Internet tools, Web Server (apache) and DNS (bind) on Apple using Homebrew

Online Internet Test Tools to check Servers, Internet Protocols and Implementations


BREW, XCODE and BBEdit command line tools




On Intel architecture:

  • /bin/bash -c "$(curl -fsSL"
  • echo 'export PATH=/usr/local/bin:/usr/local/sbin:$PATH' >> ~/.zshrc
  • sudo install -d -o $(whoami) -g admin /usr/local/Frameworks

On Apple M architecture:

  • /bin/bash -c "$(curl -fsSL"
  • echo 'eval "$(/opt/homebrew/bin/brew shellenv)"' >> /Users/$(whoami)/.zprofile
  • eval "$(/opt/homebrew/bin/brew shellenv)"
  • sudo install -d -o $(whoami) -g admin /opt/homebrew/Frameworks

Some in newer MacOS missing libs:

  • brew install openssl

Nowadays this automatically installs Apples command line tools. If not then:

  • xcode-select --install

If needed to re-install command tools do this command first to remove previous tools:

  • sudo rm -rf /Library/Developer/CommandLineTools

Install BBEdit from

Start BBEdit and set up its command line tools under the BBEdit menu. For more information see:

For multi user HomeBrew see:
Rather than keep switching the owner to whomever I’m logged in as, or just having one user take care of all brew update/upgrades, you just have to ‘tweak’ the instructions and grant ownership to the `admin` group. A quick sudo chgrp -R admin $(brew --prefix) will switch all Brew folders to the admin group. You will get an error trying to update /usr/local/, this is fine and doesn’t cause issues. Then a sudo chmod -R g+rwX $(brew --prefix) to update the permissions on the same folders and you’re done. Obviously this now means that any admin can use Homebrew but they are admins after all.:

Be careful, if there are certificates (certbot) or other installations like mailserver, this ownership/privilege change may interrupt those services.
  • sudo chgrp -R admin $(brew --prefix)
  • sudo chmod -R g+rwX $(brew --prefix)


Check version and installation:

  • brew doctor
  • brew --version
If needed to correct permissions (Be careful, if there are certificates (certbot) or other installations like mailserver, this ownership/privilege change may interrupt those services.):
  • sudo chown -R "$USER":admin /usr/local
  • sudo chown -R "$USER":admin /Library/Caches/Homebrew

You may get an error warning: homebrew-core is a shallow clone. Explanation: This restriction has been made on GitHub's request because updating shallow clones is an extremely expensive operation due to the tree layout and traffic of Homebrew/homebrew-core and Homebrew/homebrew-cask. We don't do this for you automatically to avoid repeatedly performing an expensive unshallow operation in CI systems (which should instead be fixed to not use shallow clones). Sorry for the inconvenience! Therefore, to `brew update`, first run:

  • git -C /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core fetch --unshallow

To remove brew alltogether:

  • sudo brew services stop --all
  • /bin/bash -c "$(curl -fsSL"


To upgrade all installed programs to newest version:

  • brew update
  • brew upgrade
  • brew cleanup
  • brew services list
  • sudo brew services restart --all



  • brew install httpd
  • sudo brew services start httpd


In a separate window show dynamically the tail of the error and access logfiles:

  • tail -n 200 -f /usr/local/var/log/httpd/error_log
  • tail -n 200 -f /usr/local/var/log/httpd/access_log
If install has problems because of previous versions:
  • sudo launchctl unload -w /System/Library/LaunchDaemons/org.apache.httpd.plist
  • sudo apachectl stop
  • sudo brew services restart httpd

To check what a site is running, if not installed install lynx first:

  • brew install lynx
  • lynx -dump -head <website> | grep ^Server

Check if deamon is running:

  • ps -aef | grep httpd
To get setup paths:
  • sudo apachectl -S
Test conf files, must be with sudo to test certificates:
  • sudo apachectl configtest


To restart httpd:

  • sudo brew services restart httpd
  • sudo apachectl stop
  • sudo apachectl -k restart

HTTPD config edits HTTP2, headers, userdirs, proxy


HTTPD config basic edits:

  • bbedit /usr/local/etc/httpd/httpd.conf
  1. Listen 8080 => Listen 80
  2. enable ==> LoadModule deflate_module lib/httpd/modules/
  3. enable ==> LoadModule rewrite_module lib/httpd/modules/
  4. ServerAdmin root@localhost
  5. #ServerName ==> ServerName localhost:80
  6. enable ==> Include /usr/local/etc/httpd/extra/httpd-autoindex.conf

HTTPD config edits to enable http2

  • bbedit /usr/local/etc/httpd/httpd.conf
  1. disable ===> #LoadModule mpm_prefork_module lib/httpd/modules/
  2. enable ===> LoadModule mpm_event_module lib/httpd/modules/
  3. enable ===> LoadModule http2_module lib/httpd/modules/
  4. add ===> Protocols h2 h2c http/1.1

Enable full filename display in case of directory index:

  • bbedit /usr/local/etc/httpd/extra/httpd-autoindex.conf

add NameWidth=* to the line IndexOptions FancyIndexing HTMLTable VersionSort

  1. ===> IndexOptions FancyIndexing HTMLTable VersionSort NameWidth=*


In httpd.conf:
  • bbedit /usr/local/etc/httpd/httpd.conf
  1. enable ==> LoadModule userdir_module lib/httpd/modules/
  2. enable ==> Include /usr/local/etc/httpd/extra/httpd-userdir.conf
  • bbedit /usr/local/etc/httpd/extra/httpd-userdir.conf
Change public_html into Sites (NOTE: 2 places!)

Optionally to enable (reverse) proxies.


