Users Guide

Table Of Contents
Related
Commands
show ip route view the switch routing table.
show ipv6 route display the IPv6 routes.
ip mtu
Set the IP MTU (frame size) of the packet the RPM transmits for the line card interface. If the packet must be fragmented, Dell
EMC Networking OS sets the size of the fragmented packets to the size specified in this command.
Syntax
ip mtu value
To return to the default IP MTU value, use the no ip mtu command.
Parameters
value
Enter the maximum MTU size if the IP packet is fragmented. The range is from 576
to 9234. The default is 1500 bytes.
Defaults 1500 bytes
Command Modes INTERFACE (Gigabit Ethernet and 10-Gigabit Ethernet interfaces)
Command
History
This guide is platform-specific. For command information about other platforms, see the relevant Dell
EMC Networking OS Command Line Reference Guide.
Verison Description
9.8(0.0P5) Introduced on the S4048-ON.
9.8(0.0P2) Introduced on the S3048-ON.
9.2(1.0) Introduced on the Z9500.
8.3.19.0 Introduced on the S4820T.
8.3.7.0 Introduced on the S4810.
8.1.1.0 Introduced on the E-Series.
6.1.1.0 Introduced on the E-Series.
Usage
Information
When you enter the no mtu command, Dell EMC Networking OS reduces the ip mtu value to 1536 bytes.
To return the IP MTU value to the default, use the no ip mtu command.
Starting with Dell EMC Networking OS Release 9.2(0.2), the ip mtu command is not supported to
configure the IP MTU value that is used when the IP packet is fragmented. Instead of having to configure
the IP MTU value, this value is automatically computed by the software when you configure an interface.
As a result, the ip mtu command is not available for configuration. However, you can continue to specify
the link MTU value by using the mtu command.
Compensate for Layer 2 header when configuring link MTU on an Ethernet interface or Dell EMC
Networking OS may not fragment packets. If the packet includes a Layer 2 header, the difference
between the link MTU and IP MTU (the ip mtu command) must be enough bytes to include for the
Layer 2 header.
Link MTU and IP MTU considerations for Port Channels and VLANs are as follows
Port Channels:
All members must have the same link MTU value and the same IP MTU value.
The Port Channel link MTU and IP MTU must be less than or equal to the link MTU and IP MTU values
configured on the channel members. For example, if the members have a link MTU of 2100 and an IP
MTU 2000, the Port Channels MTU values cannot be higher than 2100 for link MTU or 2000 bytes for
IP MTU.
VLANs:
All members of a VLAN must have same IP MTU value.
Members can have different Link MTU values. Tagged members must have a link MTU 4 bytes higher
than untagged members to account for the packet tag.
790
IPv4 Routing