Catalog

Experimental topology

Experiment steps and configuration

ip configuration

RA
#
 sysname RA
#
interface GigabitEthernet0/0/0
 ip address 10.1.1.1 255.255.255.0 
#


RB
#
 sysname RB
#
interface GigabitEthernet0/0/0
 ip address 10.1.1.2 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 10.1.2.1 255.255.255.0 
#


RC
#
 sysname RC
#
interface GigabitEthernet0/0/0
 ip address 10.1.2.2 255.255.255.0 
#
interface GigabitEthernet0/0/1
 ip address 10.1.3.1 255.255.255.0 
#

RD
#
 sysname RD
#
interface GigabitEthernet0/0/0
 ip address 10.1.3.2 255.255.255.0 
#

Configure ospf and loopback address

RA
#
router id 1.1.1.1 
#
interface LoopBack0
 ip address 1.1.1.1 255.255.255.255 
#
ospf 1 
 area 0.0.0.1 
  network 1.1.1.1 0.0.0.0 
  network 10.1.1.1 0.0.0.0 
#

RB
#
router id 2.2.2.2 
#
interface LoopBack0
 ip address 2.2.2.2 255.255.255.255 
#
ospf 1 
 area 0.0.0.0 
  network 2.2.2.2 0.0.0.0 
  network 10.1.2.1 0.0.0.0 
 area 0.0.0.1 
  network 10.1.1.2 0.0.0.0 
#

RC
#
router id 3.3.3.3 
#
interface LoopBack0
 ip address 3.3.3.3 255.255.255.255 
#
ospf 1 
 area 0.0.0.0 
  network 3.3.3.3 0.0.0.0 
  network 10.1.2.2 0.0.0.0 
 area 0.0.0.2 
  network 10.1.3.1 0.0.0.0 
#

RD
#
router id 4.4.4.4 
#
interface LoopBack0
 ip address 4.4.4.4 255.255.255.255 
#
ospf 1 
 area 0.0.0.2 
  network 4.4.4.4 0.0.0.0 
  network 10.1.3.2 0.0.0.0 
#

experimental result

Test whether RA-RD passes

Change of relationship between RA-RB detected by packet capturing

• A. B sends hello messages to each other to find neighbors. The relationship changes: down - init - two way;
  Then DR and BDR are selected through DD message, and then A and B send their lsdb profiles to the other party through DD message in EXCHANGE state. The relationship between A and B: two-way -- EXSTART -- EXCHANGE,
  Then A and B send lsq and lsu messages in the loading state, and finally send lsack messages in the full state after receiving. The relationship between A and B: EXCHANGE - loading - full.
• In two-way, neighbor relationship is established; in full, neighbor relationship is established; ospf is successful only when neighbor relationship is established.