In httpd.conf:

  • bbedit /usr/local/etc/httpd/httpd.conf
  1. enable ==> LoadModule proxy_module lib/httpd/modules/
  2. enable ==> LoadModule proxy_http_module lib/httpd/modules/
Then for port based in case of http:
  • bbedit /usr/local/etc/httpd/extra/httpd-vhosts.conf
  • Listen 12345
    <VirtualHost *:12345>
        ProxyPass "/" ""
        ProxyPassReverse "/" ""

  • Or for https:// in the ssl vhost file below to embed traffic in ssl:
    Listen 12345
    <VirtualHost *:12345>
        ProxyPass "/" "" retry=1 acquire=3000 timeout=10 Keepalive=On
        ProxyPassReverse "/" ""
        SSLEngine on
        SSLCertificateFile /etc/letsencrypt/live/
        SSLCertificateKeyFile /etc/letsencrypt/live/



HTML default header


A good web pages header for .html files:

  <meta http-equiv="content-type" content="text/html; charset=windows-1252">
  <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=0.25, maximum-scale=4.0, user-scalable=yes">
  <body style="font-family: Helvetica, Arial, Lucida Bright; color: white; background-color: black;" alink="#FF9900" link="#FFCC66" vlink="#FFFF66">



HTTPD config edits for vhosts


HTTPD config edits enable vhosts:

  • bbedit /usr/local/etc/httpd/httpd.conf
  1. enable ==> LoadModule vhost_alias_module lib/httpd/modules/
  2. enable ==> Include /usr/local/etc/httpd/extra/httpd-vhosts.conf
and for vhosts including a default directory. The default directory is the webroot where all requests go to if there is not a specific webroot for that (sub)domain defined. Therefore, it must be the first in the list. Here an example for edit:
  • bbedit /usr/local/etc/httpd/extra/httpd-vhosts.conf
<VirtualHost *:80>
    DocumentRoot "/usr/local/var/www"
<Directory "/usr/local/var/www">
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted

<VirtualHost *:80>
    DocumentRoot "/Users/example/Sites"
<Directory "/Users/example/Sites">
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted


If you hit permission errors:

  • chmod -R 755 on each Sites directory.
  • chmod +x /Users/<USERNAME>


Let's Encrypt - certbot


  • brew install certbot

NOTE: there are several ways in setting up certbot operations. One way is to use the --apache flag to find and select the (sub)domains and use a running apache server to perform the required letsencrypt challenge. The procedure using --apache fails on some versions of big sur! It seems that on big sur the "sudo brew services start httpd" and "sudo certbot certonly --apache ..." have different effects than previously. The certbot apache module seems unable to find the correct httpd setup information and fails consistently with remarks: "no vhost on port 80" and "no servernames found...". The standalone build-in server also has drawbacks. It requires to stop the webserver as the standalone server also needs to listen to the same ports for the challenge. Another problem is the build in firewall from MacOS. It requires the app to be used in the challenge to be in the list of allowed apps to open and listen on ports. This needs to be correct at renewal or the automatic renewals will fail. It turns out Certbot uses Python for the standalone server, which means that Python must be in the list. That can be a big security risk, and every time brew installs a newer version of the python framework, the firewall needs to be updated. Normally for httpd the system will ask that immediately when the daemon is restarted. In case of the standalone server that message will only (maybe) pop up during the cert renewal when nobody is watching. For completeness here are both procedures.

The procedure using the apache plugin. Note that we give the certificate a constant name "le-cert":

To request the certificates:
  • sudo certbot certonly --apache  --cert-name le-cert
or if one first wants to do a number of test runs for debugging:
  • sudo certbot certonly --apache --cert-name le-cert --staging
for after successful testing forcing a full new certificate:
  • sudo certbot certonly --apache --cert-name le-cert --force-renewal

If pre, post or deploy scripts are needed, those go here:

  • /private/etc/letsencrypt/renewal-hooks

The procedure using the build-in standalone server:

To get the certificate we use the build-in standalone server in certbot and we use certonly to avoid any meddling of the configuration by the certbot plugins. Therefore, we need to stop the apache server, request cert, start server again:
  • sudo certbot certonly --standalone --pre-hook "apachectl stop" --post-hook "apachectl start" --cert-name le-cert -d -d -d -d ...

or if one first wants to do a number of test runs for debugging:

  • sudo certbot certonly --standalone --pre-hook "apachectl stop" --post-hook "apachectl start" --cert-name le-cert -d -d -d -d ... --staging
for after successful testing forcing a full new certificate:
  • sudo certbot certonly --standalone --pre-hook "apachectl stop" --post-hook "apachectl start" --cert-name le-cert -d -d -d -d ... --force-renewal

If pre, post or deploy scripts are needed, those go here:

  • /private/etc/letsencrypt/renewal-hooks

For setup of renewal which is identical in both case:
  • sudo certbot renew

We have to make a launchd plist, see:

However, the plist in the above solutions don't not work because the PATH variable of the running deamon is not correct. Therefore, we add an environment variable in the plist that sets the path.

