How to set permanent mtu size for ppp0

Question

Every time I connect to my VPN, I should run

sudo ifconfig ppp0 mtu 1300

How could I make it permanent?

I am using Ubuntu 14.04.

score 3 · Answer 1 · answered May 31 '17 at 09:18

I've tried to apply Farshad's solution on ubuntu 16, and it wasn't working.

Only small fix was needed there - remove sudo inside your script, because everything inside /etc/network/if-up.d/ dir is already run as root user

#!/bin/sh

if [ "$IFACE" = "ppp0" ]; then
    ifconfig ppp0 mtu 1300
fi

score 2 · Answer 2 · answered Aug 25 '15 at 06:07

2

You can define the mtu setting inside the /etc/ppp/options file. The setting should already be present in the options file but should be commented out by default.

answered Aug 25 '15 at 06:07

ayaz

483
3
10

It's not working, I diconnect and connect again but still shows 1400 mtu size – Mohse Taheri Aug 25 '15 at 06:26
@MohseTaheri: You will have to look into the PPTP config file (`/etc/pptpd.conf`) to see what file is defined for the `option` setting. By default, PPP looks in `/etc/ppp/options` but on Debian systems I have seen that the setting is overwritten to look into `/etc/ppp/pptpd-options`. You may have to make changes accordingly. – ayaz Aug 25 '15 at 07:08
it read `/etc/ppp/options` because when I set wrong mtu size it shows me an error but after setting correct value it doesn't change the mtu size after connection – Mohse Taheri Aug 25 '15 at 07:10
This worked on Ubuntu 22.04, been looking for this solution for a while – Phil Cook Sep 21 '22 at 10:16

score 2 · Answer 3 · edited May 23 '17 at 11:33

2

As I said at this Link

You can make your custom script

at this address : /etc/network/if-up.d,

#!/bin/sh

if [ "$IFACE" = "ppp0" ]; then
    sudo ifconfig ppp0 mtu 1300
fi

finally make executable and enjoy from your life ...

edited May 23 '17 at 11:33

Community

1

answered Aug 25 '15 at 07:02

Farshad

121
3

score 1 · Accepted Answer · edited May 23 '17 at 12:41

1

as farshad said in following link:

https://stackoverflow.com/questions/32196425/how-to-set-permanent-mtu-size-for-ppp0/32196605#32196605

the answer is add new file inside /etc/network/if-up.d/:

#!/bin/sh

if [ "$IFACE" = "ppp0" ]; then
    sudo ifconfig ppp0 mtu 1300
fi

edited May 23 '17 at 12:41

Community

1

answered Aug 25 '15 at 06:57

Mohse Taheri

141
1
5

How to set permanent mtu size for ppp0

4 Answers4