By default postfix limits the attachment size to about 10 MB. You can determine the current limit with the following command: # sudo postconf | grep message_size_limit message_size_limit = 10240000 To increase the limit add (or change) the following setting in the file /etc/postfix/main.cf: # 20MB message_size_limit = 20480000 After restarting the postfix service the [...]
Read more…Posts Tagged ‘Debian’
Debian Lenny 5.0: Bind RPC port mapper portmap to local loopback
By default on Debian Lenny the portmap service listens on UDP port 111. For security reasons it could by reasonable to prevent portmap from opening the port if you do not run services like NFS or NIS services that depend on a RPC port mapper like portmap. One way to to disable the open port [...]
Read more…XenServer 5.6 & Debian Lenny: Fix apt-get/aptitude GPG error
If you follow the instructions in the Citrix Developer Network to set up a (paravirtualized) Debian Lenny guest system apt-get or aptitude will show the following error W: GPG error: http://updates.vmd.citrix.com lenny Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 841D6D8DFE3F8BB2 W: You may want to run apt-get [...]
Read more…Debian/Ubuntu: Basic Apache 2 security
Update 2010-10-25: I’ve added “TraceEnable Off” to the configuration (which is not the default on Debian). If you run an Apache 2 web server on a production system, it is always a good idea to make some easy configuration changes in /etc/apache2/conf.d/security to increase the server’s security: # Disable access, directory indexing and .htaccess files [...]
Read more…Debian/Ubuntu & Apache 2: Transparent reverse proxy with mod_proxy
Here is a tutorial how to use the apache module mod_proxy to set up a transparent reverse proxy that passes all requests to another web server. Under Debian or Ubuntu you have to enable the modules proxy and proxy_http: # sudo a2enmod proxy # sudo a2enmod proxy_http A use case for a transparent proxy is [...]
Read more…Debian/Ubuntu: Multi network/gateway ip routing setup
If you would like to connect your Debian or Ubuntu system to more than one network (e.g. with more than one physical or virtual network device) you could use the following ip routing setup to use a specific gateway for each network. Create a configuration file in /etc/network/if-up.d/ (like /etc/network/if-up.d/routing) and add one section for [...]
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