No need to thank me ;)

Ron
--
Ronald L. Johnson
[email protected]
628.202.2396


On Tue, Jan 19, 2021 at 1:44 AM Dan Mahoney (Gushi) <[email protected]>
wrote:

> On Mon, 18 Jan 2021, Ronald L. Johnson wrote:
>
> > If that's the case and you have this huge worldwide presence and
> > millions of customers, why then are you not using some of that hard
> > earned cash to use proper commercial products? Just seems very odd to
> > me...
>
> We have a couple dozen users on our SIP server.  We're a small software
> company with developers around the world using their own devices.  That's
> the userbase of this system.  I never said millions of customers.
>
> SIP isn't our main business at all, but we do know what we're doing with
> it.  This kind of functionality is not something that asterisk builds in,
> and compromising a SIP server is considered a high-value target.
>
> That said, I'm quickly coming to two conclusions:
>
> 1) Fail2Ban has trouble scaling to this type of load.
>
> 2) I suspect I've gotten all the help I'm likely to get here.
>
> I know my regexes work, as confirmed by the fail2ban tools.  I've
> replicated the problem more than once.  I've been accused of being a
> spammer and then had our business decisions questioned.
>
> I'm happy to keep working with a developer, offer real time traffic pcaps
> or whatnot, but for obvious reasons, I don't want to post hostnames or ip
> addresses to a public list.
>
> I thank you all for it and wish you all a safe 2021.
>
> -Dan
>
> >
> > Ron
> > --
> > Ronald L. Johnson
> > [email protected]
> > 628.202.2396
> >
> >
> > On Sun, Jan 17, 2021 at 11:23 PM Dan Mahoney (Gushi) <[email protected]>
> wrote:
> >       On Sun, 17 Jan 2021, Ron Johnson wrote:
> >
> >       >
> >       > Sounds like we’re trying to help someone fix a spamming sip
> server. Should we be doing this? Forgive me if I’m wrong.
> >
> >       *sigh*
> >
> >       No, you're trying to help someone fix Fail2Ban on a SIP server
> that must
> >       be open for registrations from the entire world because our
> employees do
> >       not always use a corporate VPN.  Additionally, for historic
> reasons,
> >       people in our community are occasionally called via their direct
> >       sip://uri.  (Less so than years ago, but we were part of something
> called
> >       INOC-DBA which was sort of a community-based sip pool).
> >
> >       What that means is you'll get two different classes of things:
> >
> >       1) Lots of fake registrations, which fail.
> >
> >       [2021-01-17 18:54:56] NOTICE[828]: chan_sip.c:28499
> >       handle_request_register: Registration from
> >       '"2001"<sip:[email protected]>'
> >       failed for '82.205.10.23:29868' - Wrong password
> >
> >       [2021-01-17 18:55:40] NOTICE[828]: chan_sip.c:28499
> >       handle_request_register: Registration from
> '<sip:[email protected]>'
> >       failed for '212.129.42.78:58728' - Wrong password
> >
> >       2) Lots of unregistered calls, which hope that your dialplan is
> woefully
> >       misconfigured and will allow those calls anyway, which will also
> fail.
> >       (If it had ever "worked" we would know because our long distance
> accounts
> >       would be depleted, which have their own (financial) rate-limits and
> >       alerting on them.
> >
> >       [2021-01-17 19:05:04] NOTICE[828][C-000717b2]: chan_sip.c:26273
> >       handle_request_invite: Call from '' (192.40.59.239:57878) to
> extension
> >       '111111011972595725668' rejected because extension not found in
> context
> >       'untrustedsip'.
> >
> >       [2021-01-17 19:01:45] NOTICE[828][C-000717b1]: chan_sip.c:26273
> >       handle_request_invite: Call from '' (62.210.100.129:5071) to
> extension
> >       '0041215080459' rejected because extension not found in context
> >       'untrustedsip'.
> >
> >       The thing is, when you're in the asterisk console trying to debug a
> >       non-working extension, all the above scrolls past so quickly that
> it makes
> >       things impossible to use.
> >
> >       Additionally, denying these requests and sending back a 401
> response is
> >       traffic we'd rather not generate because SIP is UDP, so it *could*
> be
> >       spoofed and be a reflection attack. (It's probably not, since that
