Netgear FSM726v3 7200 managed switch v8.x CLI reference manual - Page 247

Format Mode ip netdirbcast Interface Config Managed Switch CLI Manual, Release 8.0 no ip netdirbcast This command disables the forwarding of network-directed broadcasts. When disabled, network directed broadcasts are dropped. Format Mode no ip netdirbcast Interface Config ip mtu This command sets the IP Maximum Transmission Unit (MTU) on a routing interface. The IP MTU is the size of the largest IP packet that can be transmitted on the interface without fragmentation. The software currently does not fragment IP packets. • Packets forwarded in hardware ignore the IP MTU. • Packets forwarded in software are dropped if they exceed the IP MTU of the outgoing interface. Packets originated on the router, such as OSPF packets, may be fragmented by the IP stack. The IP stack uses its default IP MTU and ignores the value set using the ip mtu command. OSPF advertises the IP MTU in the Database Description packets it sends to its neighbors during database exchange. If two OSPF neighbors advertise different IP MTUs, they will not form an adjacency. (unless OSPF has been instructed to ignore differences in IP MTU with the ip ospf mtu-ignore command.) Note: The IP MTU size refers to the maximum size of the IP packet (IP Header + IP payload). It does not include any extra bytes that may be required for Layer-2 headers. To receive and process packets, the Ethernet MTU (see "mtu" on page 35) must take into account the size of the Ethernet header. Default Format Mode 1500 bytes ip mtu Interface Config Routing Commands v1.0, July 2009 4-12