Create plist:

cat >com.letsencrypt.renew.plist <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "">
<plist version="1.0">
  • sudo mv com.letsencrypt.renew.plist /Library/LaunchDaemons/com.letsencrypt.renew.plist
  • sudo chmod 644 /Library/LaunchDaemons/com.letsencrypt.renew.plist
  • sudo chown root:admin /Library/LaunchDaemons/com.letsencrypt.renew.plist
  • sudo launchctl load -w /Library/LaunchDaemons/com.letsencrypt.renew.plist
  • sudo launchctl list | grep -i letsencrypt

If test runs are needed:

  • sudo certbot renew --dry-run

HTTPD edits:

  • bbedit /usr/local/etc/httpd/httpd.conf


LoadModule ssl_module modules/
LoadModule socache_shmcb_module modules/
Include /usr/local/etc/httpd/extra/httpd-ssl.conf

For best security see:

Edit in httpd-ssl.conf:
  • bbedit /usr/local/etc/httpd/extra/httpd-ssl.conf
  1. Make sure these parameters have following values:
    • SSLCipherSuite TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256:
    • SSLProxyCipherSuite TLS_AES_256_GCM_SHA384:TLS_CHACHA20_POLY1305_SHA256:TLS_AES_128_GCM_SHA256:
    • SSLProtocol             -all +TLSv1.2 +TLSv1.3
    • SSLProxyProtocol        -all +TLSv1.2 +TLSv1.3
    • SSLHonorCipherOrder     on
    • SSLSessionTickets       off
    • SSLCompression          off
    • SSLOptions +StrictRequire
    • # Add vhost name to log entries:
    • LogFormat "%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-agent}i\"" vhost_combined
    • LogFormat "%v %h %l %u %t \"%r\" %>s %b" vhost_common
  2. point the certs at the correct places
    • SSLCertificateFile /etc/letsencrypt/live/le-cert/fullchain.pem
    • SSLCertificateKeyFile /etc/letsencrypt/live/le-cert/privkey.pem
  3. change listen 8443 ==> listen 443
  4. replace everything in the virtual host block including #<VirtualHost _default_:8443> and #</VirtualHost> by:

    <VirtualHost *:443>
        DocumentRoot "/usr/local/var/www"
        SSLEngine on

    <VirtualHost *:443>
        DocumentRoot "/Users/example/Sites"
        SSLEngine on
    <Directory "/Users/example/Sites">
        Options Indexes FollowSymLinks
        AllowOverride All
        Require all granted

The vhost edits:

The idea is that all requests that get through on port 80 or with incorrect url's/domain names end up in: "/usr/local/var/www"
and all requests that come in via https and correct domain names go to the correct webroots of those domains. For that purpose a rewrite rule takes care of redirection. This is in httpd-vhosts.conf
I use the following domain construction for

        catches all (sub)domains for which no other webroot is defined is and points to "/usr/local/var/www"
        this goes to the normal webroot of the domain
        also goes to the normal webroot of the domain
        a subdomain of with its own webroot

in httpd-vhosts.conf:

  • bbedit /usr/local/etc/httpd/extra/httpd-vhosts.conf
<VirtualHost *:80>
    DocumentRoot "/usr/local/var/www"
<Directory "/usr/local/var/www">
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted

<VirtualHost *:80>
    DocumentRoot "/usr/local/var/www"
   RewriteEngine on
   RewriteRule ^ https://%{SERVER_NAME}%{REQUEST_URI} [END,NE,R=permanent]

Note that the Directory directive for example and sub1 is moved to the httpd-ssl.conf file. The documentroot is pointing at "/usr/local/var/www", so that if anything gets through, it points at the default webroot. This ensures that if the http-ssl.conf file does not get processed, the secure webroots are not exposed.


  • sudo tail -f -n 400 /var/log/letsencrypt/letsencrypt.log

To list the certificates:

  • sudo certbot certificates

If test runs are needed:

  • sudo certbot renew --dry-run

Some more debugging:

The configuration file is at: /etc/letsencrypt/renewal/


  • sudo certbot renew
  • sudo certbot certificates

HTTP Headers for Security Hardening


NOTE: only after the certs and https are stable! In httpd.conf:
  • bbedit /usr/local/etc/httpd/httpd.conf
  1. enable ==> LoadModule headers_module lib/httpd/modules/
  2. add at the end of the conf file:

    <IfModule headers_module>
      header set Strict-Transport-Security "max-age=31536000; preload"
      header set X-XSS-Protection "1; mode=block"
      header set X-Frame-Options "SAMEORIGIN"
      header set X-Content-Type-Options "nosniff"
      header set Referrer-Policy "same-origin"
      header set Content-Security-Policy "form-action 'self' https:; object-src 'self' https:; frame-ancestors 'self' https:; require-trusted-types-for 'script';"

Some experimental:
#  header set Strict-Transport-Security "max-age=15768000; includeSubDomains; preload"
#  header set Content-Security-Policy "script-src 'self' 'unsafe-inline' 'unsafe-eval'; object-src 'none';  frame-ancestors 'self'; require-trusted-types-for 'script';"




DNS - named, bind and rndc


  • brew install bind
  • rndc-confgen -a

Edit the conf file:

  • bbedit /usr/local/etc/named.conf
Add in the Options section the directory location of zone files, hiding version for security and rate limiting to prevent ddos amplification:

directory "/usr/local/var/named";
version "unknown";
rate-limit {
           responses-per-second 15;
           window 5;
           log-only no;

And create the zone files in:

  • /usr/local/var/named/
Start bind:
  • sudo brew services start bind


First set up a separate window with tail of logging:

  • tail -f -n 40 /usr/local/var/log/named/named.log

Some checks:

  • rndc status
  • named-checkconf -z /usr/local/etc/bind/named.conf
  • host -t ns


  • rndc sync -clean
  • rndc reload
  • sudo brew services restart bind
  • sudo brew services stop bind

If the server for the domain gets a new ip address:

  • on the master server in /usr/local/etc/named.conf
    • change ip address if needed for primary or secondary server entries
    • change ip address in reverse pointer record entry
  • on the master server in /usr/local/var/named
    • in all relevant zone files change the ip addresses
    • also in those zone files increase the SOA serial numbers
    • refresh the bind server with a bind restart or rndc reload
  • at the dns registrar update the glue records
  • at each of the secondary name servers in /usr/local/etc/named.conf
    • change the appropriate ip addresses to the new values
    • refresh the bind server with a bind restart or rndc reload
  • request your ISP to update the reverse pointer for the ip addresses.



