do you mean the DataCenter recieves the Default rotue thrugh IBGP thorugh colo site , and yo want the datacneter sees this defaukt route from diffrent next hop or in other words when its forwarded to the colo its get forwarded to other next hop than the one used by colo ?
i think this is a bit tricky becuase routing works hop by hop if the datacneter forward the route route to the colo then colo will use its routing table to forward the traffic
i think you may try VRFs and vrfs route leaking
allthe config in colo router
the idea is to put the link connected to the datacenter in a vrf and other links in diffrent vrf and you you will use will use inport and export through route-target between vrfs but you can now controll what default route from what next hop you will use for the datacenter vrf
kets say the dataceneter VRF called DC and other called VRF1
ip vrf DC -- datacnter VRF
rd 1:1
route-target export 1:1
route-target import 1:1
!
ip vrf VRF1 ---other lniks VRF
rd 2:2
export map DC - ths map will xort all route Except the defult rouete to DC VRF
route-target export 2:2
route-target import 2:2
route-target import 1:1 --- thisto imort te rute from DC
!
interface Loopback0
ip address 1.1.1.1 255.255.255.0
!
interface FastEthernet1/0
ip vrf forwarding DC
ip address 10.1.1.1 255.255.255.0
!
interface FastEthernet1/1
ip vrf forwarding VRF1
ip address 192.168.1.1 255.255.255.0
!
interface FastEthernet2/0
ip vrf forwarding VRF1 you can hae one llink conected to two BGPpeers in te sae subnet ( in this exmple i hav two diffrent interfaces
ip address 30.1.1.1 255.255.255.0
!
router eigrp 10
auto-summary
!
address-family ipv4 vrf VRF1 fo reirp oute with other sites
network 0.0.0.0
no auto-summary
autonomous-system 10
exit-address-family
!
address-family ipv4 vrf DC --- eirp with D over DC f
redistribute bgp 65002 metric 1 1 1 1 1 toredisrbute the bellow static deault route
network 0.0.0.0
no auto-summary
autonomous-system 10
exit-address-family
!
router bgp 65002
no synchronization
bgp log-neighbor-changes
no auto-summary
!
address-family ipv4 vrf VRF1
redistribute connected
neighbor 30.1.1.3 remote-as 65000
neighbor 30.1.1.3 activate
neighbor 192.168.1.2 remote-as 65001
neighbor 192.168.1.2 activate
no synchronization
exit-address-family
!
address-family ipv4 vrf DC
redistribute connected
redistribute static --- this to inject the defalt route into bgp under DC VRF this will be used by Colo rotr under DC vrf toend the trafi according to this defaultroute stati entry
redistribute eigrp 10
neighbor 10.1.1.10 remote-as 65002
neighbor 10.1.1.10 activate
neighbor 10.1.1.10 default-originate -- -thito inject defaulte to DC through BGP
no synchronization
exit-address-family
!
ip forward-protocol nd
ip route vrf DC 0.0.0.0 0.0.0.0 30.1.1.3 - efalte-route to be used ove e desidred next hop
no ip http server
no ip http secure-server
!
!
!
!
ip prefix-list DC seq 5 deny 0.0.0.0/0 this to exort all routs to DC except the deautl becuase we need to use the stat route above
ip prefix-list DC seq 10 permit 0.0.0.0/0 le 32
logging alarm informational
!
!
!
route-map DC permit 10
match ip address prefix-list DC
set extcommunity rt 1:1 additive -- set the reqired R t e sen b DC VRF
!
!
DC router:
R0#show ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, 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, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is 10.1.1.1 to network 0.0.0.0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, FastEthernet1/0
D 192.168.1.0/24 [90/30720] via 10.1.1.1, 00:00:01, FastEthernet1/0
150.1.0.0/24 is subnetted, 1 subnets
C 150.1.1.0 is directly connected, Loopback0
30.0.0.0/24 is subnetted, 1 subnets
D 30.1.1.0 [90/30720] via 10.1.1.1, 00:00:01, FastEthernet1/0
B* 0.0.0.0/0 [200/0] via 10.1.1.1, 00:01:00 -- this from clo inyour case
thisrepresent the colo router:
R1#show ip route vrf VRF1
Routing Table: VRF1
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, 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, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is 192.168.1.2 to network 0.0.0.0
2.0.0.0/24 is subnetted, 1 subnets
D 2.2.2.0 [90/156160] via 192.168.1.2, 00:08:32, FastEthernet1/1
20.0.0.0/24 is subnetted, 1 subnets
D 20.1.1.0 [90/30720] via 192.168.1.2, 00:08:20, FastEthernet1/1
D 192.168.4.0/24 [90/30720] via 30.1.1.3, 00:00:39, FastEthernet2/0
10.0.0.0/24 is subnetted, 1 subnets
B 10.1.1.0 is directly connected, 00:05:47, FastEthernet1/0
C 192.168.1.0/24 is directly connected, FastEthernet1/1
150.1.0.0/24 is subnetted, 1 subnets
B 150.1.1.0 [20/156160] via 10.1.1.10 (DC), 00:05:47, FastEthernet1/0
30.0.0.0/24 is subnetted, 1 subnets
C 30.1.1.0 is directly connected, FastEthernet2/0
B* 0.0.0.0/0 [20/0] via 192.168.1.2, 00:06:14 lo the next op of the defatl route and also other DC routes seenthugh bgp becuase ty are importe via VRF
bellw D VRF routing table
R1#show ip route vrf DC
Routing Table: DC
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, 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, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route
Gateway of last resort is 30.1.1.1 to network 0.0.0.0
10.0.0.0/24 is subnetted, 1 subnets
C 10.1.1.0 is directly connected, FastEthernet1/0
B 192.168.1.0/24 is directly connected, 00:06:40, FastEthernet1/1
150.1.0.0/24 is subnetted, 1 subnets
D 150.1.1.0 [90/156160] via 10.1.1.10, 00:12:13, FastEthernet1/0
30.0.0.0/24 is subnetted, 1 subnets
B 30.1.1.0 is directly connected, 00:06:40, FastEthernet2/0
S* 0.0.0.0/0 [1/0] via 30.1.1.3 the default route now is other peer based onthe static route above
now DC send the defaultroute to colo and colo will use DC vrf routing table and send it to 30.1.1.3
good luck
if helpful Rate
