override entries change network prefix length

override entries change network prefix length

[Peter Müller]

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Hello Michael,
hello location folks (CC'ed),

finally having some spare time to spend on ${things}, I thought working on #11754, #12594 and #12595
might be a good idea to improve the results of our location database. :-)

Since #11754 and #12594 involve something like automated overrides to fetched RIR data, I recently noticed
adding overrides is changing the displayed network length in a "location lookup" output:

> [root(a)maverick ~]# location lookup 176.10.99.192
> 176.10.99.192:
>   Network                 : 176.10.99.192/27
>   Country                 : Switzerland
>   Autonomous System       : AS51395 - Datasource AG
>   Anonymous Proxy         : yes

176.10.99.192 is part of 176.10.96.0/19, which is announced as such by AS51395, hence the output is
misleading. A better result would be to display the original size of a BGP announcement, adding some
flags if needed without stripping down the IP network size to the override.

This is a minor issue as far as I am concerned, but before I create code that generates overrides en
masse, I would like to discuss whether or not it is a good idea to keep the current behaviour.

Thanks, and best regards,
Peter Müller

Re: override entries change network prefix length

[Michael Tremer]

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Hello,

> On 28 Mar 2021, at 07:43, Peter Müller <peter.mueller(a)ipfire.org> wrote:
> 
> Hello Michael,
> hello location folks (CC'ed),
> 
> finally having some spare time to spend on ${things}, I thought working on #11754, #12594 and #12595
> might be a good idea to improve the results of our location database. :-)
> 
> Since #11754 and #12594 involve something like automated overrides to fetched RIR data, I recently noticed
> adding overrides is changing the displayed network length in a "location lookup" output:
> 
>> [root(a)maverick ~]# location lookup 176.10.99.192
>> 176.10.99.192:
>>  Network                 : 176.10.99.192/27
>>  Country                 : Switzerland
>>  Autonomous System       : AS51395 - Datasource AG
>>  Anonymous Proxy         : yes
> 
> 176.10.99.192 is part of 176.10.96.0/19, which is announced as such by AS51395, hence the output is
> misleading. A better result would be to display the original size of a BGP announcement, adding some
> flags if needed without stripping down the IP network size to the override.

I do not find this confusing. We are just stating that this IP address belongs to a certain AS. We do not make any statements about any other IP addresses in the same AS or other ones.

If you could query a whole subnet, that would be a different thing.

> This is a minor issue as far as I am concerned, but before I create code that generates overrides en
> masse, I would like to discuss whether or not it is a good idea to keep the current behaviour.

I do not see any problem with this. Did I misunderstand you?

> Thanks, and best regards,
> Peter Müller

-Michael