topic Re: MTU Setting in Full Fibre

MTU Setting

Staro — Sun, 01 May 2016 11:16:53 GMT

Good ~~morning~~ afternoon,

Can I ask is the MTU something that's set on the line by Plusnet ?

My Hub One and Home Hub 5 seem to have an MTU of 1488 which appears to be the reason I'm having the following error over the Playstation Network "The router in use may not support IP Fragments..." in turn giving me a connection error when trying to get online with certain games.

Would buying a replacement Modem/Router with the ability to set the MTU to 1492 likely fix this does anyone know ?

Re: MTU Setting

Terranova667 — Sun, 01 May 2016 19:45:23 GMT

not all routers / modems give the option to set the MTU so don't worry about that, you can set it via the Playstation 3 / 4 which ever your using, go to settings then network and pick manual setup instead of Automatic keep everything on defaults when you get to the MTU change it to 1492, that should do the trick.

Re: MTU Setting

Staro — Sun, 01 May 2016 19:57:28 GMT

Thank you for replying.

I should have mentioned I've tried manually changing the MTU to 1492 (and most other values) across PS3/PS4/PS Vita but unfortunately it doesn't get rid of the error message or the issues when trying to connect to certain games.

Re: MTU Setting

Terranova667 — Sun, 01 May 2016 20:03:51 GMT

HI ok try setting the MTU via Windows command Prompt

Run Command prompt as Administrator ( type Cmd in windows search if you don't know how to get to it )

in the black box that appears type the following for a Wired Connection

netsh interface ipv4 set subinterface "Local Area Connection" mtu=1492 store=persistent

then press Enter it should say OK

for a Wireless connection type the following

netsh interface ipv4 set subinterface "Wireless Network Connection" mtu=1492 store=persistent

Then Press Enter it should say OK

exit the command prompt by typing exit then reboot the PC test on PS3 etc and see if that does it.

Re: MTU Setting

Anonymous — Sun, 01 May 2016 20:17:11 GMT

Have you tried determining the maximum MTU that doesn't give fragmentation ?

There are lots of instructions on the internet to do this, but here's a typical procedure -

DSLReports - Max MTU: How do I find mine?

The important thing is to find the value that works for your router, and not be overly concerned about achieving 1492. For years I had routers that optimally worked with MTU or 1430 or 1458 with no detrimental effects.

First find the maximum MTU for your connection, and set and save that value in the router config.

Reboot the router, and test the connection with the new/lower MTU, and make sure it isn't fragmenting.

Reboot the PS4 and see whether the original error message persists.

If it does, then manually set the PS4 MTU to the same value that you just put in to the router.

DO NOT be tempted to put a higher MTU in the PS4 than what the router is set to.

Re: MTU Setting

npr — Sun, 01 May 2016 20:10:38 GMT

The MTU setting in the PS needs to be the same or less than that of the router.

Try a setting of 1488 or is there a automatic setting?

Re: MTU Setting

Anonymous — Sun, 01 May 2016 20:10:51 GMT

DO NOT try forcing the MTU to 1492 as "Terranova667" is suggesting !

THAT IS WRONG !

Re: MTU Setting

Staro — Sun, 01 May 2016 20:13:29 GMT

For a wired connection it says Element not found

Re: MTU Setting

Terranova667 — Sun, 01 May 2016 20:18:19 GMT

Why is it ?

@Anonymous wrote:

DO NOT try forcing the MTU to 1492 as "Terranova667" is suggesting !

THAT IS WRONG !

i set it that way for me and it works perfectly fine for everything i have connected including PS3 / PS4 so please enlighten me

Re: MTU Setting

Staro — Sun, 01 May 2016 20:21:53 GMT

I have, mine didn't fragment at 1460 + 28 = 1488

Am I right in thinking that by doing the ping MTU fragment prompt, that 1488 is what my router is fixed at ?
Because in work when I tried lowering the MTU setting on a different router the result would always add up to what I lowered it by, if I lowered it to 1492 for example instead of 1500 it would fragment at 1465 but not at 1464 and when I raised it to 1500 for example it would fragment at 1473 and not 1472

I can't edit/save the MTU of the Plusnet Hub One though so maybe a replacement is my only solution ?

Re: MTU Setting

npr — Sun, 01 May 2016 20:23:27 GMT

In that case your router must have a MTU of 1492 or more.
IIRC the HH 5B has a MUT of 1492, whereas the HH 5A is somewhat less

Re: MTU Setting

Staro — Sun, 01 May 2016 20:24:42 GMT

Think my router is set to 1488, I think, I'm kinda new to this
I can change the MTU setting on any of the PS devices to any value but nothing clears it, automatic no longer works either.

Re: MTU Setting

Anonymous — Sun, 01 May 2016 20:32:26 GMT

Terranova667 wrote: i set it that way for me and it works perfectly fine for everything i have connected including PS3 / PS4 so please enlighten me

The point of setting an MTU is to ensure that no device on a connection sends packets that are larger than can be processed by the other devices in a chain which have a lower packet size limit.

If the router has a maximum of 1488 and your PC/PS has an MTU of 1492, then the outgoing packets will fragment (or fail) because they are larger than 1488.

On a home network, the internet connection maximum MTU should be determined and set in the router. All other devices should be the same or lower than the router's MTU, for it to work properly.

Re: MTU Setting

Staro — Sun, 01 May 2016 20:28:29 GMT

Ah hah that's how I quote.

I have a HH5a, same as PN hub 1 from what I've read the last week, guess I need a 5B or the like ?

Edit: Nope that's not how I quote at all

Re: MTU Setting

npr — Sun, 01 May 2016 20:30:00 GMT

Does the PS need a reboot after changing the settings?

Using a MTU of 1488 really should not be causing any problems provided the routers MTU is 1488 or more.
Don't see this as a reason to change routers, although the HH5 may give you other reasons

Re: MTU Setting

Staro — Sun, 01 May 2016 20:31:03 GMT

@Nibiru

As I can't change the MTU of HH5a and PN Hub One shouldn't they already be set at 1492 ?

Re: MTU Setting

Staro — Tue, 03 May 2016 15:00:49 GMT

@npr

More Info:

At first I thought it must be a PS Network issue, rang Plusnet customer service last week and the nice lady said there was nothing they could do and it may be a software fault on Sony's side to which I thought more than likely. After getting in contact with Sony the advice given was to open certain ports on my router, I've never had to do this before on any isp or modem/router but I did anyway and again it did not resolve the problem. It was only until I took my PS Vita to my mate's house on Friday that I realised maybe it's not a PSN issue as it worked without error. Differences being, Router, Service Provider and ADSL2 instead of Fibre. I should be able to check it on Thursday on a Plusnet Business connection, narrowing it down to only router and connection type.

Moderator's note by Adie (Dvorak) edited for readability as it was flowing off screen.

Re: MTU Setting

npr — Sun, 01 May 2016 20:41:44 GMT

Edit: Seriously how do I quote, the tag thing is working but prefer to quote.

Highlight and copy what you want to quote.

In reply click the "insert code" icon, past quote in that window.

No, that's not right

Re: MTU Setting

Browni — Sun, 01 May 2016 20:42:12 GMT

@Staro wrote:

@npr @npr

Yeah I reboot after changing settings

Edit: Seriously how do I quote, the tag thing is working but prefer to quote.

Click Reply under the post you want to quote and then click the Quote button when the reply appears for typing.

Re: MTU Setting

Staro — Sun, 01 May 2016 21:06:11 GMT

Ah it was there from the start, all dark greyed out instead of pink !

Moderator's note by Adie (Dvorak): Full quote of preceding post removed as per the forum rules