Example for Configuring an OSPF Sham Link
This section provides an example for configuring an OSPF sham link so that traffic between sites of the same VPN in the same OSPF area is forwarded through the OSPF intra-area route over the BGP/MPLS IP VPN backbone network.
Networking Requirements
In Figure 1, CE1 and CE2 reside in the same OSPF area, belong to VPN1, and are connected to PE1 and PE2, respectively. In this example, the cost of each link is 1.
It is required that OSPF run between each CE and its connected PE and the VPN traffic between CE1 and CE2 be forwarded over the MPLS backbone network.
Configuration Roadmap
The configuration roadmap is as follows:
Configure an MP-IBGP peer relationship between PEs and configure OSPF between each CE and its connected PE.
Create a VPN instance on each PE and bind the VPN instance to the interface connected to the corresponding CE.
Create an OSPF sham link between PEs.
Adjust the cost of forwarding interfaces over the user network to ensure that the cost of the OSPF route used to forward the traffic over the user network is greater than that of the sham link.
Data Preparation
To complete the configuration, you need the following data:
MPLS LSR IDs of the PEs and P
VPN instance name, RD, and VPN target of each PE
Data used to configure OSPF (The OSPF process running on the backbone network, the OSPF process running on the user network, and the OSPF process connecting each PE to the corresponding CE are different.)
Cost of the sham link and the cost of the OSPF route used to forward the traffic over the user network
Procedure
- Configure OSPF on the user network.
Configure OSPF on CE1, RT0, and CE2 and advertise network segments of their interfaces.
# Configure CE1.
<HUAWEI> system-view [~HUAWEI] sysname CE1 [~CE1] interface GigabitEthernet0/1/8 [~CE1-GigabitEthernet0/1/8] ip address 10.1.1.1 24 [*CE1-GigabitEthernet0/1/8] quit [*CE1] interface GigabitEthernet0/1/0 [*CE1-GigabitEthernet0/1/0] ip address 172.16.1.1 24 [*CE1-GigabitEthernet0/1/0] quit [*CE1] ospf [*CE1-ospf-1] area 0 [*CE1-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255 [*CE1-ospf-1-area-0.0.0.0] network 172.16.1.0 0.0.0.255 [*CE1-ospf-1-area-0.0.0.0] quit [*CE1-ospf-1] quit [*CE1] commit
# Configure RT0.
<HUAWEI> system-view [~HUAWEI] sysname RT0 [~RT0] interface GigabitEthernet0/1/0 [~RT0-GigabitEthernet0/1/0] ip address 10.1.1.2 24 [*RT0-GigabitEthernet0/1/0] quit [*RT0] interface GigabitEthernet0/1/8 [*RT0-GigabitEthernet0/1/8] ip address 10.2.1.1 24 [*RT0-GigabitEthernet0/1/8] quit [*RT0] ospf [*RT0-ospf-1] area 0 [*RT0-ospf-1-area-0.0.0.0] network 10.1.1.0 0.0.0.255 [*RT0-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255 [*RT0-ospf-1-area-0.0.0.0] quit [*RT0-ospf-1] quit [*RT0] commit
# Configure CE2.
<HUAWEI> system-view [~HUAWEI] sysname CE2 [~CE2] interface GigabitEthernet0/1/8 [~CE2-GigabitEthernet0/1/8] ip address 10.2.1.2 24 [*CE2-GigabitEthernet0/1/8] quit [*CE2] interface GigabitEthernet0/1/0 [*CE2-GigabitEthernet0/1/0] ip address 172.16.2.1 24 [*CE2-GigabitEthernet0/1/0] quit [*CE2] ospf [*CE2-ospf-1] area 0 [*CE2-ospf-1-area-0.0.0.0] network 10.2.1.0 0.0.0.255 [*CE2-ospf-1-area-0.0.0.0] network 172.16.2.0 0.0.0.255 [*CE2-ospf-1-area-0.0.0.0] quit [*CE2-ospf-1] quit [*CE2] commit
- Configure basic BGP/MPLS IP VPN functions on the backbone network, including an IGP (OSPF) on the backbone network, MPLS and LDP on the backbone network, and an MP-IBGP peer relationship between PEs.
