MTU size > 1500?

johnifanx98

Many times I see in the text book saying MTU =1500. However, in a 1Gbps network I often see frames of several KB or even tens of KB in the wireshark captured data. Does it mean the MTU could be much bigger in 1 high speed LAN?

networker050184

Yes the maximum MTU is configurable, but the default is 1500 for ethernet and you can run into fragmentation issues if you are not careful when changing it.

Balantine

Yes but all devices must support it, end-to-end. Otherwise it will get re-datagrammed.

EDIT: Another thing to be careful of is your OS and type of devices... they calculate the MTU differently defending on headers...

johnifanx98

Balantine wrote: »

Yes but all devices must support it, end-to-end. Otherwise it will get re-datagrammed.

EDIT: Another thing to be careful of is your OS and type of devices... they calculate the MTU differently defending on headers...

Are you saying the jumbo frame I see in my wireshark are merged ones?

NotHackingYou

Try this article about jumbo frames
Jumbo frame - Wikipedia, the free encyclopedia