Testing network configuration

The testing network is a virtual network composed of several entities of type Host or Router. In reality these entities corresponds to independant Unix terminal shells connected to the same Unix station having the vrouter program running. What makes the difference between a Router entity and a Host entity is that in the Host entity the IP forwarding as well as the VRIP protocol are disabled, this can be performed by the vrouter command line by typing : vrip off to disable the vrip protocol ( the vrip on enables it again ) , and the command forward off will disables IP forwarding for the Host.

Figure 4.1: Vrouter testing framework

In the figure we have three hosts H_8, H_7 and H_6 connected to three links DL8, DL7 and DL6. We have also two routers GW 7-8 and GW 6-7-8. In the following I will present the configurations and settings for each entity mentionned in the figure :

• The host H_8 : This is a simple host conencted to the data-link 8 (DL 8) by its interface which have the IP address 154.45.8.22 , This host will deliver packets to the gateway GW 7-8 when it wants to send packets to other hosts not in the datalink 8. the following is the configuration file for the The host H_8 :
  vrip off
  forward off
  interface addr 154.45.8.22 link 8
  route 0.0.0.0 gw 154.45.8.1

  the first two lines will configure the entity as a host by disabeling the IP forwarding and by disabeling the VRIP protocol. the third line adds an interface with the IP address 154.45.8.22 to the host and the last line will set a single routing rule for the host saying that ; default route for outgoing packets is the interfce with the IP address 154.45.8.1.

• The host H_7 : This is a simple host conencted to the data-link 7 (DL 7) by its interface which have the IP address 154.45.7.22 , This host will deliver packets to the gateway GW 7-8 when it wants to send packets to other hosts not in the datalink 8. the following is the configuration file for the The host H_7 :
  vrip off
  forward off
  interface addr 154.45.7.22 link 7
  route 0.0.0.0 gw 154.45.7.1

  the first two lines will configure the entity as a host by disabeling the IP forwarding and by disabeling the VRIP protocol. the third line adds an interface with the IP address 154.45.7.22 to the host and the last line will set a single routing rule for the host saying that ; default route for outgoing packets is the interfce with the IP address 154.45.7.1.

• The host H_6 : This is a simple host conencted to the data-link 6 (DL 6) by its interface which have the IP address 154.45.6.22 , This host will deliver packets to the gateway GW 7-6 when it wants to send packets to other hosts not in the datalink 6. the following is the configuration file for the The host H_6 :
  vrip off
  forward off
  interface addr 154.45.6.22 link 6
  route 0.0.0.0 gw 154.45.6.1

  the first two lines will configure the entity as a host by disabeling the IP forwarding and by disabeling the VRIP protocol. the third line adds an interface with the IP address 154.45.6.22 to the host and the last line will set a single routing rule for the host saying that ; default route for outgoing packets is the interfce with the IP address 154.45.6.1.

• The host GW 7-8 : This is a router connected to the datalinks (DL 7) and (DL 8) by its two interfaces 154.45.7.1 and 154.45.8.1 , initially the routing table of the router is empty. The following is the configuration file for GW 7-8 :
  vrip on
  forward on
  interface addr 154.45.8.1 link 8
  interface addr 154.45.7.1 link 7
  route 154.45.8.0 gw 154.45.8.1
  route 154.45.7.0 gw 154.45.7.1

  We switch on the VRIP protocol as well as the IP forwarding to make this entity act as a router. we also add two routes to the networks 154.45.7.0 and to the 154.45.8.0 through the interfaces 154.45.7.1 and 154.45.8.1 successively.

• The host GW 6-7-8 : This is a router connected to the datalinks (DL 6), (DL 7) and (DL 8) by its interfaces 154.45.6.1, 154.45.7.2 and 154.45.8.2 , initially the routing table of the router is empty. The following is the configuration file for GW 6-7-8 :
  vrip on
  forward on
  interface addr 154.45.8.2 link 8
  interface addr 154.45.7.2 link 7
  interface addr 154.45.6.1 link 6
  route 154.45.6.0 gw 154.45.6.1
  route 154.45.7.0 gw 154.45.7.2
  route 154.45.8.0 gw 154.45.8.2

  We switch on the VRIP protocol as well as the IP forwarding to make this entity act as a router. we also add three routes to the networks 154.45.6.0, 154.45.7.0 and to the 154.45.8.0 through the interfaces 154.45.6.1, 154.45.7.2 and 154.45.8.2 successively.