Based on: The location and naming structure used for the zone files is:
  • The master zone files: edit those to change records, etc.
    • /usr/local/var/named/
  • The keys:
    • /usr/local/var/named/keys/
  • Bind can automatically sign and will produce intermediate files in the same directory as the zone files.
  • mkdir /usr/local/var/named/keys

Then we need to once generate the key for each zone file on the master DNS server. That can be done with the following commands:

  • dnssec-keygen -3 -a ECDSAP256SHA256 -K /usr/local/var/named/keys/
  • dnssec-keygen -3 -a ECDSAP256SHA256 -f KSK -K /usr/local/var/named/keys/

Enable DNSSEC in named.conf by adding the following configuration directives inside options{ }:

  • bbedit  /usr/local/etc/named.conf
in the main options add:

key-directory "/usr/local/var/named/keys";

in each of the to be signed signed zones add:

    dnssec-policy default;
    inline-signing yes;

Restart bind to sign the zones and load them in master and slaves:
  • sudo brew services restart bind

Now we need the Delegation Signing records to supply to the parent zone manager. Note, some parent zone managers require the public key and generate the DS themselves. For the DS use dig and dnssec-dsfromkey using a SHA-256 algorithm:

  • dig @ dnskey | dnssec-dsfromkey -2 -f -

For the key alone:

  • dig @ dnskey +multiline


Check if for the DNSKEY record using dig on the same server.
  • dig DNSKEY @localhost +multiline
Check for the presence of RRSIG records.
  • dig A @localhost +noadditional +dnssec +multiline
Check DS records:
  • dig +trace +noadditional DS @ | grep DS




Zone file specials examples on MX, DMARC, SPF, CAA

This are essential additions to zonefiles to express policy on mail handling and security.
If your domain does not handle mail, a Null MX" No Service Resource Record for Domains That Accept No Mail expresses that in DNS. See


  •  @              IN MX      10


SPF (Sender Policy framework) record to indicate where email from this domain is approved to come from:

  • @              IN TXT     "v=spf1 a mx -all"
SPF record to indicate where no email senders approved:
  • @              IN TXT     "v=spf1 -all"


r=relaxed, s=strict

  • _dmarc      IN TXT     "v=DMARC1; p=none; pct=100; aspf=r; adkim=r;"

Strict with spf and dkim:

  • _dmarc      IN TXT     "v=DMARC1; p=quarantine; pct=100; aspf=s; adkim=s;"


CAA (Certificate Authority Authorized) advertises via DNS what CA is used by the domain. For LetsEncrypt:
  • @              IN CAA     128 issue ""





Work in progress. Let's Encrypt makes that it needs to be renewed every 3 months, or needs an adapted server certificate. Based on:

  4. Van Kruyt:
The steps using [1]:

First check if the intermediate certificate of your cert provider changed recently. If so, you may want to have several hashed signatures in your DANE RRSET.
  • study the current and recent issuer names, CN=<name>.

The current intermediate certificates from LetsEncrypt (see: are:






Download the Let’s Encrypt Authority current and upcoming and feed it into openssl to hash the lets-encrypt certs into 2 0 1 TLS records:
  • wget -q -O - | openssl x509 -outform DER | openssl dgst -sha256 -hex | awk '{print "le-ca IN TLSA 2 0 1", $NF}'
  • wget -q -O - | openssl x509 -outform DER | openssl dgst -sha256 -hex | awk '{print "le-ca IN TLSA 2 0 1", $NF}'
  • wget -q -O - | openssl x509 -outform DER | openssl dgst -sha256 -hex | awk '{print "le-ca IN TLSA 2 0 1", $NF}'
  • le-ca IN TLSA 2 0 1 67add1166b020ae61b8f5fc96813c04c2aa589960796865572a3c7e737613dfd
  • le-ca IN TLSA 2 0 1 730c1bdcd85f57ce5dc0bba733e5f1ba5a925b2a771d640a26f7a454224dad3b
  • le-ca IN TLSA 2 0 1 46494e30379059df18be52124305e606fc59070e5b21076ce113954b60517cda
Then put that in the zone file for the different protocols and sub domain names:
_587._tcp.smtp IN CNAME le-ca
_464._tcp.smtp IN CNAME le-ca
_25._tcp.smtp IN CNAME le-ca
_25._tcp IN CNAME le-ca
_443._tcp IN CNAME le-ca
_993._tcp IN CNAME le-ca
_995._tcp IN CNAME le-ca
le-ca IN TLSA 2 0 1 67add1166b020ae61b8f5fc96813c04c2aa589960796865572a3c7e737613dfd
le-ca IN TLSA 2 0 1 730c1bdcd85f57ce5dc0bba733e5f1ba5a925b2a771d640a26f7a454224dad3b
le-ca IN TLSA 2 0 1 46494e30379059df18be52124305e606fc59070e5b21076ce113954b60517cda

Possible rndc commands:
  • rndc reload
  • rndc reconfig





Some thoughts about key management and key rotation:

If one goes for one key pair for several domains, one primary domain and several additional domains, all handled by the same mail server:

Assume a scheme of aliases to the prime domain. Do a number of aliases in each additional domain looking like:

key1._domainkey    IN CNAME
key2._domainkey    IN CNAME
key3._domainkey    IN CNAME
key4._domainkey    IN CNAME

In the prime domain each of them can point to either a retired or previous or current or a potential next key and rotate through those. so:

key1._domainkey IN TXT     "v=DKIM1;k=rsa;p="
key2._domainkey IN TXT     "v=DKIM1;k=rsa;p=MIIBIjANB etc etc etc"
key3._domainkey IN TXT     "v=DKIM1;k=rsa;p=HnYukyhgl etc etc etc"
; key4._domainkey IN TXT ==> to be used next time

Assume 4 key entries like this is enough (one previous retired, one old, one current and one to use next).
The to use next is commented out at the prime domain, so that when it gets used it is filled with key, uncommented  and can populate dns without cache issues. The scheme should be enough but can be expanded, and the scheme can still support individual keys per domain later with more editing.

