Topology:
Routers R3 and R4 are IOS-XR, remaining routers are IOS routers.
For initial setup, configure loopback0 interfaces on all routers, and links between the routers:
R7-R8: 8.0.78.X/24
R6-R8: 8.0.68.X/24
R5-R8: 8.0.58.X/24
R3-R6: 67.0.36.X/24
R3-R7: 67.0.37.X/24
R1-R5: 5.0.15.X/24
VLAN-10: 12.0.10.X/24
VLAN-20: 12.0.20.X/24
Requirements:
1. Configure iBGP peerings between routers in AS 12.
2. Configure iBGP peerings between routers in AS 67.
3. Configure eBGP peerings between autonomous systems in the topology.
4. Each autonomous system should advertise it's assigned IPv4 network into BGP.
5. On R8, don't use "network" command under BGP configuration.
6. In autonomous-system 12, routers R2 and R4 should advertise the prefix 12.0/16 the BGP.
Solution:
Highlight the text below to reveal the solution.
This is a basic iBGP and eBGP setup, which will use a as base for the next group of tasks.
Note that IOS-XR requires an explicit in and out route-policy for eBGP peerings.
In AS12, eBGP next-hop need to be reachable for routers R2 and R4. This can be achieved by either advertising external interfaces into IGP, or using next-hop-self on iBGP peerings. The recommended method, for the fast convergence, is to advertise eBGP next-hop into IGP. External interfaces are configured as passive in OSPF. Same solution shall be implemented in AS67.
Requirement #5 - since using network command is not allowed, use redistribution of static route into BGP.
!
interface Ethernet0/0
ip address 12.0.20.1 255.255.255.0
ip ospf 1 area 0
!
interface Ethernet1/0
ip address 5.0.15.1 255.255.255.0
ip ospf 1 area 0
!
router bgp 12
bgp log-neighbor-changes
neighbor 5.0.15.5 remote-as 5
neighbor 12.0.2.2 remote-as 12
neighbor 12.0.2.2 update-source Loopback0
neighbor 12.0.3.3 remote-as 12
neighbor 12.0.3.3 update-source Loopback0
neighbor 12.0.4.4 remote-as 12
neighbor 12.0.4.4 update-source Loopback0
!
router ospf 1
router-id 12.0.1.1
passive-interface Ethernet1/0
router bgp 12
bgp log-neighbor-changes
network 12.0.0.0 mask 255.255.0.0
neighbor 12.0.1.1 remote-as 12
neighbor 12.0.1.1 update-source Loopback0
neighbor 12.0.3.3 remote-as 12
neighbor 12.0.3.3 update-source Loopback0
neighbor 12.0.4.4 remote-as 12
neighbor 12.0.4.4 update-source Loopback0
!
router ospf CCIE
router-id 12.0.3.3
area 0
interface Loopback0
!
interface GigabitEthernet0/0/0/0
passive enable
!
interface GigabitEthernet0/0/0/1
passive enable
!
interface GigabitEthernet0/0/0/2
!
!
!
router bgp 12
address-family ipv4 unicast
!
neighbor 12.0.1.1
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.2.2
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.4.4
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 67.0.36.6
remote-as 67
address-family ipv4 unicast
route-policy BGP_ALL in
route-policy BGP_ALL out
!
!
neighbor 67.0.37.7
remote-as 67
address-family ipv4 unicast
route-policy BGP_ALL in
route-policy BGP_ALL out
!
!
!
route-policy BGP_ALL
pass
end-policy
!
router bgp 12
address-family ipv4 unicast
network 12.0.0.0/16
!
neighbor 12.0.1.1
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.2.2
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.3.3
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
!
