eNSP Notes on the OSPF Virtual Link Lab

Experiment Overview

1. Build an OSPF network
2. Use virtual links to logically connect Area A2 with A0
3. Modify OSPF cost values to prefer the R1 path, with the R2 path as backup
4. Use virtual links as redundant backup for Area 0
5. Configure virtual link authentication
6. Use a GRE Tunnel to achieve logical connectivity between Area A2 and A0

Experiment Steps Reference

R1 Reference Configuration:

sysname R1
un in en

ospf 10 router-id 10.0.1.1 
 area 0.0.0.0 
  network 10.0.1.0 0.0.0.255 
  network 10.0.12.0 0.0.0.255 
 area 0.0.0.1 
  network 10.0.13.0 0.0.0.255 
  vlink-peer 10.0.2.2 hmac-md5 1 plain nilaogou
  vlink-peer 10.0.3.3 hmac-md5 1 plain nilaogou

R2 Reference Configuration:

un in en
int G0/0/2
ospf cost 10

interface Tunnel0/0/0
 ip address 1.1.1.1 255.255.255.0 
 tunnel-protocol gre
 source 10.0.23.2
 destination 10.0.23.3

ospf 10 router-id 10.0.2.2 
 area 0.0.0.0 
  network 10.0.2.0 0.0.0.255 
  network 10.0.12.0 0.0.0.255 
 area 0.0.0.1 
  network 10.0.23.0 0.0.0.255 
  vlink-peer 10.0.1.1 hmac-md5 1 plain nilaogou
  vlink-peer 10.0.3.3 hmac-md5 1 plain nilaogou

R3 Reference Configuration:

un in en

int G0/0/2
ospf cost 10

interface Tunnel0/0/1
 description 10.0.23.2
 ip address 1.1.1.2 255.255.255.0 
 tunnel-protocol gre
 source 10.0.23.3
 destination 10.0.23.2
 
ospf 10 router-id 10.0.3.3 
 area 0.0.0.1 
  network 10.0.3.3 0.0.0.0 
  network 10.0.13.0 0.0.0.255 
  network 10.0.23.0 0.0.0.255 
  vlink-peer 10.0.1.1 hmac-md5 1 plain nilaogou
  vlink-peer 10.0.2.2
 area 0.0.0.2 
  network 10.0.34.0 0.0.0.255 

R4 Reference Configuration:

un in en

ospf 10 router-id 10.0.4.4 
 area 0.0.0.2 
  network 10.0.4.4 0.0.0.0 
  network 10.0.34.0 0.0.0.255 

Key Points

GRE Tunnel

interface Tunnel0/0/1   Specify the Tunnel interface
 description 10.0.23.2   Specify the description of the Tunnel interface
 ip address 1.1.1.2 255.255.255.0 
 tunnel-protocol gre   The tunnel protocol of the Tunnel interface is GRE
 source 10.0.23.3   Specify the source address of the Tunnel
 destination 10.0.23.2   Specify the destination address of the Tunnel

OSPF Virtual Link and Authentication

vlink-peer 10.0.1.1 hmac-md5 1 plain nilaogou
vlink-peer    ID    MD5 encryption   key ID 1   plain (plaintext)   nilaogou (password)

For details, see: Click to view the Huawei Command Reference