<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class=""><br class=""></div> I have turned on my Mac Firewall and now get the same behavior as Mark.<div class=""><br class=""></div><div class=""> I have the Automatically allow builtin software to receive incoming connections checked So /sbin/ping must not be a builtin software</div><div class=""><br class=""></div><div class=""> I then tried to unblock /sbin/ping from the firewall with <br class=""><div><br class=""></div><div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">sudo /usr/libexec/ApplicationFirewall/socketfilterfw --add /sbin/ping</span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures;" class=""><div style="font-family: Menlo; font-size: 14px; margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">sudo /usr/libexec/ApplicationFirewall/socketfilterfw --unblock /sbin/ping</span></div><div style="font-family: Menlo; font-size: 14px; margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">Incoming connection to the application is permitted </span></div><div style="font-family: Menlo; font-size: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div style="font-family: Menlo; font-size: 14px;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div class="">ping still indicates <span style="font-family: Menlo; font-size: 14px;" class="">Request timeout for icmp_seq 0</span></div><div class=""><span style="font-family: Menlo; font-size: 14px;" class=""><br class=""></span></div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">But</div><div class=""><br class=""></div><div class=""><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">$ /usr/sbin/traceroute `hostname`</span></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">traceroute: Warning: Barrys-MacBook-Pro-3.local has multiple addresses; using 127.0.0.1</span></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class="">traceroute to barrys-macbook-pro-3.local (127.0.0.1), 64 hops max, 52 byte packets</span></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""> 1 localhost (127.0.0.1) 0.539 ms 0.101 ms 0.067 ms</span></div></div><div style="margin: 0px; font-stretch: normal; font-size: 14px; line-height: normal; font-family: Menlo;" class=""><span style="font-variant-ligatures: no-common-ligatures" class=""><br class=""></span></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><span style="font-family: Menlo; font-size: 14px; font-variant-ligatures: no-common-ligatures;" class=""><span style="font-family: Helvetica; font-size: 18px;" class="">works with the Firewall on. In fact </span></span>traceroute works with the Automatically allow builtin software to receive incoming connections NOT checked. </div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class="">traceroute also fails like ping when vpn is turned on for my Mac.</div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class="">Mark,</div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""> You need not bother with the lists of tasks I sent you. Thanks</div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""> Barry</div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""><br class=""></div><div style="margin: 0px; font-stretch: normal; line-height: normal;" class=""> </div></span></div><blockquote type="cite" class=""><div class="">On Sep 18, 2020, at 9:28 AM, Satish Balay via petsc-users <<a href="mailto:petsc-users@mcs.anl.gov" class="">petsc-users@mcs.anl.gov</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><blockquote type="cite" class=""><blockquote type="cite" class=""><blockquote type="cite" class="">07:41 master *= ~/Codes/petsc$ ping -c 2 MarksMac-302.local<br class="">PING marksmac-302.local (127.0.0.1): 56 data bytes<br class=""></blockquote></blockquote></blockquote><br class="">So it is resolving MarksMac-302.local as 127.0.0.1 - but ping is not responding?<br class=""><br class="">I know some machines don't respond to external ping [and firewalls can block it] but don't really know if they always respond to internal ping or not.<br class=""><br class="">If some machines don't respond to internal ping - then we can't use ping test in configure [it will create false negatives - as in this case]<br class=""><br class=""><br class="">Mark, can you remove the line that you added to /etc/hosts - i.e:<br class=""><br class="">127.0.0.1 MarksMac-302.local<br class=""><br class="">And now rerun MPI tests. Do they work or fail?<br class=""><br class="">[this is to check if this test is a false positive on your machine]<br class=""><br class="">Satish<br class=""><br class=""><br class="">On Fri, 18 Sep 2020, Mark Adams wrote:<br class=""><br class=""><blockquote type="cite" class="">On Fri, Sep 18, 2020 at 7:51 AM Matthew Knepley <<a href="mailto:knepley@gmail.com" class="">knepley@gmail.com</a>> wrote:<br class=""><br class=""><blockquote type="cite" class="">On Fri, Sep 18, 2020 at 7:46 AM Mark Adams <<a href="mailto:mfadams@lbl.gov" class="">mfadams@lbl.gov</a>> wrote:<br class=""><br class=""><blockquote type="cite" class="">Oh you did not change my hostname:<br class=""><br class="">07:37 master *= ~/Codes/petsc$ hostname<br class="">MarksMac-302.local<br class="">07:41 master *= ~/Codes/petsc$ ping -c 2 MarksMac-302.local<br class="">PING marksmac-302.local (127.0.0.1): 56 data bytes<br class="">Request timeout for icmp_seq 0<br class=""><br class="">--- marksmac-302.local ping statistics ---<br class="">2 packets transmitted, 0 packets received, 100.0% packet loss<br class="">07:42 2 master *= ~/Codes/petsc$<br class=""><br class=""></blockquote><br class="">This does not make sense to me. You have<br class=""><br class=""> 127.0.0.1 MarksMac-302.local<br class=""><br class="">in /etc/hosts,<br class=""><br class=""></blockquote><br class="">09:07 ~/.ssh$ cat /etc/hosts<br class="">##<br class=""># Host Database<br class="">#<br class=""># localhost is used to configure the loopback interface<br class=""># when the system is booting. Do not change this entry.