!
router bgp 5
bgp log-neighbor-changes
network 5.0.0.0 mask 255.255.0.0
neighbor 5.0.15.1 remote-as 12
neighbor 8.0.58.8 remote-as 8
!
interface Ethernet0/0
ip address 67.0.67.6 255.255.255.0
ip router isis CCIE
!
interface Ethernet1/0
ip address 67.0.36.6 255.255.255.0
!
interface Ethernet1/1
ip address 8.0.68.6 255.255.255.0
!
router isis CCIE
net 49.0067.0000.0000.0006.00
passive-interface Ethernet1/0
passive-interface Ethernet1/1
!
router bgp 67
bgp log-neighbor-changes
network 67.0.0.0 mask 255.255.0.0
neighbor 8.0.68.8 remote-as 8
neighbor 67.0.36.3 remote-as 12
neighbor 67.0.67.7 remote-as 67
!
interface Ethernet0/0
ip address 67.0.67.7 255.255.255.0
ip router isis CCIE
!
interface Ethernet1/0
ip address 67.0.37.7 255.255.255.0
!
interface Ethernet1/1
ip address 8.0.78.7 255.255.255.0
!
router isis CCIE
net 49.0067.0000.0000.0007.00
passive-interface Ethernet1/0
passive-interface Ethernet1/1
!
router bgp 67
bgp log-neighbor-changes
network 67.0.0.0 mask 255.255.0.0
neighbor 8.0.78.8 remote-as 8
neighbor 67.0.37.3 remote-as 12
neighbor 67.0.67.6 remote-as 67
!
router bgp 8
bgp log-neighbor-changes
redistribute static route-map STATIC
neighbor 8.0.58.5 remote-as 5
neighbor 8.0.68.6 remote-as 67
neighbor 8.0.78.7 remote-as 67
This is a basic iBGP and eBGP setup, which will use a as base for the next group of tasks.
Note that IOS-XR requires an explicit in and out route-policy for eBGP peerings.
In AS12, eBGP next-hop need to be reachable for routers R2 and R4. This can be achieved by either advertising external interfaces into IGP, or using next-hop-self on iBGP peerings. The recommended method, for the fast convergence, is to advertise eBGP next-hop into IGP. External interfaces are configured as passive in OSPF. Same solution shall be implemented in AS67.
Requirement #5 - since using network command is not allowed, use redistribution of static route into BGP.
R1:
!
interface Ethernet0/0
ip address 12.0.20.1 255.255.255.0
ip ospf 1 area 0
!
interface Ethernet1/0
ip address 5.0.15.1 255.255.255.0
ip ospf 1 area 0
!
router bgp 12
bgp log-neighbor-changes
neighbor 5.0.15.5 remote-as 5
neighbor 12.0.2.2 remote-as 12
neighbor 12.0.2.2 update-source Loopback0
neighbor 12.0.3.3 remote-as 12
neighbor 12.0.3.3 update-source Loopback0
neighbor 12.0.4.4 remote-as 12
neighbor 12.0.4.4 update-source Loopback0
!
router ospf 1
router-id 12.0.1.1
passive-interface Ethernet1/0
!
R2:
!router bgp 12
bgp log-neighbor-changes
network 12.0.0.0 mask 255.255.0.0
neighbor 12.0.1.1 remote-as 12
neighbor 12.0.1.1 update-source Loopback0
neighbor 12.0.3.3 remote-as 12
neighbor 12.0.3.3 update-source Loopback0
neighbor 12.0.4.4 remote-as 12
neighbor 12.0.4.4 update-source Loopback0
!
R3:
!
router ospf CCIE
router-id 12.0.3.3
area 0
interface Loopback0
!
interface GigabitEthernet0/0/0/0
passive enable
!
interface GigabitEthernet0/0/0/1
passive enable
!
interface GigabitEthernet0/0/0/2
!
!
!
router bgp 12
address-family ipv4 unicast
!
neighbor 12.0.1.1
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.2.2
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.4.4
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 67.0.36.6
remote-as 67
address-family ipv4 unicast
route-policy BGP_ALL in
route-policy BGP_ALL out
!
!
neighbor 67.0.37.7
remote-as 67
address-family ipv4 unicast
route-policy BGP_ALL in
route-policy BGP_ALL out
!
!
!
route-policy BGP_ALL
pass
end-policy
!
R4:
!router bgp 12
address-family ipv4 unicast
network 12.0.0.0/16
!
neighbor 12.0.1.1
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.2.2
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
neighbor 12.0.3.3
remote-as 12
update-source Loopback0
address-family ipv4 unicast
!