# Configure PE1.
<HUAWEI> system-view [~HUAWEI] sysname PE1 [~PE1] interface loopback 1 [~PE1-LoopBack1] ip address 1.1.1.9 32 [*PE1-LoopBack1] quit [*PE1] mpls lsr-id 1.1.1.9 [*PE1] mpls [*PE1-mpls] quit [*PE1] mpls ldp [*PE1-mpls-ldp] quit [*PE1] interface GigabitEthernet0/1/8 [*PE1-GigabitEthernet0/1/8] ip address 10.10.1.1 24 [*PE1-GigabitEthernet0/1/8] mpls [*PE1-GigabitEthernet0/1/8] mpls ldp [*PE1-GigabitEthernet0/1/8] quit [*PE1] ospf [*PE1-ospf-1] area 0 [*PE1-ospf-1-area-0.0.0.0] network 1.1.1.9 0.0.0.0 [*PE1-ospf-1-area-0.0.0.0] network 10.10.1.0 0.0.0.255 [*PE1-ospf-1-area-0.0.0.0] quit [*PE1-ospf-1] quit [*PE1] bgp 100 [*PE1-bgp] peer 3.3.3.9 as-number 100 [*PE1-bgp] peer 3.3.3.9 connect-interface loopback 1 [*PE1-bgp] ipv4-family vpnv4 [*PE1-bgp-af-vpnv4] peer 3.3.3.9 enable [*PE1-bgp-af-vpnv4] quit [*PE1-bgp] quit [*PE1] commit
# Configure the P.
<HUAWEI> system-view [~HUAWEI] sysname P [~P] interface loopback 1 [~P-LoopBack1] ip address 2.2.2.9 32 [*P-LoopBack1] quit [*P] mpls lsr-id 2.2.2.9 [*P] mpls [*P-mpls] quit [*P] mpls ldp [*P-mpls-ldp] quit [*P] interface GigabitEthernet0/1/0 [*P-GigabitEthernet0/1/0] ip address 10.10.1.2 24 [*P-GigabitEthernet0/1/0] mpls [*P-GigabitEthernet0/1/0] mpls ldp [*P-GigabitEthernet0/1/0] quit [*P] interface GigabitEthernet0/1/8 [*P-GigabitEthernet0/1/8] ip address 10.20.1.1 24 [*P-GigabitEthernet0/1/8] mpls [*P-GigabitEthernet0/1/8] mpls ldp [*P-GigabitEthernet0/1/8] quit [*P] ospf [*P-ospf-1] area 0 [*P-ospf-1-area-0.0.0.0] network 2.2.2.9 0.0.0.0 [*P-ospf-1-area-0.0.0.0] network 10.10.1.0 0.0.0.255 [*P-ospf-1-area-0.0.0.0] network 10.20.1.0 0.0.0.255 [*P-ospf-1-area-0.0.0.0] quit [*P-ospf-1] quit [*P] commit
# Configure PE2.
<HUAWEI> system-view [~HUAWEI] sysname PE2 [~PE2] interface loopback 1 [~PE2-LoopBack1] ip address 3.3.3.9 32 [*PE2-LoopBack1] quit [*PE2] mpls lsr-id 3.3.3.9 [*PE2] mpls [*PE2-mpls] quit [*PE2] mpls ldp [*PE2-mpls-ldp] quit [*PE2] interface GigabitEthernet0/1/8 [*PE2-GigabitEthernet0/1/8] ip address 10.20.1.2 24 [*PE2-GigabitEthernet0/1/8] mpls [*PE2-GigabitEthernet0/1/8] mpls ldp [*PE2-GigabitEthernet0/1/8] quit [*PE2] ospf [*PE2-ospf-1] area 0 [*PE2-ospf-1-area-0.0.0.0] network 3.3.3.9 0.0.0.0 [*PE2-ospf-1-area-0.0.0.0] network 10.20.1.0 0.0.0.255 [*PE2-ospf-1-area-0.0.0.0] quit [*PE2-ospf-1] quit [*PE2] bgp 100 [*PE2-bgp] peer 1.1.1.9 as-number 100 [*PE2-bgp] peer 1.1.1.9 connect-interface loopback 1 [*PE2-bgp] ipv4-family vpnv4 [*PE2-bgp-af-vpnv4] peer 1.1.1.9 enable [*PE2-bgp-af-vpnv4] quit [*PE2-bgp] quit [*PE2] commit
After completing the configurations, PE1 and PE2 learn the route to each other's loopback interface and establish an MP-IBGP peer relationship.
