Re: Internet connection redundancy (DSL and 4GLTE)

[BERTRAND Joël <joel.bertrand%systella.fr@localhost>]

Niels Dettenbach a écrit :
> Am Mittwoch, 8. Juni 2022, 09:38:30 CEST schrieb BERTRAND Joël:
>>         Now, I'm trying to automatically change default route (from
>> 192.168.15.20 to 192.168.15.19 and reciprocally) when DSL connection is
>> down.
> there are lot of different ways to implement such a "automatic failover" with 
> different pros and cons.
> 
> The "simplest" but hacky way may be to use ppps ip-up/down / pre-up/down or 
> similiar parameters / scripts with simple shell scripts to switch forth/back 
> the default route when the ppp interface goes down or up. To get this work 
> well, ppp has to be cofigured to check the link "health".
> 
> NetBSD allows many standard routing protocols which - in parts - may provide 
> similiar solutions.
> 
> One problem is, that all these solutions does not recognize if your ISP has 
> some "uplink" down, because it only checks the health of the DSL connection. 
> In such cases your failover would not switch as you might want that. Some ppl 
> write scripts which ping some "highly available" IP somewhere in the internet 
> to check if "internet connectivity" really works and let switch over by shell 
> if a ping series goes to nirvana.

	I have done this kind of script on a Linux box. But I don't know how
write these scripts on a NetBSD server. For example, how can I ping a
server on WAN side through 192.168.15.19 gateway and with 192.168.15.20
default route ? Of course, I could add a special route to contact this
server, but is it possible without adding a sepcial route ?

	Best regards,

	JKB