What is MTU?

[ericfjchen]

# netstat -in
Name Mtu Network Address Ipkts Ierrs Opkts Oerrs Coll
lan1 1500 10.xx.xx.0 10.xx.xx.21 126236617 0 2236321179 0
0
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Can you explain what MTU is?

[Muthukumar_5]

MTU referers Maximum Transfer Unit. It specifies maximum number of transfer units in the interface.

hth.

[Pete Randall]

Maximum Transmission Unit


Pete

[Muthukumar_5]

Another good definition as,

The Maximum Transmission Unit (MTU) is a parameter that determines the largest datagram than can be transmitted by an IP interface (without it needing to be broken down into smaller units). The MTU should be larger than the largest datagram you wish to transmit unfragmented. Note: this only prevents fragmentation locally. Some other link in the path may have a smaller MTU: the datagram will be fragmented at that point. Typical values are 1500 bytes for an ethernet interface, or 576 bytes for a SLIP interface.

hth.

[Raj D.]

Hi ericfjchen ,


MTU is Maximum Transmission Unit .
The Maximum Transmission Unit (MTU) is a parameter that determines the largest datagram than can be transmitted by an IP interface

To find the current mtu size :
# netstat -i | grep -i mtu
# lanadmin -m 0

To change the mtu size from 1300 to 1500, of interface with PPA number 0 is :

# lanadmin -M 1500 0

Cheers ,

Raj.
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[Florian Heigl (new acc)]

For Your information, the MTU also has a friend called MRU (Maximum Response Unit), which is helpful with WAN scenarios were some line has a lower paket size.

i.e. when routing through a DSL VPN or Wavelan bridge line, it can be helpful to lower both values to the maximum packet size that line handles (i.e. 1462bytes) so that less fragmentation of the packets well be neccessary. This can help to lower WAN latencies a bit as the packets won't be broken into pieces by routers on the way Your data takes.

[KRS_1]

it's used to set transmitting unit size.

MTU - Maximum Number of bytes that can be tranmitted in one packet.


Thanks and Regards

KRS