LinuxQuestions.org - Default Gateway Not Listed In Routing Table

Hi,

I am trying to configure a network using workstations running FedoraCore 2 and Zebra routing software. My setup looks like:

Code:

                                Internet

                                    |

                                ----------

                                | Cisco  |

                                ----------  192.168.5.100

                                    |

            -------------------------------------------------------------

                  |                    |                      |

  192.168.5.1  --------              --------              --------  192.168.5.3

                |  Z1  |              |  Z2  |              |  Z3  |

  192.168.0.1  --------              --------              --------  192.168.2.1

                  |                    |                      |

                  |                    |                      |

                  X                    X                      X

                  |                    |                      |

                  |                    |                      |

  192.168.0.2  --------              --------              --------  192.168.2.2

              |  Z4  |              |  Z5  |              |  Z6  |

  192.168.10.4 --------              --------              --------  192.168.10.6

                  |                    |                      |

            -------------------------------------------------------------

X = crossover cable
All nodes have subnet mask 255.255.255.0
IP scheme is consistent for Z2 and Z5 (addresses not shown due to space)

In this network setup I do not expect Z1, Z2, and Z3 interfaces to be up all the time. Also, I do not expect the 192.168.10.0 network interfaces to be up all the time either. All of the routers are using OSPF to update their routes.

The problem I am having is trying to set up default gateways for Z4, Z5, and Z6. I can set up default gateways for these routers to be Z1, Z2, and Z3 respectively, but if the 192.168.5.X interface goes down on Z1, Z2, or Z3, the corresponding Z4, Z5, or Z6 router will lose Internet connectivity.

What I want to be able to do is set the default gateway of Z4, Z5, and Z6 to 192.168.5.100 (Cisco), so that if the directly connected router's 192.168.5.X interface goes down, Z4, Z5, and/or Z6 can find a different route to the internet.

I have tried configuring the 192.168.5.100 default gateway using "neat" and editing ifcfg-eth0 and zebra.conf files, but the default gateway is not listed in the routing tables for Z4, Z5, or Z6. Also, if I run the command "route add default gw 192.168.5.100 eth0" I see the error message "SIOCADDRT: Network is unreachable" even though the 192.168.5.0 network is in the routing tables for Z4, Z5, and Z6.

If you have any suggestions or know how to configure this, your input would be greatly appreciated. Thank you.