- Configure the connection between each PE and the corresponding CE, with OSPF running between them.
# Configure PE1.
[~PE1] ip vpn-instance vpn1 [*PE1-vpn-instance-vpn1] ipv4-family [*PE1-vpn-instance-vpn1-af-ipv4] route-distinguisher 100:1 [*PE1-vpn-instance-vpn1-af-ipv4] vpn-target 1:1 [*PE1-vpn-instance-vpn1-af-ipv4] quit [*PE1-vpn-instance-vpn1] quit [*PE1] interface gigabitethernet 0/1/0 [*PE1-GigabitEthernet0/1/0] ip binding vpn-instance vpn1 [*PE1-GigabitEthernet0/1/0] ip address 172.16.1.2 24 [*PE1-GigabitEthernet0/1/0] quit [*PE1] ospf 100 vpn-instance vpn1 [*PE1-ospf-100] domain-id 10 [*PE1-ospf-100] import-route bgp [*PE1-ospf-100] area 0 [*PE1-ospf-100-area-0.0.0.0] network 172.16.1.0 0.0.0.255 [*PE1-ospf-100-area-0.0.0.0] quit [*PE1-ospf-100] quit [*PE1] bgp 100 [*PE1-bgp] ipv4-family vpn-instance vpn1 [*PE1-bgp-vpn1] import-route direct [*PE1-bgp-vpn1] import-route ospf 100 [*PE1-bgp-vpn1] quit [*PE1-bgp] quit [*PE1] commit
# Configure PE2.
[~PE2] ip vpn-instance vpn1 [*PE2-vpn-instance-vpn1] ipv4-family [*PE2-vpn-instance-vpn1-af-ipv4] route-distinguisher 100:2 [*PE2-vpn-instance-vpn1-af-ipv4] vpn-target 1:1 [*PE2-vpn-instance-vpn1-af-ipv4] quit [*PE2-vpn-instance-vpn1] quit [*PE2] interface GigabitEthernet0/1/0 [*PE2-GigabitEthernet0/1/0] ip binding vpn-instance vpn1 [*PE2-GigabitEthernet0/1/0] ip address 172.16.2.2 24 [*PE2-GigabitEthernet0/1/0] quit [*PE2] ospf 100 vpn-instance vpn1 [*PE2-ospf-100] import-route bgp [*PE2-ospf-100] domain-id 10 [*PE2-ospf-100] area 0 [*PE2-ospf-100-area-0.0.0.0] network 172.16.2.0 0.0.0.255 [*PE2-ospf-100-area-0.0.0.0] quit [*PE2-ospf-100] quit [*PE2] bgp 100 [*PE2-bgp] ipv4-family vpn-instance vpn1 [*PE2-bgp-vpn1] import-route direct [*PE2-bgp-vpn1] import-route ospf 100 [*PE2-bgp-vpn1] quit [*PE2-bgp] quit [*PE2] commit
After completing the configurations, run the display ip routing-table vpn-instance command on a PE. You may find that the route to the remote CE is an OSPF route over the user network rather than the BGP route over the backbone network.
The following example uses the command output on PE1.
<PE1> display ip routing-table vpn-instance vpn1 Route Flags: R - relay, D - download to fib, T - to vpn-instance, B - black hole route ------------------------------------------------------------------------------ Routing Table: vpn1 Destinations : 5 Routes : 5 Destination/Mask Proto Pre Cost Flags NextHop Interface 10.1.1.0/24 OSPF 10 2 D 172.16.1.1 GigabitEthernet0/1/0 10.2.1.0/24 OSPF 10 3 D 172.16.1.1 GigabitEthernet0/1/0 172.16.1.0/24 Direct 0 0 D 172.16.1.2 GigabitEthernet0/1/0 172.16.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/1/0 172.16.2.0/24 OSPF 10 4 D 172.16.1.1 GigabitEthernet0/1/0
- Configure a sham link.
To ensure that VPN traffic is forwarded over the MPLS backbone network, ensure that the cost of the sham link is smaller than that of the OSPF route used to forward the traffic over the user network when configuring the sham link. In most cases, you need to change the cost of the interfaces on the user network to ensure that the cost of the OSPF route used to forward the traffic over the user network is greater than that of the sham link.
