如何配置FortiGate BGP路由聚合
2012-12-21 16:55:13   来源：   评论：0 点击：

1、文档用途

本文描述的是如何配置BGP协议的路由会聚功能从而通过宣告聚合路由来达到通告多条详细路由的具体步骤。

2、适应范围

所有的运行在NAT模式下面的FortiGate或VDOM。

3、预期结果

本文将把如下三条详细路由通过BGP会聚功能通告成聚合路由：* 10.162.0.0/16
 * 10.162.0.0/255.255.254.0
 * 10.162.2.0/255.255.254.0
* 10.162.4.0/255.255.254.0

4、具体配置

具体配置如下显示，名称FGT-AS162是本地FortiGate：
FGT-AS162 (bgp) # show
config router bgp
        config aggregate-address
            edit 1
                set prefix 10.162.0.0 255.255.0.0
                set summary-only enable
            next
        end
    set as 162
        config neighbor
            edit 10.142.0.110
                set remote-as 1
            next
        end
        config network
            edit 1
                set prefix 10.162.0.0 255.255.254.0
            next
            edit 2
                set prefix 10.162.2.0 255.255.254.0
            next
            edit 3
                set prefix 10.162.4.0 255.255.254.0
            next
        end
        config redistribute "connected"
        end
        config redistribute "rip"
        end
        config redistribute "ospf"
        end
        config redistribute "static"
        end
set router-id 10.142.0.114
end

5、配置验证

名称FGT_ISP是模拟的ISP边界路由器：
FGT-AS162启用了BGP路由聚合功能

5．1 在FGT-AS162上验证

FGT-AS162 # get router info routing-table all
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
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

S* 0.0.0.0/0 [10/0] via 192.168.183.254, port1
B 1.1.1.1/32 [20/0] via 10.142.0.110, port2, 01:03:29
C 10.142.0.0/23 is directly connected, port2
B 10.160.0.0/23 [20/0] via 10.142.0.110, port2, 00:02:07
B 10.162.0.0/16 [20/0] is a summary, Null, 00:12:16
C 10.162.0.0/23 is directly connected, port3
C 10.162.2.0/23 is directly connected, port5
C 10.162.4.0/23 is directly connected, port6
B 192.168.0.0/16 [20/0] via 10.142.0.110, port2, 01:03:29
B 192.168.0.0/21 [20/0] via 10.142.0.205, port2, 01:03:29
B 192.168.168.0/24 [20/0] via 10.142.0.110, port2, 01:03:29
C 192.168.182.0/23 is directly connected, port1

可以看到上面路由表里面有条“null”的路由可以避免路由环路产生

FGT-AS162 # get router info bgp network
BGP table version is 9, local router ID is 10.142.0.114
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
S Stale
Origin codes: i - IGP, e - EGP,   - incomplete

Network Next Hop Metric LocPrf Weight Path
*> 1.1.1.1/32 10.142.0.110 0 0 1  
*> 10.160.0.0/23 10.142.0.110 0 0 1 i
*> 10.162.0.0/16 0.0.0.0 32768 i <<<< 这就是将要通过BGP宣告出去的路由
s> 10.162.0.0/23 0.0.0.0 100 32768 i
s> 10.162.2.0/23 0.0.0.0 100 32768 i
s> 10.162.4.0/23 0.0.0.0 100 32768 i
*> 192.168.0.0/16 10.142.0.110 0 0 1  
*> 192.168.0.0/21 10.142.0.205 0 0 1 2 i
*> 192.168.168.0 10.142.0.110 0 0 1  
Total number of prefixes 9

可以看到BGP摘要路由下面有三条路由有 's' 标记，指的是摘要路由来源于这3条详细路由。

5．2 在FGT_ISP上验证

Network            Next Hop          Metric LocPrf Weight Path
*> 1.1.1.1/32       192.168.183.254                    32768  
*> 10.160.0.0/23    0.0.0.0                       100  32768 i
*> 10.162.0.0/16    10.142.0.114             0             0 162 i
*> 192.168.0.0/16   192.168.183.254                    32768  
*> 192.168.0.0/21   10.142.0.205             0             0 2 i
*> 192.168.168.0    192.168.183.254                    32768     Total number of prefixes 6   FGT_ISP (bgp) # get router info routing-table all
Codes: K - kernel, C - connected, S - static, R - RIP, B - BGP
       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 S       1.1.1.1/32 [10/0] via 192.168.183.254, port1
C       10.142.0.0/23 is directly connected, port6
C       10.160.0.0/23 is directly connected, port2
B       10.162.0.0/16 [20/0] via 10.142.0.114, port6, 01:04:08
这条就是BGP对端宣告过来的摘要路由
S       192.168.0.0/16 [10/0] via 192.168.183.254, port1
B       192.168.0.0/21 [20/0] via 10.142.0.205, port6, 19:30:25
S       192.168.168.0/24 [10/0] via 192.168.183.254, port1
C       192.168.182.0/23 is directly connected, port1