3Com Switch 7700 Configuration Manual page 129

Perform the following configuration in OSPF view.
Table 46 Setting OSPF Route Preference
Operation
Configure a priority for OSPF for comparing
with the other routing protocols
Restore the default protocol priority
By default, the OSPF preference is 10, and the imported external routing protocol
is 150.
Configuring OSPF Route Filtering
Perform the following configuration in OSPF view.
Table 47 Enabling OSPF to Filter the Imported Routes
Operation
Enable OSPF filtering of the imported global
routing information
Disable filtering of the imported global routing
information
By default, OSPF does not filter the imported and distributed routing information.
For a detailed description, see "IP Routing Policy".
Configuring Filling the MTU Field When an Interface Transmits DD Packets
OSPF routers use the DD (Database Description) packets to describe their own
LSDs 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.
Table 48 Configuring Filling MTU Field When an Interface Transmits DD Packets
Operation
Enable an interface to fill in the MTU field
when transmitting DD packets
Disable the interface to fill MTU when
transmitting DD packets
By default, the interface does not fill in the MTU field when transmitting DD
packets, and the MTU in the DD packets is 0.
Disabling the Interface to Send OSPF Packets
Use the silent-interface command to prevent the interface from transmitting
OSPF packets.
Command
preference [ ase ] preference
undo preference [ ase ]
Command
filter-policy { acl-number | ip-prefix
ip-prefix-name | gateway prefix-list- name }
import
undo filter-policy { acl-number | ip-prefix
ip-prefix-name | gateway prefix- list-name }
import
Command
ospf mtu-enable
undo ospf mtu-enable
OSPF 121