<br class="">##<br class="">127.0.0.1 localhost<br class="">255.255.255.255 broadcasthost<br class="">127.0.0.1 MarksMac-5.local<br class="">127.0.0.1 243.124.240.10.in-addr.arpa.private.cam.ac.uk<br class="">127.0.0.1 MarksMac-302.local<br class="">09:07 ~/.ssh$<br class=""><br class=""><br class=""><br class=""><br class=""><br class=""><blockquote type="cite" class="">but you cannot resolve that name?<br class=""><br class=""> Matt<br class=""><br class=""><br class=""><blockquote type="cite" class="">BTW, I used to get messages about some network issue and 'changing host<br class="">name to MarksMac-[x+1].local'. That is, the original hostname<br class="">was MarksMac.local, then I got a message about changing<br class="">to MarksMac-1.local, etc. I have not seen these messages for months but<br class="">apparently this process has continued unabated.<br class=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class=""><br class="">On Thu, Sep 17, 2020 at 11:10 PM Satish Balay via petsc-users <<br class=""><a href="mailto:petsc-users@mcs.anl.gov" class="">petsc-users@mcs.anl.gov</a>> wrote:<br class=""><br class=""><blockquote type="cite" class="">On Thu, 17 Sep 2020, Matthew Knepley wrote:<br class=""><br class=""><blockquote type="cite" class="">On Thu, Sep 17, 2020 at 8:33 PM Barry Smith <<a href="mailto:bsmith@petsc.dev" class="">bsmith@petsc.dev</a>> wrote:<br class=""><br class=""><blockquote type="cite" class=""><blockquote type="cite" class="">On Sep 17, 2020, at 4:59 PM, Satish Balay via petsc-users <<br class=""></blockquote><a href="mailto:petsc-users@mcs.anl.gov" class="">petsc-users@mcs.anl.gov</a>> wrote:<br class=""><blockquote type="cite" class=""><br class="">Here is a fix:<br class=""><br class="">echo 127.0.0.1 `hostname` | sudo tee -a /etc/hosts<br class=""></blockquote><br class=""> Satish,<br class=""><br class=""> I don't think you want to be doing this on a Mac (on anything?)<br class=""></blockquote></blockquote>On a<br class=""><blockquote type="cite" class=""><blockquote type="cite" class="">Mac based on the network configuration etc as it boots up and as<br class=""></blockquote></blockquote>networks<br class=""><blockquote type="cite" class=""><blockquote type="cite" class="">are accessible or not (wi-fi) it determines what hostname should be,<br class=""></blockquote></blockquote>one<br class=""><blockquote type="cite" class=""><blockquote type="cite" class="">should never being hardwiring it to some value.<br class=""><br class=""></blockquote><br class="">Satish is just naming the loopback interface. I did this on all my<br class=""></blockquote>former<br class=""><blockquote type="cite" class="">Macs.<br class=""></blockquote><br class=""><br class="">Yes - this doesn't change the hostname. Its just adding an entry for<br class="">gethostbyname - for current hostname.<br class=""><br class=""><blockquote type="cite" class=""><blockquote type="cite" class=""><blockquote type="cite" class=""><br class=""></blockquote></blockquote></blockquote>127.0.0.1 MarksMac-302.local<br class=""><<<<br class=""><br class="">Sure - its best to not do this when one has a proper IP name [like<br class=""><a href="http://foo.mcs.anl.gov" class="">foo.mcs.anl.gov</a>] - but its useful when one has a hostname like<br class="">"MarksMac-302.local" -that is not DNS resolvable<br class=""><br class="">Even if the machine is moved to a different network with a different<br class="">name - the current entry won't cause problems [but will need another entry<br class="">for the new host name - if this new name is also not DNS resolvable]<br class=""><br class="">Its likely this file is a generated file on macos - so might get reset<br class="">on reboot - or some network change? [if this is the case - the change won't<br class="">be permanent]<br class=""><br class=""><br class="">Satish<br class=""><br class=""></blockquote><br class=""></blockquote><br class="">--<br class="">What most experimenters take for granted before they begin their<br class="">experiments is infinitely more interesting than any results to which their<br class="">experiments lead.<br class="">-- Norbert Wiener<br class=""><br class=""><a href="https://www.cse.buffalo.edu/~knepley/" class="">https://www.cse.buffalo.edu/~knepley/</a><br class=""><http://www.cse.buffalo.edu/~knepley/><br class=""><br class=""></blockquote><br class=""></blockquote><br class=""></div></div></blockquote></div><br class=""></div></body></html>