Administrator Guide

Congure MTU Size on an Interface
In Dell Networking OS, Maximum Transmission Unit (MTU) is dened as the entire Ethernet packet (Ethernet header + FCS + payload).
The link MTU is the frame size of a packet, and the IP MTU size is used for IP fragmentation. If the system determines that the IP packet
must be fragmented as it leaves the interface, Dell Networking OS divides the packet into fragments no bigger than the size set in the ip
mtu command.
NOTE: Because dierent networking vendors dene MTU dierently, check their documentation when planning MTU sizes
across a network.
The following table lists the range for each transmission media.
Transmission
Media
MTU Range (in bytes)
Ethernet
592-9216 = link MTU
576-9398 = IP MTU
Link Bundle Monitoring
Monitoring linked LAG bundles allows trac distribution amounts in a link to be monitored for unfair distribution at any given time. A
threshold of 60% is dened as an acceptable amount of trac on a member link. Links are monitored in 15-second intervals for three
consecutive instances. Any deviation within that time sends Syslog and an alarm event generates. When the deviation clears, another
Syslog sends and a clear alarm event generates.
The link bundle utilization is calculated as the total bandwidth of all links divided by the total bytes-per-second of all links. If you enable
monitoring, the utilization calculation is performed when the utilization of the link-bundle (not a link within a bundle) exceeds 60%.
To enable and view link bundle monitoring, use the following commands.
• Enable link bundle monitoring.
ecmp-group
• View all LAG link bundles being monitored.
show running-config ecmp-group
• Enable link bundle monitoring on port channel interfaces.
link-bundle-monitor enable
Dell(conf-if-po-10)#link-bundle-monitor enable
• Congure threshold level for link bundle monitoring.
link-bundle-distribution trigger-threshold
Dell(conf)#link-bundle-distribution trigger-threshold
• View the link bundle monitoring status.
show link-bundle-distribution
Using Ethernet Pause Frames for Flow Control
Ethernet pause frames and threshold settings are supported on the Dell Networking OS.
Ethernet Pause Frames allow for a temporary stop in data transmission. A situation may arise where a sending device may transmit data
faster than a destination device can accept it. The destination sends a PAUSE frame back to the source, stopping the sender’s
transmission for a period of time.
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Interfaces