Based on:


Check for the DKIM record using dig on the same server.

  • dig




For explanation see:
See also RFC 8461

In DNS zone file:



Postfix and Dovecot


Here some options to get a higher score:

Based on:
smtp_tls_security_level = encrypt
smtpd_tls_security_level = encrypt

smtpd_tls_protocols = TLSv1.3, TLSv1.2, !TLSv1.1, !TLSv1, !SSLv2, !SSLv3
smtp_tls_protocols = TLSv1.3, TLSv1.2, !TLSv1.1, !TLSv1, !SSLv2, !SSLv3
smtp_tls_ciphers = medium
smtpd_tls_ciphers = medium
smtpd_tls_mandatory_protocols = TLSv1.3, TLSv1.2, !TLSv1.1, !TLSv1, !SSLv2, !SSLv3
smtp_tls_mandatory_protocols = TLSv1.3, TLSv1.2, !TLSv1.1, !TLSv1, !SSLv2, !SSLv3
smtp_tls_mandatory_ciphers = high
smtpd_tls_mandatory_ciphers = high

smtpd_tls_mandatory_exclude_ciphers = MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
smtpd_tls_exclude_ciphers = MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
smtp_tls_mandatory_exclude_ciphers = MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
smtp_tls_exclude_ciphers = MD5, DES, ADH, RC4, PSD, SRP, 3DES, eNULL, aNULL
tls_preempt_cipherlist = yes
tls_ssl_options = NO_RENEGOTIATION

smtpd_tls_dh2048_param_file = <PATH TO>/dh2048.pem
smtpd_tls_dh1024_param_file = <PATH TO>/dh1024.pem
smtpd_tls_dh512_param_file = <PATH TO>/dh512.pem



SSH on a different port number


This procedure and port numbers come from:

See also:

Procedure using sed to change port 22 in 12345 on server side in file /etc/services in the lines:
  • ssh 22/udp # SSH Remote Login Protocol
  • ssh 22/tcp # SSH Remote Login Protocol
and on client side uncomment and change port in /etc/ssh/ssh_config:
  • #   Port 22

using the commands for server side:

  • sudo sed -i -e 's+ 22/udp+ 12345/udp+g ; s+ 22/tcp+ 12345/tcp+g' /etc/services
  • sudo launchctl unload -w /System/Library/LaunchDaemons/ssh.plist
  • sudo launchctl load -w /System/Library/LaunchDaemons/ssh.plist

and on client side:

  • sudo sed -i -e 's+#   Port 22+Port 10422+g' /etc/ssh/ssh_config

SSH tunnel for e.g. VNC. Here we assume ssh over port 12345. After this tunnel setup one can use vnc to to reach the other machine:

  • ssh -p 12345 -v -L 5901: destination
  • vnc://



SSH tunnel for SMB for timemachine


Purpose is to tunnel port 445 (SMB) through a ssh tunnel to get past port filtering of some ISP's to allow Apple Timemachine to work to remote servers. This is implemented by creating a network alias to loopback interface in order to have a local tunnel endpoint on port 445 (SMB). Then create keys for ssh if not already there, copy the key(s) to the timemachine server for password-less login. Then create a ssh tunnel from the local alias address to the remote server. The remote disk for backup can then be mounted as a normal smb disk by addressing the local alias address. The procedure:

Create an alias to be able to bind port 445 locally to a tunnel:

  • sudo ifconfig lo0 alias
If not done before: create ssh key to authenticate to remote host, login in the remote host to get the fingerprint added to known hosts, and move public key to remote server:
  • ssh-keygen
  • ssh -p <port>
  • ssh-copy-id -p <port>
Test the ssh for both user and root. Need to test root since we want to forward the privileged port 445 later. This also ensures that the server is in the list of known hosts.
  • ssh -p <port>
  • sudo ssh -p <port> -i /Users/localuser/.ssh/id_rsa
Then set up the tunnel in a way that (hopefully) keeps the tunnel open:
  • sudo ssh -f -C -N -p <port> -i /Users/localuser/.ssh/id_rsa -L -o ServerAliveCountMax=3 -o ServerAliveInterval=15 -o ExitOnForwardFailure=yes
One can also try to use autossh for more tunnel robustness. If not already installed, install autossh and ssh to have the matching version:
  • brew install ssh
  • brew install autossh

Start the tunnel:

  • sudo autossh -M 0 -f -C -N -p <port> -i /Users/localuser/.ssh/id_rsa -L -o ServerAliveCountMax=3 -o ServerAliveInterval=15 -o ExitOnForwardFailure=yes
To create the loopback alias address and the autossh each time the machine is booted, create a script at /usr/local/var and Launch Daemon property list file located at /Library/LaunchDaemons/localhost.startup.plist.