# Configure CE1.
[~CE1] interface GigabitEthernet0/1/8 [~CE1-GigabitEthernet0/1/8] ospf cost 10
# Configure CE2.
[~CE2] interface GigabitEthernet0/1/8 [~CE2-GigabitEthernet0/1/8] ospf cost 10 [~CE2] interface loopback 1 [~CE2-LoopBack1] ip address 8.8.8.8 32 [*CE2-LoopBack1] ospf enable 1 area 0 [*CE2-LoopBack1] quit [*CE2] commit
# Configure PE1.
[~PE1] interface loopback 10 [*PE1-LoopBack10] ip binding vpn-instance vpn1 [*PE1-LoopBack10] ip address 5.5.5.5 32 [*PE1-LoopBack10] quit [*PE1] ospf 100 router-id 11.11.11.11 [*PE1-ospf-100] area 0 [*PE1-ospf-100-area-0.0.0.0] sham-link 5.5.5.5 6.6.6.6 cost 1 [*PE1-ospf-100-area-0.0.0.0] quit [*PE1-ospf-100] quit [*PE1] commit
# Configure PE2.
[~PE2] interface loopback 10 [*PE2-LoopBack10] ip binding vpn-instance vpn1 [*PE2-LoopBack10] ip address 6.6.6.6 32 [*PE2-LoopBack10] quit [*PE2] ospf 100 router-id 22.22.22.22 [*PE2-ospf-100] area 0 [*PE2-ospf-100-area-0.0.0.0] sham-link 6.6.6.6 5.5.5.5 cost 1 [*PE2-ospf-100-area-0.0.0.0] quit [*PE2-ospf-100] quit [*PE2] commit
- Verify the configuration.
After completing the configurations, run the display ip routing-table vpn-instance command again on the PE. You may find that the route to the remote CE becomes the BGP route over the backbone network and a route to the destination IP address of the sham link also exist in the routing table.
The following example uses the command output on PE1.
<PE1> display ip routing-table vpn-instance vpn1 Route Flags: R - relay, D - download to fib, T - to vpn-instance, B - black hole route ------------------------------------------------------------------------------ Routing Table: vpn1 Destinations : 10 Routes : 10 Destination/Mask Proto Pre Cost Flags NextHop Interface 5.5.5.5/32 Direct 0 0 D 127.0.0.1 LoopBack10 6.6.6.6/32 IBGP 255 0 RD 3.3.3.9 GigabitEthernet0/1/8 8.8.8.8/32 IBGP 255 2 RD 3.3.3.9 GigabitEthernet0/1/8 10.1.1.0/24 OSPF 10 11 D 172.16.1.1 GigabitEthernet0/1/0 10.2.1.0/24 OSPF 10 12 D 172.16.1.1 GigabitEthernet0/1/0 172.16.1.0/24 Direct 0 0 D 172.16.1.2 GigabitEthernet0/1/0 172.16.1.2/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/1/0 172.16.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/1/0 172.16.2.0/24 IBGP 255 0 RD 3.3.3.9 GigabitEthernet0/1/8 255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
Run the display ip routing-table command on a CE. You may find that the cost of the OSPF route to the remote CE becomes 3 and the next hop is the IP address of the connected PE interface. The next hop indicates that the VPN traffic to the remote end is forwarded over the backbone network.
The following example uses the command output on CE1.
<CE1> display ip routing-table Route Flags: R - relay, D - download to fib, T - to vpn-instance, B - black hole route ------------------------------------------------------------------------------ Routing Table : _public_ Destinations : 15 Routes : 15 Destination/Mask Proto Pre Cost Flags NextHop Interface 5.5.5.5/32 O_ASE 150 1 D 172.16.1.2 GigabitEthernet0/1/0 6.6.6.6/32 O_ASE 150 1 D 172.16.1.2 GigabitEthernet0/1/0 8.8.8.8/32 OSPF 10 3 D 172.16.1.2 GigabitEthernet0/1/0 10.1.1.0/24 Direct 0 0 D 10.1.1.1 GigabitEthernet0/1/8 10.1.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/1/8 10.1.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/1/8 10.2.1.0/24 OSPF 10 11 D 10.1.1.2 GigabitEthernet0/1/8 127.0.0.0/8 Direct 0 0 D 127.0.0.1 InLoopBack0 127.0.0.1/32 Direct 0 0 D 127.0.0.1 InLoopBack0 127.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0 172.16.1.0/24 Direct 0 0 D 172.16.1.1 GigabitEthernet0/1/0 172.16.1.1/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/1/0 172.16.1.255/32 Direct 0 0 D 127.0.0.1 GigabitEthernet0/1/0 172.16.2.0/24 OSPF 10 3 D 172.16.1.2 GigabitEthernet0/1/0 255.255.255.255/32 Direct 0 0 D 127.0.0.1 InLoopBack0
Cost (3) of the OSPF route from CE1 to CE2 = Cost (1) of the link from CE1 to PE1 + Cost (1) of the sham link + Cost (1) of the link from PE2 to CE2
Run the tracert command and you may find that the next hop for CE1 to send data to CE2 is the IP address of PE1's GE 0/1/0. The next hop indicates that the VPN traffic to the remote end is forwarded over the backbone network.
