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

[Sylvain Rochet]

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

signature.asc
Description: Digital signature