Interfaces | 505Configure MTU size on an InterfaceThe E-Series supports a link Maximum Transmission Unit (MTU) of 12000 bytes and maximum IP MTUof 9234 bytes. The link MTU is the frame size of a packet, and the IP MTU size is used for IPfragmentation. If the system determines that the IP packet must be fragmented as it leaves the interface,FTOS divides the packet into fragments no bigger than the size set in the ip mtu command.In FTOS, MTU is defined as the entire Ethernet packet (Ethernet header + FCS + payload)Since different networking vendors define MTU differently, check their documentation when planingMTU sizes across a network.Table 23-5 lists the range for each transmission media.Link Bundle MonitoringLink Bundle Monitoring is supported only on platform:Monitoring linked LAG bundles allows traffic distribution amounts in a link to be monitored for unfairdistribution at any given time. A threshold of 60% is defined as an acceptable amount of traffic on amember link. Links are monitored in 15-second intervals for three consecutive instances. Any deviationwithin that time causes a Syslog to be sent and an alarm event to be generated. When the deviation clears,another Syslog is sent and a clear alarm event is generated.The link bundle utilization is calculated as the total bandwidth of all links divided by the totalbytes-per-second of all links. If monitoring is enabled, the utilization calculation is performed when theutilization of the link-bundle (not a link within a bundle) exceeds 60%.Enable link bundle monitoring using the ecmp-group command.View all LAG link bundles being monitored using the show running-config ecmp-group command.Ethernet Pause FramesEthernet Pause Frames is supported on platforms c e sThreshold Settings are supported only on platforms: c sTable 23-5. MTU RangeTransmission Media MTU Range (in bytes)Ethernet 594-12000 = link MTU576-9234 = IP MTU
