Is MTU 1400 or 1500?

What is the most optimal MTU size?

Is there any practical application of using higher MTU sizes for network interfaces?

There are two main reasons for using larger MTUs. First, MTU size is limited by the protocol; eg TCP must send a maximum of 65,535 bytes and UDP must send a maximum of 65,535 bytes. However, the size is also limited by the network. Some (for example, some Cisco routers) have a limit of 1536 bytes in the wire and the actual MTU on the wire is usually a bit smaller than the largest possible message.

Second, even though you can send a packet bigger than the MTU, it will usually not be transferred correctly. The reason is that the lower layer may not know how to fragment the packet; the higher layer may not know how to reassemble the packet correctly. To avoid this, the packet is usually split into multiple smaller packets.

To avoid fragmentation, you will often want to send data in blocks. If you need to send a large number of small messages you may want to pack them into one packet (using a protocol like UDT) instead of sending them as separate packets.

Is it better to have a higher or lower MTU?

If you have low end hardware and limited internet speed, is it better to increase or decrease the MTU?

As far as I understand, it has something to do with how many small data packages fit within the packet, but isn't this all irrelevant? My limited understanding goes something like this: Your device has two ethernet ports. One can handle a maximum of 1500 packets of 10 bytes. The other can handle a maximum of 590 of 4 bytes. Increasing the MTU would enable you to transfer more data at once because there is more space within the packet itself.

Am I doing anything wrong here? The MTU is the total size of a packet, a packet contains many "data" packets so to speak (the data field), the MTU is the maximum amount of data that you can transfer in one packet. It's the largest data packet that the sender and receiver can agree on before they need to fragment the packet and send smaller packets.

If a packet is too large to be delivered to its destination without being split up then the packets will have to be dropped by the receiver (it may also have to be dropped by the network interface). By reducing the MTU you can increase the maximum size of the packet and thus increase your throughput.

Is MTU 1400 or 1500?

Hi All.

I am looking at purchasing a new road bike. The one feature that is giving me the most trouble is the MTU 1200 (or MTU 1400 or 1500) overdrive. I have read many threads here on this subject but it appears to be split down the middle, with people either wanting an overdrive or not.

My riding is mostly on roads and I like to keep the bike a little bit more upright than most people. I am not a racer, I am just out for a nice ride and some fun. However, when I am racing I would like to be able to go as fast as possible.

The other consideration is that I would prefer a bike that fits me well. I am 5'11" and 165lbs. I would like a bike that will fit my size and feel comfortable when I am putting out full effort.

In addition, I am looking for a bike with a very easy shifting. It sounds like the most popular MTUs have three clicks (or "cables"?) per gear which can be quite challenging when shifting.

So, after doing a lot of reading I am leaning towards the Madone or Domane. Any thoughts? Thanks in advance! Last edited by lvh on Wed Jul 11, 2025 8:46 pm, edited 1 time in total. I love the Madone. You are correct that there are many opinions on whether or not to get an overdrive. You are also right about the shifting. I've never had any issues with the MTU overdrives and, when you consider the fact that the overdrive is only a handful of clicks per gear, it's really not that bad. The only issue I have had with the overdrive is that I sometimes have to change the chain a couple of times before it gets good and tight. So, if you have any problems with the shifting, it's worth getting an overdrive.

The other thing I think you may want to look at is how much you want to spend on accessories.

What should my switch MTU be?

So I'm going to be doing a network switch for a home theater network for some friends and family.

Basically I need to have 4x 10/100 and 1x GigE (for the router), my current switch is a Tundra 2200E and right now I don't have any hard information on what's the best switch for my needs. I know people like the QOS, but I don't really know if that applies to me.

I currently have a Tundra 2200E, I need to go to a switch, but I would prefer a gigabit switch. Can anyone point me in the right direction? You can get a dual-port gigabit switch (eg. That will let you do a maximum of 12x 100-Mbps Ethernet ports. It can be configured as a failover switch (which we'll discuss later) or used to provide gigabit networking between two gigabit LAN cards (ie. To bridge two 10/100 devices). Or you can buy a dual-port gigabit switch with enough ports to support the four gigabit Ethernet devices plus whatever your gigabit LAN needs may be.

With a dual-port gigabit switch, you won't have trouble configuring WAN ports (or failover) on either port. If you decide to use the third or fourth port for something else, you just have to assign them different IP addresses (via DHCP) on both ports, and reconfigure them to use a different IP address on the third/fourth port. You also won't have to worry about port collision.

I wouldn't consider a dual-port gigabit switch to be a "home theater network switch", because the typical home-theater applications are not supported by these kinds of switches. You'd use a home-theater-specific switch, such as the Netgear FS9000 series. The "FS" stands for home theater. Netgear has a ton of models and sizes (as well as some Cisco switches and some Linksys stuff that they sell as home-theater switches).

The single-port gigabit and 10/100 Ethernet switches also have a huge selection (including the Netgear FS5100 gigabit switches).