Re: Multi-Networking in Linux - Multiple Subnets

On 2026-07-31 13:46, The Natural Philosopher wrote:
> On 31/07/2026 12:38, Carlos E. R. wrote:
>> On 2026-07-30 18:43, Marc Haber wrote:
>>> "Carlos E. R." <[email protected]> wrote:
>>>> On 2026-07-30 13:42, Marc Haber wrote:
>>>>> "Carlos E. R." <[email protected]> wrote:
>>>>>> eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
>>>>>>           inet 192.168.2.9  netmask 255.255.0.0  broadcast 
>>>>>> 192.168.255.255
>>>>>
>>>>> Using the entire 192.168.0.0/16 range for a single home network is a
>>>>> sure sign of a person not knowing too much about networking or an
>>>>> incompetent ISP.
>>>>
>>>> The ISP configures the router so that it is mandatory to use
>>>> 192.168.1.*, and they take a good chunk of it for their own usage. I
>>>> have no recourse but using this non standard network. I use 192.168.2
>>>> for dhcp assignments.
>>>
>>> With a /16 Netmask, covering the entire 192.168 RFC 1918 range, as if
>>> we have plenty of IPv4 addresses?
>>>
>>> Please, let me see that ISPs customer documentation. They do have it
>>> online, don't they? I'm familiar with that industry for nearly 30
>>> years and have never seen a setup like that. It sounds so brain-dead
>>> that my first idea was that you haven't understood.
>>
>> There is no documentation. They keep it secret. What is known is by 
>> reverse engineering.
>>
> Indeed. One of the reasons I hate using mobile phones as routers. 
> Arbitrary and strange IP addresses behind massive firewalls I don't 
> control...
> 

Well, this on is fibre. It is Movistar in Spain. And they are starting 
to "fine" people that use their own optical router. The EU can be 
fucked. Not fine, they simply cancel service.

Source:

<https://bandaancha.eu/articulos/aviso-excepcional-telefonica-conectan-11821>

     *Telefónica has issued an ultimatum to those connecting 
non-official equipment to its fibre network. They must either return 
their router or risk losing their service.*

     The freedom to connect one’s own equipment directly to Movistar’s 
fibre network is coming to an end. Movistar is sending a warning to 
users who do not use its official equipment, notifying them of a drastic 
measure: they will lose their connection if they do not return the 
original equipment.


-- 
Cheers,
        Carlos E.R.
        ES🇪🇸, EU🇪🇺;