Kontron AT890X Full-Size CLI - Manual (Page 122)

Routing Commands AT8901/2/3
AT8901/2/3 CLI Reference Manual Page 3 - 10
3.2.8.1 no ip netdirbcast
This command disables the forwarding of network-directed broadcasts. When
disabled, network directed broadcasts are dropped.
Format no ip netdirbcast
Mode Interface Config
3.2.9 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. FASTPATH 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 out-
going 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 (2.1.5 “mtu” on page 2 - 3) must take into account the
size of the Ethernet header.
Default 1500 bytes
Format ip mtu <68-1500>
Mode Interface Config
3.2.9.1 no ip mtu
This command resets the ip mtu to the default value.
Format
no ip mtu
Mode Interface Config
3.2.10 encapsulation
This command configures the link layer encapsulation type for the packet. The
encapsulation type can be
ethernet
or
snap
.
Default ethernet
Format encapsulation {ethernet | snap}
Mode Interface Config