<CE1> tracert 172.16.2.1 traceroute to 172.16.2.1(172.16.2.1), max hops: 30 ,packet length: 40,press CTRL_C to break 1 172.16.1.2 131 ms 2 ms 1 ms 2 10.10.1.2 475 ms 4 ms 4 ms 3 172.16.2.2 150 ms 3 ms 4 ms 4 172.16.2.1 76 ms 3 ms 5 ms <CE1> tracert 10.2.1.2 traceroute to 10.2.1.2(10.2.1.2), max hops: 30 ,packet length: 40,press CTRL_C to break 1 10.1.1.2 60 ms 1 ms 1 ms 2 10.2.1.2 12 ms 2 ms 2 ms
Run the display ospf sham-link command on a PE to check whether the sham link is established.
The following example uses the command output on PE1.
<PE1> display ospf sham-link OSPF Process 100 with Router ID 11.11.11.11 Area NeighborId Source-IP Destination-IP State Cost 0.0.0.0 22.22.22.22 5.5.5.5 6.6.6.6 P-2-P 1Run the display ospf sham-link area command. The following command output shows that the OSPF neighbor relationship is in Full state.
<PE1> display ospf sham-link area 0 OSPF Process 100 with Router ID 11.11.11.11 Sham-Link: 5.5.5.5 --> 6.6.6.6 NeighborID: 22.22.22.22, State: Full, GR status: Normal Area: 0.0.0.0 Cost: 1 , State: P-2-P , Type: Sham Timers: Hello 10 , Dead 40 , Retransmit 5 , Transmit Delay 1Run the display ospf routing command on a CE. The following command output shows that the route to the remote CE is an intra-area route.
<CE1> display ospf routing OSPF Process 1 with Router ID 10.1.1.1 Routing Tables Routing for Network Destination Cost Type NextHop AdvRouter Area 8.8.8.8/32 3 Stub 172.16.1.2 10.2.1.2 0.0.0.0 10.1.1.0/24 10 Direct 10.1.1.1 10.1.1.1 0.0.0.0 10.2.1.0/24 11 Transit 10.1.1.2 10.1.1.2 0.0.0.0 172.16.1.0/24 1 Direct 172.16.1.1 10.1.1.1 0.0.0.0 172.16.2.0/24 3 Transit 172.16.1.2 10.2.1.2 0.0.0.0 Routing for ASEs Destination Cost Type Tag NextHop AdvRouter 6.6.6.6/32 1 Type2 3489661028 172.16.1.2 11.11.11.11 5.5.5.5/32 1 Type2 3489661028 172.16.1.2 22.22.22.22 Total Nets: 7 Intra Area: 5 Inter Area: 0 ASE: 2 NSSA: 0
Configuration Files
PE1 configuration file
# sysname PE1 # ip vpn-instance vpn1 ipv4-family route-distinguisher 100:1 apply-label per-instance vpn-target 1:1 export-extcommunity vpn-target 1:1 import-extcommunity # mpls lsr-id 1.1.1.9 mpls # mpls ldp # interface GigabitEthernet0/1/0 undo shutdown ip binding vpn-instance vpn1 ip address 172.16.1.2 255.255.255.0 # interface GigabitEthernet0/1/8 undo shutdown ip address 10.10.1.1 255.255.255.0 mpls mpls ldp # interface LoopBack1 ip address 1.1.1.9 255.255.255.255 # interface LoopBack10 ip binding vpn-instance vpn1 ip address 5.5.5.5 255.255.255.255 # bgp 100 peer 3.3.3.9 as-number 100 peer 3.3.3.9 connect-interface LoopBack1 # ipv4-family unicast undo synchronization peer 3.3.3.9 enable # ipv4-family vpnv4 policy vpn-target peer 3.3.3.9 enable # ipv4-family vpn-instance vpn1 import-route direct import-route ospf 100 # ospf 1 area 0.0.0.0 network 1.1.1.9 0.0.0.0 network 10.10.1.0 0.0.0.255 # ospf 100 router-id 11.11.11.11 vpn-instance vpn1 import-route bgp domain-id 0.0.0.10 area 0.0.0.0 network 172.16.1.0 0.0.0.255 sham-link 5.5.5.5 6.6.6.6 cost 1 # return
P configuration file