Copy next two pieces of text into your terminal to create the files:

cat > /usr/local/var/ <<EOF
ifconfig lo0 alias
autossh -M 0 -f -C -N -p <port> -i /Users/localuser/.ssh/id_rsa -L -o ServerAliveCountMax=3 -o ServerAliveInterval=15 -o ExitOnForwardFailure=yes

cat >/usr/local/var/localhost.startup.plist<<EOF
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "">
<plist version="1.0">

Then set attributes of the files and copy the plist to the correct place
  • chmod +x /usr/local/var/
  • sudo chmod 644 /usr/local/var/localhost.startup.plist
  • sudo mv /usr/local/var/localhost.startup.plist /Library/LaunchDaemons/localhost.startup.plist
  • sudo chown root:admin /Library/LaunchDaemons/localhost.startup.plist
  • sudo launchctl load -w /Library/LaunchDaemons/localhost.startup.plist
  • sudo launchctl list | grep -i startup
  • ifconfig | grep 127
  • ps aux | grep ssh


Check if alias is up:

  • ifconfig | grep 127
Check if tunnel is present:
  • ps aux | grep tunnel

Unload deamon:

  • sudo launchctl unload -w /Library/LaunchDaemons/localhost.startup.plist


NOTE: this all works but is not persistent. After a reboot the following needs to be redone:

  • sudo ifconfig lo0 alias
  • sudo ssh -f -C -N -p <port> -i /Users/localuser/.ssh/id_rsa -L -o ServerAliveCountMax=3 -o ServerAliveInterval=15 -o ExitOnForwardFailure=yes



Here are TimeMachine cli commands to start up, stop, get info, etc. The info comes from:

The basics of the tmutil command can be found by typing
  • man tmutil
The man page tells you what you can do with this command. For example, to turn Time Machine on or off, you can run these commands:
  • sudo tmutil enable
  • sudo tmutil disable

To get the status of anything going on or progressing:

  • tmutil status
If you want to run a Time Machine backup right away, on a Mac that either has Time Machine disabled, or, say, just before updating to a new version of OS X, you can run this command:
  • tmutil startbackup
This is the same as choosing Back Up Now from the Time Machine menu in the menu bar at the top of your screen. And if you ever want to stop a backup, just run this:
  • tmutil stopbackup
Save disk space on your laptop Since your laptop isn’t always connected to its backup disk, Time Machine retains "local snapshots," or files that it will copy to your backup disk the next time it is available. However, these local snapshots take up space, and you may want to turn this feature off if you don’t have much room on your hard disk. You can turn off (Running this command will also delete any local snapshots.) and on with the following commands:
  • sudo tmutil disablelocal
  • sudo tmutil enablelocal
You can exclude certain files and folders from your Time Machine backups from the Time Machine pane in System Preferences. Naturally, you can also do this from the command line, too. Run this command:
  • sudo tmutil addexclusion <path of folder/file to exclude>
The tmutil addexclusion command has an interesting property: it's sticky. When you use this command, the item you exclude remains in the Time Machine exclusion list even if you move it, which is not the case when you exclude items from the Time Machine preference pane. If you use the above command with the -p flag, then it will not be sticky, and will be the same as an exclusion you add from the Time Machine preference pane.

If you’re managing a remote Mac, such as a server, you may want to change Time Machine settings for that computer. You can start by finding where Time Machine backups are stored. Run this command:
  • tmutil destinationinfo
To change the destination, you can use two commands. First, remove the current destination like this:
  • tmutil removedestination ......
In place of ..... , type in the text string returned by the destinationinfo command. Then run this command to set up a new destination disk:
  • tmutil setdestination volume_name
Replace volume_name with the name of the disk or volume you want to use. You can add multiple destinations as well, since Time Machine can rotate its backups on several disks or volumes. See man tmutil for more on setting up multiple backup destinations. (You can now do this without the command line too, see "How to create redundant Time Machine backups.")

Time Machine saves a lot of backups: one per hour for the past 24 hours; one a day for the past week; and one a week before that. You can get a list of all the backups on your Time Machine disk with this command:
  • tmutil listbackups
The tmutil command offers many other options, such as the ability to inherit destinations, perform detailed comparisons of backups, restore items and much more. See man tmutil to find out all that you can do.


This procedure is to correct errors like: "Time Machine completed a verification of your backups. To improve reliability, Time Machine must create a new backup for you.". It may or may not work. The procedures come from:

The steps:
  • sudo chflags -R nouchg   <the backup bundle>
  • sudo hdiutil attach -nomount -noverify -noautofsck <the backup bundle>

If you have apfs:

  • sudo fsck_apfs -o -v -s   /dev/diskXs2
  • if you get the “Operation not permitted” Error, give the full disk access in the preferences privacy panel.

if you have hfs:

  • sudo fsck_hfs -c 2g -drfy /dev/diskXs2
  • if you get the “Operation not permitted” Error, give the full disk access in the preferences privacy panel.
If you get a message in the fsck_hfs.log along the lines of " RebuildBTree - record x in node y is not r" then try:
  • sudo fsck_hfs -c 2g -p /dev/diskXs2
  • sudo fsck_hfs -c 2g -drfy /dev/diskXs2

To scan for bad blocks:

  • sudo fsck_hfs -S /dev/diskXs2
When succeeded:
  • sudo hdiutil detach /dev/diskXs2
When complete, you need to edit an plist file within the sparsebundle that records the state of the backup. On the top level of the sparsebundle find a file called "".
  • bbedit <the backup bundle>/
Remove these two nodes:


Finally you want to change:


Now Time Machine can give it another go. After the (long) verification step, backups should proceed once again.

