Huawei equipment is configured to access the virtual private network through GRE

1. To configure IP Address
   [CE1-GigabitEthernet0/0/0]ip add 20.1.1.1 24
   [CE1-GigabitEthernet0/0/1]ip add 10.1.1.1 24
   [AR2-GigabitEthernet0/0/0]ip add 20.1.1.2 24
   [AR2-GigabitEthernet0/0/1]ip add 30.1.1.2 24
   [PE1-GigabitEthernet0/0/0]ip add 30.1.1.3 24
   [PE1-GigabitEthernet0/0/1]ip add 40.1.1.3 24
   [PE1-LoopBack0]ip add 3.3.3.3 32
   [PE2-GigabitEthernet0/0/0]ip add 40.1.1.4 24
   [PE2-GigabitEthernet0/0/1]ip add 11.1.1.4 24
   [PE2-LoopBack0]ip add 4.4.4.4 32
   [CE2-GigabitEthernet0/0/0]ip add 11.1.1.5 24
   [CE2-GigabitEthernet0/0/1]ip add 10.2.1.5 24
   
   

2. To configure PE Routing and MPLS
   [PE1]mpls lsr-id 3.3.3.3
   [PE1]mpls
   [PE1-mpls]lsp-trigger all
   [PE1]mpls ldp
   [PE1]ospf 1
   [PE1-ospf-1]area 0
   [PE1-ospf-1-area-0.0.0.0]network 3.3.3.3 0.0.0.0
   [PE1-ospf-1-area-0.0.0.0]network 40.1.1.0 0.0.0.255
   [PE1-GigabitEthernet0/0/1]mpls
   [PE1-GigabitEthernet0/0/1]mpls ldp
   [PE2]mpls lsr-id 4.4.4.4
   [PE2]mpls
   [PE2-mpls]lsp-trigger all
   [PE2]mpls ldp
   [PE2]ospf 1
   [PE2-ospf-1]area 0
   [PE2-ospf-1-area-0.0.0.0]network 4.4.4.4 0.0.0.0
   [PE2-ospf-1-area-0.0.0.0]network 40.1.1.0 0.0.0.255
   [PE2-GigabitEthernet0/0/0]mpls
   [PE2-GigabitEthernet0/0/0]mpls ldp

3. stay PE1 establish VPN example vpn1 And with GRE Tunnel binding
   [PE1]ip vpn-instance vpn1
   [PE1-vpn-instance-vpn1]route-distinguisher 100:1
   [PE1-vpn-instance-vpn1-af-ipv4]vpn-target 111:1 export-extcommunity
   [PE1-vpn-instance-vpn1-af-ipv4]vpn-target 111:1 import-extcommunity
   [PE1]int Tunnel 0/0/1
   [PE1-Tunnel0/0/1]ip binding vpn-instance vpn1
   [PE1-Tunnel0/0/1]ip add 2.2.2.3 24

4. stay PE2 establish VPN example vpn1 And with PC Side interface binding
   [PE2]ip vpn-instance vpn1
   [PE2-vpn-instance-vpn1]route-distinguisher 200:1
   [PE2-vpn-instance-vpn1-af-ipv4]vpn-target 111:1 export-extcommunity
   [PE2-vpn-instance-vpn1-af-ipv4]vpn-target 111:1 import-extcommunity
   [PE2-GigabitEthernet0/0/1]ip binding vpn-instance vpn1
   [PE2-GigabitEthernet0/0/1]ip add 11.1.1.4 24

5. To configure GRE Of the tunnel Tunnel Interface
   [CE1]int Tunnel 0/0/1
   [CE1-Tunnel0/0/1]tunnel-protocol gre
   [CE1-Tunnel0/0/1]source 20.1.1.1
   [CE1-Tunnel0/0/1]destination 30.1.1.3
   [CE1-Tunnel0/0/1]ip add 2.2.2.1 24
   [PE1]int Tunnel 0/0/1
   [PE1-Tunnel0/0/1]tunnel-protocol gre
   [PE1-Tunnel0/0/1]source 30.1.1.3
   [PE1-Tunnel0/0/1]destination 20.1.1.1

6. To configure CE1、AR2 and PE1 Routing protocol between
   [CE1]ospf 2
   [CE1-ospf-2]area 0
   [CE1-ospf-2-area-0.0.0.0]network 20.1.1.0 0.0.0.255
   [AR2]ospf 2
   [AR2-ospf-2]area 0
   [AR2-ospf-2-area-0.0.0.0]network 20.1.1.0 0.0.0.255
   [AR2-ospf-2-area-0.0.0.0]network 30.1.1.0 0.0.0.255
   [PE1]ospf 2
   [PE1-ospf-2]area 0
   [PE1-ospf-2-area-0.0.0.0]network 30.1.1.0 0.0.0.255

7. To configure CE1 And PE1 Between IS-IS route
   [CE1]isis 20
   [CE1-isis-20]network-entity 20.0000.0000.0001.00
   [CE1-GigabitEthernet0/0/0]isis enable 20
   [CE1-Tunnel0/0/1]isis enable 20
   [PE1]isis 20 vpn-instance vpn1
   [PE1-isis-20]network-entity 20.0000.0000.0003.00
   [PE1]int Tunnel 0/0/1
   [PE1-Tunnel0/0/1]isis enable 20

8. To configure CE2 And PE2 Between IS-IS route
   [CE2]isis 20
   [CE2-isis-20]network-entity 20.0000.0000.0005.00
   [CE2-GigabitEthernet0/0/0]isis enable 20
   [CE2-GigabitEthernet0/0/1]isis enable 20
   [PE2]isis 20 vpn-instance vpn1
   [PE2-isis-20]network-entity 20.0000.0000.0004.00
   [PE2-GigabitEthernet0/0/1]isis enable 20

9. stay PE Establish between MP-IBGP peers
   [PE1]bgp 100
   [PE1-bgp]peer 4.4.4.4 as-number 100
   [PE1-bgp]peer 4.4.4.4 connect-interface LoopBack 0
   [PE1-bgp]ipv4-family vpnv4
   [PE1-bgp-af-vpnv4]peer 4.4.4.4 enable
   [PE1-bgp]ipv4-family vpn-instance vpn1 // Get into BGP Of vpn1 example
   [PE1-bgp-vpn1]import-route isis 20 // introduce IS-IS route
   [PE2]bgp 100
   [PE2-bgp]peer 3.3.3.3 as-number 100
   [PE2-bgp]peer 3.3.3.3 connect-interface LoopBack 0
   [PE2-bgp]ipv4-family vpnv4
   [PE2-bgp-af-vpnv4]peer 3.3.3.3 enable
   [PE2-bgp]ipv4-family vpnv4
   [PE2-bgp]ipv4-family vpn-instance vpn1
   [PE2-bgp-vpn1]import-route isis 20

10. stay IS-IS Introduction in BGP route
    [PE1]isis 20
    [PE1-isis-20]import-route bgp
    [PE2]isis 20
    [PE2-isis-20]import-route bgp

11. Check the configuration