# sysname P # mpls lsr-id 2.2.2.9 mpls # mpls ldp # interface GigabitEthernet0/1/0 undo shutdown ip address 10.10.1.2 255.255.255.0 mpls mpls ldp # interface GigabitEthernet0/1/8 undo shutdown ip address 10.20.1.1 255.255.255.0 mpls mpls ldp # interface LoopBack1 ip address 2.2.2.9 255.255.255.255 # ospf 1 area 0.0.0.0 network 2.2.2.9 0.0.0.0 network 10.10.1.0 0.0.0.255 network 10.20.1.0 0.0.0.255 # return
PE2 configuration file
# sysname PE2 # ip vpn-instance vpn1 ipv4-family route-distinguisher 100:2 apply-label per-instance vpn-target 1:1 export-extcommunity vpn-target 1:1 import-extcommunity # mpls lsr-id 3.3.3.9 mpls # mpls ldp # interface GigabitEthernet0/1/0 undo shutdown ip binding vpn-instance vpn1 ip address 172.16.2.2 255.255.255.0 # interface GigabitEthernet0/1/8 undo shutdown ip address 10.20.1.2 255.255.255.0 mpls mpls ldp # interface LoopBack1 ip address 3.3.3.9 255.255.255.255 # interface LoopBack10 ip binding vpn-instance vpn1 ip address 6.6.6.6 255.255.255.255 # bgp 100 peer 1.1.1.9 as-number 100 peer 1.1.1.9 connect-interface LoopBack1 # ipv4-family unicast undo synchronization peer 1.1.1.9 enable # ipv4-family vpnv4 policy vpn-target peer 1.1.1.9 enable # ipv4-family vpn-instance vpn1 import-route direct import-route ospf 100 # ospf 1 area 0.0.0.0 network 3.3.3.9 0.0.0.0 network 10.20.1.0 0.0.0.255 # ospf 100 router-id 22.22.22.22 vpn-instance vpn1 import-route bgp domain-id 0.0.0.10 area 0.0.0.0 network 172.16.2.0 0.0.0.255 sham-link 6.6.6.6 5.5.5.5 cost 1 # return
CE1 configuration file
# sysname CE1 # interface GigabitEthernet0/1/0 undo shutdown ip address 172.16.1.1 255.255.255.0 # interface GigabitEthernet0/1/8 undo shutdown ip address 10.1.1.1 255.255.255.0 ospf cost 10 # interface LoopBack0 ip address 8.8.8.8 255.255.255.255 ospf enable 1 area 0.0.0.0 # ospf 1 area 0.0.0.0 network 172.16.1.0 0.0.0.255 network 10.1.1.0 0.0.0.255 # return
CE2 configuration file
# sysname CE2 # interface GigabitEthernet0/1/0 undo shutdown ip address 172.16.2.1 255.255.255.0 # interface GigabitEthernet0/1/8 undo shutdown ip address 10.2.1.2 255.255.255.0 ospf cost 10 # ospf 1 area 0.0.0.0 network 10.2.1.0 0.0.0.255 network 172.16.2.0 0.0.0.255 # return
RT0 configuration file
# sysname RT0 # interface GigabitEthernet0/1/0 undo shutdown ip address 10.1.1.2 255.255.255.0 # interface GigabitEthernet0/1/8 undo shutdown ip address 10.2.1.1 255.255.255.0 # ospf 1 area 0.0.0.0 network 10.1.1.0 0.0.0.255 network 10.2.1.0 0.0.0.255 # return