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From: Steve Simon <steve@quintile.net>
To: 9front@9front.org
Subject: Re: [9front] dns tools
Date: Tue, 31 Jan 2023 07:58:39 +0000	[thread overview]
Message-ID: <7C2D6F4D-43C7-4414-AB27-355251682286@quintile.net> (raw)
In-Reply-To: <8D9D9A9B7E2B716DB457719182D5271D@thinktankworkspaces.com>


there is also greylisting in smtpd which can put off some bots.

if its a small selection of ip addresses, smtpd can be told to silently drop ip connections from these.

i have a modified ratfs which checks the remote dns name and rejects based on a pattern match. i also added a hex digit pattern (%). the idea was to reject all email from rdns names like:

      line.%.%-adsl.verizon-west.com

this helped with everything else, but sadly i have (after about 15 years) given up receiving email on plan9 and use my isp. $work and kids don't leave enough time to fight the good email fight

-Steve

> On 31 Jan 2023, at 6:44 am, william@thinktankworkspaces.com wrote:
> 
> ratfs seems to be working. I'm not getting the mail locally, but they still keep trying
> 
> maat Jan 30 21:37:52 ehlo from 185.24.233.112 as ADMIN
> maat Jan 30 21:37:52 Hung up on 185.24.233.112; claimed to be ADMIN
> maat Jan 30 21:45:59 ehlo from 185.24.233.112 as ADMIN
> maat Jan 30 21:45:59 Hung up on 185.24.233.112; claimed to be ADMIN
> maat Jan 30 21:49:44 ehlo from 81.161.229.226 as WIN-CLJ1B0GQ6JP
> maat Jan 30 21:49:44 Hung up on 81.161.229.226; claimed to be WIN-CLJ1B0GQ6JP
> maat Jan 30 21:54:12 ehlo from 185.24.233.112 as ADMIN
> maat Jan 30 21:54:12 Hung up on 185.24.233.112; claimed to be ADMIN
> 
> I could probably look into scanmail. I might also try blocking from linode, maybe look at some firewall features from
> the provider. 
> 
> Quoth Stanley Lieber <sl@stanleylieber.com>:
>>> On Jan 29, 2023, at 11:14 PM, william@thinktankworkspaces.com wrote:
>>> 
>>> Do we have any firewall tools? I would like to block some connections. 
>>> 
>>> I know you can tweak routing by messing with /net/ipifc/clone
>>> 
>>> Just wanted to know if we have any other ways to block conncetions?
>>> 
>>> 
>>> 
>>> Quoth Stanley Lieber <sl@stanleylieber.com>:
>>>> check out iwhois (documented in the tel man page).
>>>> 
>>>> also: lookman dns.
>>>> 
>>>> the existing tools are fairly manual and rudimentary.
>>>> 
>>>> sl
>> 
>> there’s no generic firewall, but upas has some filtering options. smtpd(8) reads the file /mail/blocked for blocked addresses, and has the -k flag to block ip addresses manually. the validatesender script (called by upas) checks for a spamhaus file at /mail/lib/spamhaus. there are also ratfs(4) and scanmail(8), which provide more complex filtering mechanisms.
>> 
>> sl
>> 
>> 
>> 
> 

      reply	other threads:[~2023-01-31  8:02 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-01-30  1:52 william
2023-01-30  2:10 ` Stanley Lieber
2023-01-30  4:11   ` william
2023-01-30  4:59     ` Stanley Lieber
2023-01-30  5:27       ` Jacob Moody
2023-01-31  6:41       ` william
2023-01-31  7:58         ` Steve Simon [this message]

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