Re: [lwip-users] PPP phase dead every 2 hours

[Ajay Bhargav (SiWi)]

Hi Nishant,

 

It is normal for network providers to close PDP context. And 2hrs seems to be common duration as per what I have tested. All you can do is simply reconnect. Moreover IP provided by most service providers are not public so you wont be able to run a server in most cases and IP will change all the time for sure.

 

Regards,

Ajay B.

 

 

From: Sylvain Rochet
Sent: Thursday, June 21, 2018 2:19 PM
To: Mailing list for lwIP users
Subject: Re: [lwip-users] PPP phase dead every 2 hours

 

Hi Nishant,

 

On Thu, Jun 21, 2018 at 12:37:09PM +0545, Nishant Agrawal wrote:

> Hello,

>

> I am using the ppp stack, using a modem to keep a device online and it is

> sending ping requests every 30 seconds. The problem is that roughly every 2

> hours, I end up with error, PPPERR_CONNECT. The phase change generally is

> as follows,

>

> PHASE_NETWORK

> PHASE_ESTABLISH

> PHASE_DISCONNECT

> PHASE_DEAD

>

> The PHASE_NETWORK and ESTABLISH happens simultaneously. PHASE_DISCONNECT

> happens about 5 seconds later and the phase goes to DEAD immediately as

> well. After PHASE_DEAD, I get the error, PPPERR_CONNECT.

 

That's the normal clean disconnection behavior. I believe the peer sent

you a LCP TermReq request. Could you check that ? (Using PPP_DEBUG and

PRINTPKT_SUPPORT support).

 

 

> I believe that the issue is related to the IP lease time. Because the

> time is more or less consistent and I am seeing the same pattern with

> 2 different prototypes that are on test. And every time I reconnect I

> get a new IP. So my question is, is there any way for me to request a

> renew of the old connection, like something that can be done with

> DHCP.

 

This is no such renew thing in PPP. If the peer change your local IP

address it means it really want to change it or just they don't care at

all and give a random one each time you connect.

 

There is no such thing of IP lease time as well, if a peer disconnect

you every two hours it means the peer want you to reconnect every two

hours.

 

However, you could try with another modem brand/model, I doubt the issue

is on the modem side (once in a while :p) but some of them are,

especially cellular ones, are doing stupid things or just full of bugs.

 

 

> Or what I can I do to keep the device connected?

 

Well, ask your ISP to stop disconnecting you every two hours :-)

 

 

Sylvain