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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple style='word-wrap:break-word'><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt'>Funny that. We once ran into an issue suddenly on a server. When we tracked it down it was found we had the wrong netmask for the VLAN on our affected server.<br><br>The odd thing was when I found it I could see it had been incorrect ever since we’d moved to a new data center months earlier (and presumably was at the old data center). Though changing it resolved the issue no one could ever explain why it had “suddenly” become a problem given that it had run misconfigured for so long. I suspect the network or security admins made a tweak of some sort on discovering a misconfiguration on their end. Doing that would be OK but should have been done via a change control. Almost always, finding the solution to a problem starts with the question: “What changed?”<br><br>Of course we immediately checked our other servers to be sure none were configured with incorrect netmasks or gateways.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt'><o:p> </o:p></span></p><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'>From:</span></b><span style='font-size:11.0pt;font-family:"Calibri",sans-serif'> Boris Borisov <bugyatl@gmail.com> <br><b>Sent:</b> Monday, November 18, 2024 12:44 PM<br><b>To:</b> Atlanta Linux Enthusiasts <ale@ale.org><br><b>Cc:</b> JEFFREY LIGHTNER <jc.lightner@comcast.net><br><b>Subject:</b> Re: [ale] OT: dumb question<o:p></o:p></span></p></div><p class=MsoNormal><o:p> </o:p></p><div><p>Turns out the switch port was pass-through to the wrong VLAN.<o:p></o:p></p><p>Likely for me I've got the proper guy on the phone today.<o:p></o:p></p></div><p class=MsoNormal><o:p> </o:p></p><div><div><p class=MsoNormal>On Fri, Nov 15, 2024, 18:44 Jeff Lightner via Ale <<a href="mailto:ale@ale.org" target="_blank">ale@ale.org</a>> wrote:<o:p></o:p></p></div><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in'><p class=MsoNormal>Often ping is disabled on gateways to prevent DoS attacks. If you need to<br>ping it for monitoring purposes you might be able to get the admin to<br>whitelist the IP from which you're attempting the ping.<br><br>-----Original Message-----<br>From: Ale <<a href="mailto:ale-bounces@ale.org" target="_blank">ale-bounces@ale.org</a>> On Behalf Of Derek Atkins via Ale<br>Sent: Friday, November 15, 2024 2:58 PM<br>To: Atlanta Linux Enthusiasts <<a href="mailto:ale@ale.org" target="_blank">ale@ale.org</a>><br>Cc: Derek Atkins <<a href="mailto:derek@ihtfp.com" target="_blank">derek@ihtfp.com</a>><br>Subject: Re: [ale] OT: dumb question<br><br>Yeah, some gateways do not respond to a ping.<br>Do you get an IP Address? A Route?<br>Try ping (or better yet, mtr) to 8.8.8.8<br><br>-derek<br><br>On Fri, November 15, 2024 2:38 pm, Boris Borisov via Ale wrote:<br>> I never dealt with network switches so there.<br>><br>> I have a device set on small network segment connected to a switch <br>> that I don't have control to.<br>><br>> I cannot ping the gateway on that segment.<br>><br>> Is there any reason/possibility gateway to not respond on ping?<br>> _______________________________________________<br>> Ale mailing list<br>> <a href="mailto:Ale@ale.org" target="_blank">Ale@ale.org</a><br>> <a href="https://mail.ale.org/mailman/listinfo/ale" target="_blank">https://mail.ale.org/mailman/listinfo/ale</a><br>> See JOBS, ANNOUNCE and SCHOOLS lists at <br>> <a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><br>><br><br><br>-- <br> Derek Atkins 617-623-3745<br> <a href="mailto:derek@ihtfp.com" target="_blank">derek@ihtfp.com</a> <a href="http://www.ihtfp.com" target="_blank">www.ihtfp.com</a><br> Computer and Internet Security Consultant<br><br>_______________________________________________<br>Ale mailing list<br><a href="mailto:Ale@ale.org" target="_blank">Ale@ale.org</a><br><a href="https://mail.ale.org/mailman/listinfo/ale" target="_blank">https://mail.ale.org/mailman/listinfo/ale</a><br>See JOBS, ANNOUNCE and SCHOOLS lists at<br><a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><br><br>_______________________________________________<br>Ale mailing list<br><a href="mailto:Ale@ale.org" target="_blank">Ale@ale.org</a><br><a href="https://mail.ale.org/mailman/listinfo/ale" target="_blank">https://mail.ale.org/mailman/listinfo/ale</a><br>See JOBS, ANNOUNCE and SCHOOLS lists at<br><a href="http://mail.ale.org/mailman/listinfo" target="_blank">http://mail.ale.org/mailman/listinfo</a><o:p></o:p></p></blockquote></div></div></body></html>