04-02-2010 02:11 PM - edited 03-04-2019 08:00 AM
Imagine my goal is to advertise a summarized prefix 10.177.206.0/23 which represents 10.177.206.0/24 and 10.177.207.0/24 networks.
Then I wrote the below. However, the ISP still sees 10.177.207.0/24 and 10.177.206.0/24 instead of only one summarized entry 10.177.206.0/23 as I
wish.
Given that I do not have a more specific routing in the bgp table for networks 10.177.206.0 and 10.177.207.0, that means the aggregate-address is not working for me, if I understand this correctly.
Question:
Is there any way to make this aggregate command work in my case or do I need to rely on individual network statements advertising 10.177.206.0/24 and 10.177.207.0/24?
R2#show run | b bgp
router bgp 100
no synchronization
bgp log-neighbor-changes
network 10.177.206.0 mask 255.255.255.0
network 10.177.207.0 mask 255.255.255.0
aggregate-address 10.177.206.0 255.255.255.254 summary-only
R2#show ip bgp
BGP table version is 6, local router ID is 10.2.255.32
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*> 4.4.4.4/32 10.2.47.193 0 0 200 i
R2#
R2#show ip route | i 10.177.20
O 10.2.95.1/32 [110/2] via 10.177.206.1, 00:19:09, FastEthernet2/0
O 10.2.80.0/24 [110/2] via 10.177.206.1, 00:19:09, FastEthernet2/0
O 10.177.220.0/24 [110/2] via 10.177.206.1, 00:19:09, FastEthernet2/0
O 10.177.207.0/24 [110/2] via 10.177.206.1, 00:19:09, FastEthernet2/0
C 10.177.206.0/24 is directly connected, FastEthernet2/0
O 10.2.255.47/32 [110/3] via 10.177.206.1, 00:19:09, FastEthernet2/0
O 192.168.1.1 [110/2] via 10.177.206.1, 00:19:09, FastEthernet2/0
ISP is seeing:
Gateway of last resort is not set
4.0.0.0/32 is subnetted, 1 subnets
C 4.4.4.4 is directly connected, Loopback0
10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C 10.2.55.0/24 is directly connected, FastEthernet0/0
B 10.177.207.0/24 [20/2] via 10.2.47.204, 00:01:04
B 10.177.206.0/24 [20/0] via 10.2.47.204, 00:01:04
C 10.2.47.192/28 is directly connected, FastEthernet1/0
Solved! Go to Solution.
04-02-2010 02:16 PM
Marlon
You have the wrong mask ie.
aggregate-address 10.177.206.0 255.255.255.254 summary-only
should be
aggregate-address 10.177.206.0 255.255.254.0 summary-only
Also do you have either 10.177.206.0/24 or 10.177.207.0/24 in your routing table without the network statements ?
If not you only need to have one network statement under BGP for one of the networks.
Jon
04-02-2010 02:16 PM
Marlon
You have the wrong mask ie.
aggregate-address 10.177.206.0 255.255.255.254 summary-only
should be
aggregate-address 10.177.206.0 255.255.254.0 summary-only
Also do you have either 10.177.206.0/24 or 10.177.207.0/24 in your routing table without the network statements ?
If not you only need to have one network statement under BGP for one of the networks.
Jon
04-03-2010 10:24 PM
10.177.206.0/24 seems to be a connected route on an interface.
10.177.207.0/24 is learned via OSPF.
Does the OP still need to have a network statement, or can he just aggregate both into a summary, since they're already in the RIB?
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