> would
> >       make the calls not work).
> >
> >
> >       >
> >       >
> >       >
> >       > Ron
> >       >
> >       >
> >       >
> >       >
> >       >
> >       > Sent from Mail for Windows 10
> >       >
> >       >
> >       >
> >       > From: Dan Mahoney (Gushi)
> >       > Sent: Sunday, January 17, 2021 11:24 AM
> >       > To: James Moe
> >       > Cc: [email protected]
> >       > Subject: Re: [Fail2ban-users] Fail2Ban finding but not blocking.
> >       >
> >       >
> >       >
> >       > On Sun, 17 Jan 2021, James Moe via Fail2ban-users wrote:
> >       >
> >       >
> >       >
> >       > > On 1/14/21 8:12 AM, Dan Mahoney (Gushi) wrote:
> >       >
> >       > >
> >       >
> >       > >> We have a regex that "matches" but I watch fail2ban.log with
> "tail
> >       >
> >       > >> -F" and I watch match and match and match
> >       >
> >       > >> and not ban.
> >       >
> >       > >>
> >       >
> >       > >  I see a similar pattern here for this reason: When f2b scans
> a log file it
> >       >
> >       > > finds multiple log entries of an attack, and lists them all as
> an INFO. Then at
> >       >
> >       > > the end of the scan, the IP is banned.
> >       >
> >       > >  Your f2b log shows f2b was restarted before the scan was
> finished. After the
> >       >
> >       > > restart, the scan continued and the IP was ultimately banned.
> >       >
> >       >
> >       >
> >       > So, what ends the scan?
> >       >
> >       >
> >       >
> >       > From what you're saying it sounds like fail2ban has to hit the
> EOF marker,
> >       >
> >       > which would imply as long as one could fill the logs faster than
> fail2ban
> >       >
> >       > can count, you can evade a block.
> >       >
> >       >
> >       >
> >       > These are often very fast scans, attempts to push dozens or
> hundreds of
> >       >
> >       > registrations/calls through our asterisk server all at once.
> (Yes, it has
> >       >
> >       > to be public for historic reasons -- we have a global userbase).
> >       >
> >       >
> >       >
> >       > Note: I watched the logs for at least ten seconds waiting for
> something to
> >       >
> >       > happen, with screenfuls of the same ip not blocking.  I gave it
> a good
> >       >
> >       > shot to catch itself before restarting.
> >       >
> >       >
> >       >
> >       > -Dan
> >       >
> >       >
> >       >
> >       > --
> >       >
> >       >
> >       >
> >       > --------Dan Mahoney--------
> >       >
> >       > Techie,  Sysadmin,  WebGeek
> >       >
> >       > Gushi on efnet/undernet IRC
> >       >
> >       > FB:  fb.com/DanielMahoneyIV
> >       >
> >       > LI:   linkedin.com/in/gushi
> >       >
> >       > Site:  http://www.gushi.org
> >       >
> >       > ---------------------------
> >       >
> >       >
> >       >
> >       >
> >       >
> >       >
> >       >
> >       > _______________________________________________
> >       >
> >       > Fail2ban-users mailing list
> >       >
> >       > [email protected]
> >       >
> >       > https://lists.sourceforge.net/lists/listinfo/fail2ban-users
> >       >
> >       >
> >       >
> >       >
> >       >
> >
> >       --
> >
> >       <Belldandy> ha. you have not met me.
> >       <BaldDwarf> ha. but i have sene pictures
> >       <Belldandy> thanks but uh.,
> >       <BaldDwarf> seen dammit! SEEN!
> >       <Gushi> I don't know who dammit! is.
> >       <Belldandy> so anyway
> >
> >       -Undernet #reboot, October 2nd, 2000, 3AM
> >
> >       --------Dan Mahoney--------
> >       Techie,  Sysadmin,  WebGeek
> >       Gushi on efnet/undernet IRC
> >       FB:  fb.com/DanielMahoneyIV
> >       LI:   linkedin.com/in/gushi
> >       Site:  http://www.gushi.org
> >       ---------------------------
> >
> >
> >
>
> --
>
> "If you need web space, give him a hard drive.  If you need to do
> something really heavy, build him a computer."
>
> -Ilzarion, late friday night
>
> --------Dan Mahoney--------
> Techie,  Sysadmin,  WebGeek
> Gushi on efnet/undernet IRC
> FB:  fb.com/DanielMahoneyIV
> LI:   linkedin.com/in/gushi
> Site:  http://www.gushi.org
> ---------------------------
>
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