!
!
R5:
!
router bgp 5
bgp log-neighbor-changes
network 5.0.0.0 mask 255.255.0.0
neighbor 5.0.15.1 remote-as 12
neighbor 8.0.58.8 remote-as 8
!
R6:
!
interface Ethernet0/0
ip address 67.0.67.6 255.255.255.0
ip router isis CCIE
!
interface Ethernet1/0
ip address 67.0.36.6 255.255.255.0
!
interface Ethernet1/1
ip address 8.0.68.6 255.255.255.0
!
router isis CCIE
net 49.0067.0000.0000.0006.00
passive-interface Ethernet1/0
passive-interface Ethernet1/1
!
router bgp 67
bgp log-neighbor-changes
network 67.0.0.0 mask 255.255.0.0
neighbor 8.0.68.8 remote-as 8
neighbor 67.0.36.3 remote-as 12
neighbor 67.0.67.7 remote-as 67
!
R7:
!
interface Ethernet0/0
ip address 67.0.67.7 255.255.255.0
ip router isis CCIE
!
interface Ethernet1/0
ip address 67.0.37.7 255.255.255.0
!
interface Ethernet1/1
ip address 8.0.78.7 255.255.255.0
!
router isis CCIE
net 49.0067.0000.0000.0007.00
passive-interface Ethernet1/0
passive-interface Ethernet1/1
!
router bgp 67
bgp log-neighbor-changes
network 67.0.0.0 mask 255.255.0.0
neighbor 8.0.78.8 remote-as 8
neighbor 67.0.37.3 remote-as 12
neighbor 67.0.67.6 remote-as 67
!
R8:
!
router bgp 8
bgp log-neighbor-changes
redistribute static route-map STATIC
neighbor 8.0.58.5 remote-as 5
neighbor 8.0.68.6 remote-as 67
neighbor 8.0.78.7 remote-as 67
!
Verification:
R8#show bgp
BGP table version is 7, local router ID is 8.0.8.8
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*> 5.0.0.0/16 8.0.58.5 0 0 5 i
*> 8.0.0.0/16 0.0.0.0 0 32768 ?
* 12.0.0.0/16 8.0.78.7 0 67 12 i
* 8.0.68.6 0 67 12 i
*> 8.0.58.5 0 5 12 i
* 67.0.0.0/16 8.0.68.6 0 0 67 i
*> 8.0.78.7 0 0 67 i
RP/0/0/CPU0:R4#show bgp
Sun Dec 20 22:19:03.957 UTC
BGP router identifier 12.0.4.4, local AS number 12
BGP generic scan interval 60 secs
BGP table state: Active
Table ID: 0xe0000000 RD version: 9
BGP main routing table version 9
BGP scan interval 60 secs
Status codes: s suppressed, d damped, h history, * valid, > best
i - internal, r RIB-failure, S stale, N Nexthop-discard
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
*>i5.0.0.0/16 5.0.15.5 0 100 0 5 i
*>i8.0.0.0/16 5.0.15.5 0 100 0 5 8 ?
* i 67.0.36.6 100 0 67 8 ?
*> 12.0.0.0/16 0.0.0.0 0 32768 i
* i 12.0.2.2 0 100 0 i
*>i67.0.0.0/16 67.0.36.6 0 100 0 67 i
Processed 4 prefixes, 6 paths
R2#show bgp
BGP table version is 9, local router ID is 12.0.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter,
x best-external, a additional-path, c RIB-compressed,
Origin codes: i - IGP, e - EGP, ? - incomplete
RPKI validation codes: V valid, I invalid, N Not found
Network Next Hop Metric LocPrf Weight Path
*>i 5.0.0.0/16 5.0.15.5 0 100 0 5 i
* i 8.0.0.0/16 67.0.36.6 100 0 67 8 ?
*>i 5.0.15.5 0 100 0 5 8 ?
* i 12.0.0.0/16 12.0.4.4 0 100 0 i
*> 0.0.0.0 0 32768 i
*>i 67.0.0.0/16 67.0.36.6 0 100 0 67 i
