.691: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4, len 100, policy match *Dec 5 12:46:49.691: IP: route map blah, item 10, permit *Dec 5 12:46:49.691: IP: s=10.100.100.3 (Ethernet0/0),
d=10.200.200.4 (Serial2/0),len 100, policy rejected -- normal forwarding
版本 | 发布日期 | 备注 |
---|---|---|
2.0 |
20-Nov-2023 |
重新认证 |
1.0 |
05-Dec-2003 |
初始版本 |