Postfix restriction classes.

Postfix’ built-in restriction classes are processed in the following order:

smtpd_client_restrictions
smtpd_helo_restrictions
smtpd_sender_restrictions
smtpd_recipient_restrictions
smtpd_data_restrictions

regardless of the order in which they’re listed in main.cf. Restrictions (within a restriction class) are evaluated in the order in which they’re listed.
Processing within a restriction class ends on the first match.

Useful link: http://www.postfix.org/RESTRICTION_CLASS_README.html#external

Obtaining the PPD file from a local and a remote CUPS server

The compressed PPD files on a local CUPS server are located in:

/usr/share/cups/model/

The used PPD files by CUPS server are located in:

/etc/cups/ppd

If your printer is on a remote CUPS server, you can easily download the PPD file to your client with

wget http://server_name_or_IP:631/printers/printer_queue_name>.ppd

Continue reading “Obtaining the PPD file from a local and a remote CUPS server”

Activate RPMFusion repo

The RPMFusion provides some free and non-free software for Fedora.

free – for Open Source Software (as defined by the Fedora Licensing Guidelines) which the Fedora project cannot ship due to other reasons

nonfree – for redistributable software that is not Open Source Software (as defined by the Fedora Licensing Guidelines); this includes software with publicly available source-code that has “no commercial use”-like restrictions

To enable access to just free repository use the following command:
root# dnf install http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm

To enable access to both the free and the nonfree repository use the following command:
root# dnf install http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm

When listing a directory on an NFS share, directory listing fails half way through with ‘ls: reading directory .: Too many levels of symbolic links

Disable the dir_index filesystem feature on the filesystem that is being exported from the NFS server.

root# tune2fs -O ^dir_index /dev/sdXY, where sdXY is your device.

To re-enable the dir_index feature use the command:

root# tune2fs -O dir_index /dev/sdXY, where sdXY is your device.

Change the default Postfix queue ID to a long format.

The benefit of non-repeating names (queue ID) is simpler logfile analysis and easier queue migration. And there is nothing wrong with the default settings 😉

New queue files are created with names such as 3Pt2mN2VXxznjll. These are encoded in a 52-character alphabet that contains digits (0-9), upper-case letters (B-Z) and lower-case letters (b-z). For safety reasons the vowels (AEIOUaeiou) are excluded from the alphabet. The name format is: 6 or more characters for the time in seconds, 4 characters for the time in microseconds, the ‘z’; the remainder is the file inode number encoded in the first 51 characters of the 52-character alphabet.

How this looks now:

Jul 12 17:34:17 bnmrelay postfix/pickup[20475]: DA41A139183: uid=0 from=
Jul 12 17:34:17 bnmrelay postfix/cleanup[21313]: DA41A139183: message-id=<20160712163417.DA41A139183@bnmrelay.domain.com>
Jul 12 17:34:17 bnmrelay postfix/qmgr[30234]: DA41A139183: from=<root@bnmrelay.domain.com>, size=463, nrcpt=1 (queue active)
Jul 12 17:34:18 bnmrelay postfix/smtp[21302]: DA41A139183: to=<testaccount@domain.com>, relay=172.16.53.233[172.16.53.233]:25, delay=0.28, delays=0.05/0/0/0.23, dsn=2.6.0, status=sent (250 2.6.0 <20160712163417.DA41A139183@bnmrelay.domain.com> [InternalId=44586055500327, Hostname=BNM01.domain.com] Queued mail for delivery)
Jul 12 17:34:18 bnmrelay postfix/qmgr[30234]: DA41A139183: removed

And after the change:

Jul 12 17:34:17 bnmrelay postfix/pickup[20475]: 3rpnHt4Sgnz21N4: uid=0 from=
Jul 12 17:34:17 bnmrelay postfix/cleanup[21313]: 3rpnHt4Sgnz21N4: message-id=<20160712163417.DA41A139183@bnmrelay.domian.com>
Jul 12 17:34:17 bnmrelay postfix/qmgr[30234]: 3rpnHt4Sgnz21N4: from=<root@bnmrelay.domain.com>, size=463, nrcpt=1 (queue active)
Jul 12 17:34:18 bnmrelay postfix/smtp[21302]: 3rpnHt4Sgnz21N4: to=<testaccount@domain.com>, relay=172.16.53.233[172.16.53.233]:25, delay=0.28, delays=0.05/0/0/0.23, dsn=2.6.0, status=sent (250 2.6.0 <20160712163417.DA41A139183@bnmrelay.domain.com> [InternalId=44586055500327, Hostname=BNM01.domain.com] Queued mail for delivery)
Jul 12 17:34:18 bnmrelay postfix/qmgr[30234]: 3rpnHt4Sgnz21N4: removed

Install CUPS printer on Windows machine

The IPP is the native protocol of CUPS: Therefore no extra daemon is needed to receive IPP print jobs. The CUPS daemon listens for IPP requests on port 631. Port 631 is the default port for the IPP. Depending on its configuration it also accepts SSL-encrypted IPP, usually on the SSL-port 443. IPP clients can be other machines running Windows, GNU/Linux, Unix, or MacOS X with CUPS.

On the Windows computer, go to Control Panel->Devices and Printers and choose to ‘Add a printer’. Next, choose ‘Select a shared printer by name’ and type in the location of the printer:

ipp://hostname:631/printers/printer_queue_name