Brocade MLX Series and Brocade NetIron XMR Diagnostic Guide ...

RPF 5• If you disable OSPF, the Brocade NetIron XMR and Brocade MLX series router removes all OSPFconfiguration information from the running configuration. In addition, after disabling OSPF,when you save the configuration to the startup configuration file, all configuration informationfor OSPF is removed from the startup configuration file.The CLI displays a warning message similar to the following example.Brocade(config-ospf-router)# no router ospfrouter ospf mode now disabled. All ospf config data will be lost when writingto flash!If you have disabled OSPF but have not yet saved the startup configuration file and reloadedthe software, you can restore the configuration information by re-entering the router ospfcommand to enable the protocol. If you have already saved the startup configuration file andreloaded the software, the information is gone.If you are testing an OSPF configuration and are likely to disable and re-enable OSPF, you maywant to make a backup copy of the startup configuration file before you begin. Then, if youremove the configuration information by saving the configuration after disabling the protocol,you can restore the configuration by saving the backup copy of the startup configuration fileonto the flash memory.Common diagnostic scenarios• A third-party router and a Brocade router are both receiving bad OSPF packets.This indicates that the carrier may be the source of the corruption.• The graceful restart process times out on a Brocade MLX-32 or NetIron XMR 32000 system.For routers that are configured for graceful restart and intended for use in hitless upgrades,you must change the OSPF dead interval to 60 seconds to prevent timeouts.• There are frequent OSPF link flapping events.This issue is resolved by upgrading the software version to include the latest patches.RPFReverse Path Forwarding (RPF) prevents malicious users from spoofing a source IP address. It doesthis by checking that the source address specified for a packet is received from a network to whichthe router has access. Packets with invalid source addresses are not forwarded. Packets that failthe RPF test can be logged.RPF show commandsThis section describes the show commands that display RPF information.show ip interfaceSyntax: show ip interface ethernet The parameter specifies the slot and port number of the Ethernet interface.This command displays information about RPF configurations and packets that have been droppedbecause they failed the RPF check, as shown in the following example in bold.Brocade MLX Series and Brocade NetIron XMR Diagnostic Guide 15353-1002426-02