To find log file entries:
  • sudo tail -f /var/log/fsck_hfs.log
  • log show --predicate 'subsystem == ""' --info | grep 'upd: (' | cut -c 1-19,140-999

Sometimes a lock on the sparse bundle seems to block mounting the image. Disabling and re-enabling sharing on the server also seems to fail, even after reboot. What worked was stopping and starting the smbd plist:
Quote: Today I've been really logging everything and watching the system constantly and found that if I kill SMB and restart it then everything works again, including unlocking the sharing pane. I use:

  • sudo launchctl unload -w /System/Library/LaunchDaemons/
  • sudo launchctl load -w /System/Library/LaunchDaemons/


How to solve calendar problems



How to solve the error: "Apple Calendar Can’t Save Event to Exchange":


  • Quit Calendar application (Command + Q)
  • Quit Apple Mail
  • Open Activity Monitor (through Spotlight or Launchpad)
  • Search for "Calendar" and quit all the relevant processes
  • Open Finder and navigate to ~/Library/Calendars
  • Double-check Activity Monitor to make sure no Calendar-related processes are running
  • Delete cache files
  • Relaunch Calendar


Network Performance tools



brew install iperf iperf3 nuttcp owamp




  • iperf -s -i 4 -w 3M
  • iperf -i 4 -t 1000 -N -w 3M -l 1M -c [servername]



  • iperf3 -s -i 5
  • iperf3 -i 4 -t 1000 -N -w 3M -l 1M -c [servername]


On the server:

  • nuttcp -S
  • nuttcp [servername]
This runs a 10 second test, only on ipv4


Smart Home - Homebridge



We install node.js using brew:
  • brew install node.js
Check version of node and npm (node package manager):
  • node -v
  • npm -v
Install homebridge:
  • sudo npm install -g --unsafe-perm homebridge homebridge-config-ui-x
Fix remaing errors automattically and install hb-service:
  • npm audit fix
  • npm i --package-lock-only
  • sudo hb-service install
Manage Homebridge by going to one of the following in your browser:

http://localhost:1234 - Default Username: admin - Default Password: admin
Advice is to change the user/pw immediately, and I recommend to set up a https proxy to access homebridge.

To stop/start hombridge:
  • sudo launchctl unload -w /Library/LaunchDaemons/com.homebridge.server.plist
  • sudo launchctl load -w /Library/LaunchDaemons/com.homebridge.server.plist
If you need to remove it:
  • npm uninstall -g homebridge


If the underlying node.js software is upgraded by brew, the homebridge will fail after restart. The correct procedure:

  • sudo hb-service stop
  • sudo launchctl unload -w /Library/LaunchDaemons/com.homebridge.server.plist
  • sudo launchctl load -w /Library/LaunchDaemons/com.homebridge.server.plist
  • sudo hb-service start

Oter usefull commands:

  • Restart Command         sudo hb-service restart
  • Stop Command             sudo hb-service stop
  • Start Command             sudo hb-service start
  • View Logs Command    hb-service logs
File Locations:
Config File Path ~/.homebridge/config.json
Storage Path
Launchctl Service File /Library/LaunchDaemons/com.homebridge.server.plist


Common pitfalls, problems, useful commands


  • After a brew upgrade some services may not work. One difficult to diagnose problem may be the firewall settings in MacOSX. It blocks by default incoming connections on unsigned bin's and executables need to be added in the list in the System Preferences Firewall settings. Also note that just putting there the /usr/local/bin/executable will not work since brew puts aliasses (links) there. Follow the link to the real bin. Same for /usr/local/sbin .
  • After a "brew upgrade" the output may display an error that an old directory could not be removed and a sudo command is displayed. In reality the "brew upgrade" did not complete, so execute that sudo command and repeat "brew upgrade" and displayed error - sudo commands until nothing is being done anymore by that command.
  • Somehow launchd has a different or incomplete PATH environment. Caused certbot renew to initially fail.
  • System upgrade using cli:
    • to get a list of available updates:
      • softwareupdate -l
    • to update a specific package:
      • softwareupdate -i NAME
    • to update all:
      • softwareupdate -i -a
    • for hlep:
      • softwareupdate -h
    • for configuration data
      • softwareupdate -l --include-config-data
    • and
      • softwareupdate -i --include-config-data NAME
  • System version info:
    • Show Apple hardware and software configuration:
      • system_profiler
    • Show Mac OS X operating system version:
      • sw_vers
    • Print just the value of the ProductName property:
      • sw_vers -productName
    • Display the value of the ProductVersion property
      • sw_vers -productVersion
    • Display the build version:
      • sw_vers -buildVersion
  • If the mac is using lots of processes to index for SpotLight, to turn indexing off:
    • sudo mdutil -a -i off
  • and on:
    • sudo mdutil -a -i on
  • If you use screensharing and end the session, the target screen typically goes dark and locks. If you want the screen to stay on, then <see>:
    • sudo defaults write /Library/Preferences/ RestoreMachineState -bool NO
  • A mac that is protected with filevault may not reboot gracefully because a password is needed to access the startup disc. A way to do a reboot is:
    • sudo fdesetup authrestart
  • if you need to log out another user:
    • ps awwwwux | grep loginwindow
    • kill the pid of that user with:
    • sudo kill -9 [pid]
  • Support files can be found HERE.
  • SSH plus Screensharing
    • ssh -p 22 -N -L 5999:localhost:5900
    • vnc://localhost:5999
  • Starting/stopping remote desktop. The commands in this article  work with Apple Remote Desktop 3.2 and later. Here are commands that you can use:
    • Restart the ARD Agent and helper:
      • sudo /System/Library/CoreServices/RemoteManagement/ -restart -agent
    • Turn on Remote Desktop Sharing, allow access for all users, and enable the menu extra:
      • sudo /System/Library/CoreServices/RemoteManagement/ -activate -configure -allowAccessFor -allUsers -privs -all -clientopts -setmenuextra -menuextra yes
    • Turn on Remote Desktop Sharing, allow access for specified users:
      • sudo /System/Library/CoreServices/RemoteManagement/ -activate -configure -allowAccessFor -specifiedUsers
    • You must use the -configure, -access, and -privs options in a separate command to specify the set of users and their access privileges. For example, this command is for users with the short names "teacher" and "student." It gives them access to observe (but not control) the computer, and to send text messages:
      • sudo /System/Library/CoreServices/RemoteManagement/ -configure -users teacher,student -access -on -privs -ControlObserve -ObserveOnly -TextMessages
    • Unlike other kickstart options, you can’t combine the allowAccessFor options with other kickstart options. You must use it as in the last two samples above. You might have to call kickstart more than once to finish a computer’s setup. Remove access privileges for specified users ("student" in this example):
      • sudo /System/Library/CoreServices/RemoteManagement/ -configure -users student -access -off
    • Disable ARD Agent and remove access privileges for all users:
      • sudo /System/Library/CoreServices/RemoteManagement/ -deactivate -configure -access -off
  • Shell need to change from bash to zsh now:
    • The default interactive shell is now zsh. To update your account to use zsh, please run `chsh -s /bin/zsh`. For more details, please visit
      • cp .bash_profile .zshrc
      • chsh -s /bin/zsh
    • restart terminal
      • brew doctor
  • How to get into a home router management interface:
    • TP-Link
    • NetGear
  • Routing
    • lsof -i -P
    • netstat -rn
    • The principles/info/utilities here:



