FTOS Configuration Guide for the C-Series - Force10 Networks

Link Dampening Support for XML
View the output of the following show commands in XML by adding | display xml to the end of the
command:
• show interfaces dampening
• show interfaces dampening summary
• show interfaces interface x/y
Configuring MTU Size on an Interface
The E-Series supports a link Maximum Transmission Unit (MTU) of 9252 bytes and maximum IP MTU of
9234 bytes. 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, FTOS divides the
packet into fragments no bigger than the size set in the ip mtu command.
In FTOS:
MTU = Entire Ethernet packet (Ethernet header + FCS + payload)
Since different networking vendors define MTU differently, check their documentation when planing
MTU sizes across a network.
Table 20 lists the range for each transmission media.
Table 20 MTU Range
Transmission Media MTU Range (in bytes)
Ethernet 594-9252 = link MTU
576-9234 = IP MTU
Link Debounce Timer
Link Debounce Timer is supported on platform e.
The Link Debounce Timer feature isolates upper layer protocols on Ethernet switches and routers from
very short-term, possibly repetitive interface flaps often caused by network jitter on the DWDM equipment
connecting the switch and other devices on a SONET ring. The Link Debounce Timer delays link change
notifications, thus decreasing traffic loss due to network configuration. All interfaces have a built-in timer
to manage traffic. This feature extends the time allowed by the upper layers.
278 Interfaces