Switch 7700 Configuration Guide

OSPF 93
By default, OSPF does not filter the imported and distributed routing information.
For detailed description, see “IP Routing Policy”.
Configure Filling the MTU Field When an Interface Transmits DD Packets
OSPF-running routers use the DD (Database Description) packets to describe their
own LSDBs when synchronizing the databases.
By default, the MTU field in DD packets is 0. You can manually specify an interface
to fill in the MTU field in a DD packet when it transmits the packet. The MTU
should be set to the real MTU on the interface.
Perform the following configuration in VLAN interface view.
By default, the interface does not fill in the MTU field when transmitting DD
packets and the MTU in the DD packets is 0.
Disable the Interface to Send OSPF Packets
To prevent OSPF routing information from being acquired by the routers on a
network, use the silent-interface command to disable the interface to transmit
OSPF packets.
Perform the following configuration in OSPF view.
By default, all the interfaces are allowed to transmit and receive OSPF packets.
After an OSPF interface is set to silent status, the interface can still advertise its
direct route. However, the OSPF calling packets of the interface are blocked, and
no neighboring relationship can be established on the interface. This enhances
OSPF’s ability to adapt to the network, which reduces the consumption of system
resources.
Reset the OSPF Process
If the undo ospf command is executed on a router and then the ospf command
is used to restart the OSPF process, the previous OSPF configuration is lost. With
the reset ospf all command, you can restart the OSPF process without losing the
previous OSPF configuration.
Tabl e 46 Configure Filling MTU Field when an Interface Transmits DD Packets
Operation Command
Enable an interface to fill in
the MTU field when
transmitting DD packets
ospf mtu-enable
Disable the interface to fill
MTU when transmitting DD
packets
undo ospf mtu-enable
Tabl e 47 Disable the Interface to Send OSPF Packets
Operation Command
Disable the interface to send OSPF
packets
silent-interface silent-interface-type
silent-interface-number
Enable the interface to send OSPF
packets
undo silent-interface silent-interface-type
silent-interface-number