MacMini Setup (for SC/webcam/demo)


This section describes how to set up mac-minies for use as webcam source. Note that EVOCAM is now unsupported and there are probably better ways to achieve webcam streaming. Also the privacy laws allow less and less.

Note that some of the software can also be found here: files directory

  • Users & Groups
    • SNE-Admin
      • sne-admin
    • SNE-demo
      • sne-demo
    • Login Options
      • auto login sne-demo
  • Power settings
    • never sleep computer
    • restart after power fail
    • prevent display sleep
    • awake with net access
    • start up 8h00 in the morning
  • Desktop & Screen Saver
    • no screen saver
  • Sharing
    • Screen Sharing
    • File Sharing
    • Remote login
  • Security
    • turn off screen lock
    • enable location services
    • no filevault
  • Date & Time
    • automatic time adjustment
  • Display
  • MenuMeters
  • BBEdi
  • Deskpicture SNE logo
  • Team Viewer Setup
  • To keep mac from sleeping unexpectedlythat stops video
    • in terminal: caffeinate -di &
  • EvoCam Setup
    • Evocam5 download
      • serial ES56-MUDX-9LD6-BRAG
      • Note:
        • EvoCam 4 crashes now and then but does recording fine, however is 32 bit app!
        • EvoCam 5 is more stable but gives unusable recordings, is 64 bit!
        • NOTE: the low resolution serve must start first, then the high resolution, otherwise video is low quality.
    • Settings
      • Preferences
        • web server port nr 10456
        • Log Web Server access
        • auto-open docs from previous session at startup
        • make sure the low res is loaded first.
        • Finder Cam1.settings on desktop put in dock and set Open at login
        • 320 * 180
        • 384 * 216
        • 480 * 270
        • font size 12
        • framerate 15
        • quality normal normal
        • fontsize 9
      • Cam2.evocamsettings
        • 1280 * 720
        • framerate 15
        • quality normal normal
      • Other resolutions 16*9
      • 256 * 144 -> YouTube 144p
      • 320 * 180
      • 480 * 270
      • 640 * 360 -> nHD
      • 768 * 432
      • 800 * 450
      • 848 * 480
      • 896 * 504
      • 960 * 540 -> qHD
      • 1024 * 576
      • 1152 * 648
      • 1280 * 720 -> HD
      • 1366 * 768 -> WXGA
      • 1600 * 900 -> HD+
      • 1920 * 1080 -> Full HD
      • 2000 * 1125
      • 2048 * 1152
      • 2304 * 1296
      • 2560 * 1440 -> QHD
      • 2880 * 1620
      • 3200 * 1800 -> QHD+
      • 3520 * 1980
      • 3840 * 2160 -> 4K UHD
      • 4096 * 2304 -> Full 4K UHD
      • 4480 * 2520
      • 5120 * 2880 -> 5K UHD
      • 5760 * 3240
      • 6400 * 3600
      • 7040 * 3960
      • 7680 * 4320 -> 8K UHD
      • 15360 * 8640 -> 16K



Online references

In this table are the commands for apache, bind and certbot via brew as in

New info & scratch space

How to set and change different names of the server via CLI.

This information can be useful when configuring your workstation remotely through ssh, or when you need to change the fully qualified hostname of the workstation (which can't be done from the UI).

Note: The following procedure is for informational purposes only and is not an Autodesk certified or supported workflow. Should issues arise with this procedure, they will not be addressed by Autodesk Customer Support.

Perform the following tasks to change the workstation hostname using the scutil command.

Open a terminal.
Type the following command to change the primary hostname of your Mac:
This is your fully qualified hostname, for example
sudo scutil --set HostName <new host name>
so for example:

sudo scutil --set HostName
Type the following command to change the Bonjour hostname of your Mac:
This is the name usable on the local network, for example myMac.local.
sudo scutil --set LocalHostName <new host name>
so for example:

sudo scutil --set LocalHostName flame01.local
Type the following command to change the computer name:
This is the user-friendly computer name you see in Finder, for example myMac.
sudo scutil --set ComputerName <new name>
so for example:

sudo scutil --set ComputerName flame01
Flush the DNS cache by typing:
dscacheutil -flushcache

Restart Mac.
Additional Resources
Type scutil --help for the complete list of parameters.

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