Routing Commands
233
ProSafe M4100 and M7100 Managed Switches
ip netdirbcast
This command enables the forwarding of network-directed broadcasts. When enabled,
network directed broadcasts are forwarded. When disabled they are dropped.
Default
Format ip netdirbcast
Mode
no ip netdirbcast
This command disables the forwarding of network-directed broadcasts. When disabled,
network directed broadcasts are dropped.
Format no ip netdirbcast
Mode
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, might 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 might
be required for Layer-2 headers. To receive and process packets,
the Ethernet MTU (see mtu on page 23) must take into account the
size of the Ethernet header.
disabled
Interface Config
Interface Config
Default 1500 bytes