# Changing mtu in rp-pppoe?

## anidabi

The topic says it all, but I like to explain myself a little.

I have had a lot of broblem lately with my dsl connection, more accurately with my 10/10 vdsl connection. For some reason it disconnects allways in high speeds. I am talking about like more than 500kB/s speeds. Often it disconnects with lower speed too.

When my connection goes up, it uses mtu of 1492, witch I thing is too much and maybe is the reason for braking my connection. So I want to test if lower mtu solves my broblem, but I don't know how?  :Rolling Eyes:  My default /etc/ppp/pppoe.conf doesn't have any options for changing the mtu, neither does /etc/ppp/options-pppoe. So I tried anyway putting mtu 1452 and mru 1452 in options-pppoe with no results.  :Sad: 

I don't understant how rp-pppoe works in gentoo, other than that it is a lot different than in debian. So please help me!

----------

## Running Pinata

```
ifconfig eth0 mtu 1500
```

and the standard ethernet mtu is 1500.

and I'm sure Mtu isn't the problem, go yell at your isp.

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## anidabi

 *Running Pinata wrote:*   

> 
> 
> ```
> ifconfig eth0 mtu 1500
> ```
> ...

 

Okey, that did it! Time to start testing.  :Smile: 

But hey, is there anyway how to make specific mtu when bringing ppp up? I have added rp-pppoe at default boot.

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## anidabi

Hmm... changing mtu on the fly brokes the whole connection and brings ppp0 down!  :Sad:  It seem that it doesn't work like that.

So is there any way how to give specific mtu on dial-up?

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## UberLord

/etc/ppp/options

mru 1492

mtu 1492

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## anidabi

 *UberLord wrote:*   

> /etc/ppp/options
> 
> mru 1492
> 
> mtu 1492

 

I tried mtu and mru options in /etc/ppp/option and in /etc/ppp/option-pppoe files, but it didn't change a thing. Mtu and mru are still 1492. Then I changed 

```
PPPOE_EXTRA="" and PPPD_EXTRA=""
```

 lines in /etc/ppp/pppoe.conf, into 

```
PPPOE_EXTRA="mtu 1452 mru 1452" and PPPD_EXTRA="mtu 1452 mru 1452"
```

 and it worked. Now mtu and mru are 1452 at dial-up.  :Smile: 

But of course with my luck, it didn't help at all, it still disconnects at high speeds.  :Sad:  Guess I have to make few phone calls to my isp.

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