Description
This article describes the steps to announce multiple routes with one summary route in BGP.
Scope
All FortiGate or VDOM running in NAT mode.
Diagram
Expectations, Requirements
In this article is the summary of the following connected networks:
* 10.162.0.0/255.255.254.0
* 10.162.2.0/255.255.254.0
* 10.162.4.0/255.255.254.0
=> As the following summarized route:
* 10.162.0.0/16
Configuration
FGT-AS162 is the FortiGate on which is the configuration of the route summary.
# 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
Verification
FGT_ISP is ISP's border router.
FGT-AS162 is the FortiGate on which is the configuration to the route summary.
The following commands will be used:
# get router info bgp summary
# get router info bgp neighbors
# get router info bgp network
# get router info routing-table all
FGT-AS162
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
See above the null route in the routing table in order to prevent routing loops.
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 <<<< THIS IS THE SUMMARY THAT WILL BE SENT
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
See above the 's' letter that is preceding each route that is suppressed by BGP.
FGT_ISP
FGT_ISP (bgp) # get router info bgp network
BGP table version is 18, local router ID is 10.142.0.110
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
*> 1.1.1.1/32 192.168.183.254 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 <<<< THIS IS THE SUMMARY RECEIVED ON THE PEER
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
Troubleshooting
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