GRE TUNNEL Configurations

********************CONFIGURATIONS*****************************

CE1 configurations:

BGP Configurations:

CE1#sh run | sec bgp
ipv6 multicast rpf use-bgp
router bgp 100
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255
neighbor 192.168.12.2 remote-as 65512

CE2 configurations:

BGP Configurations:

CE2#sh run | sec bgp
ipv6 multicast rpf use-bgp
router bgp 500
bgp log-neighbor-changes
network 5.5.5.5 mask 255.255.255.255
neighbor 192.168.45.4 remote-as 65512

PE1 router configurations:

BGP Configurations:

PE1#sh run | sec bgp
ipv6 multicast rpf use-bgp
router bgp 65512
bgp log-neighbor-changes
neighbor 192.168.12.1 remote-as 100
neighbor 192.168.24.4 remote-as 65512
neighbor 192.168.24.4 next-hop-self

OSPF Configurations:

PE1#sh run | sec ospf
router ospf 1
network 2.2.2.2 0.0.0.0 area 0
network 192.168.23.0 0.0.0.255 area 0

GRE Tunnel Configurations:

PE1#show run int tun0
Building configuration…

Current configuration : 115 bytes
!
interface Tunnel0
ip address 192.168.24.2 255.255.255.0
tunnel source 2.2.2.2
tunnel destination 4.4.4.4
end

PE2 Configurations:

BGP Configurations:

PE2#sh run | sec bgp
ipv6 multicast rpf use-bgp
router bgp 65512
bgp log-neighbor-changes
neighbor 192.168.24.2 remote-as 65512
neighbor 192.168.24.2 next-hop-self
neighbor 192.168.45.5 remote-as 500

OSPF Configurations:

PE2#show run | sec ospf
router ospf 1
network 4.4.4.4 0.0.0.0 area 0
network 192.168.34.0 0.0.0.255 area 0

GRE Tunnel Configurations:

PE2#show run int tunnel 0
Building configuration…

Current configuration : 115 bytes
!
interface Tunnel0
ip address 192.168.24.4 255.255.255.0
tunnel source 4.4.4.4
tunnel destination 2.2.2.2
end

P Router Configurations:

OSPF Configurations:

P#show run | sec ospf
router ospf 1
network 3.3.3.3 0.0.0.0 area 0
network 192.168.23.0 0.0.0.255 area 0
network 192.168.34.0 0.0.0.255 area 0

*********************VERIFICATIONS**************************************

a. BGP neighbors:

CE1#show ip bgp summary
BGP router identifier 1.1.1.1, local AS number 100
BGP table version is 1, main routing table version 1

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
192.168.12.2 4 65512 48 48 1 0 0 00:40:27 0
CE1#

CE2#show ip bgp summary
BGP router identifier 5.5.5.5, local AS number 500
BGP table version is 1, main routing table version 1

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
192.168.45.4 4 65512 40 40 1 0 0 00:33:18 0
CE2#

PE1#show ip bgp summary
BGP router identifier 2.2.2.2, local AS number 65512
BGP table version is 1, main routing table version 1
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
192.168.12.1 4 100 53 53 1 0 0 00:44:47 0
192.168.24.4 4 65512 34 34 1 0 0 00:27:57 0

PE2#show ip bgp summary

BGP router identifier 4.4.4.4, local AS number 65512

BGP table version is 1, main routing table version 1

Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd

192.168.24.2 4 65512 42 42 1 0 0 00:35:10 0

192.168.45.5 4 500 50 50 1 0 0 00:42:28 0

PE2#

b. OSPF Neighbors:

PE1#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
3.3.3.3 0 FULL/ – 00:00:32 192.168.23.3 Serial3/1
PE1#

PE2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

3.3.3.3 0 FULL/ – 00:00:38 192.168.34.3 Serial3/2

P#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface
4.4.4.4 0 FULL/ – 00:00:33 192.168.34.4 Serial3/2
2.2.2.2 0 FULL/ – 00:00:34 192.168.23.2 Serial3/1
P#

c. Routing table in CE1:

CE1#show ip route
Codes: L – local, 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, H – NHRP, l – LISP
+ – replicated route, % – next hop override

Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
5.0.0.0/32 is subnetted, 1 subnets
B 5.5.5.5 [20/0] via 192.168.12.2, 00:00:36
192.168.12.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.12.0/24 is directly connected, Serial3/0
L 192.168.12.1/32 is directly connected, Serial3/0

d. Routing table in CE2:

CE2#show ip route

Codes: L – local, 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, H – NHRP, l – LISP

+ – replicated route, % – next hop override

Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets

B 1.1.1.1 [20/0] via 192.168.45.4, 00:01:50

5.0.0.0/32 is subnetted, 1 subnets

C 5.5.5.5 is directly connected, Loopback0

192.168.45.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.45.0/24 is directly connected, Serial3/0

L 192.168.45.5/32 is directly connected, Serial3/0

e. Testing for reachability between CE1 and CE2 loopback inteface:

CE1#traceroute 5.5.5.5 source loopback 0
Type escape sequence to abort.
Tracing the route to 5.5.5.5
VRF info: (vrf in name/id, vrf out name/id)
1 192.168.12.2 44 msec 32 msec 8 msec
2 192.168.24.4 40 msec 8 msec 32 msec
3 192.168.45.5 88 msec 44 msec 48 msec

CE2#ping 1.1.1.1 source 5.5.5.5

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 1.1.1.1, timeout is 2 seconds:

Packet sent with a source address of 5.5.5.5

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 80/106/172 ms

*********************END *****************************************

NETWORK LESSON