This is a quick post about a security mechanism that was being a pain-in-the-arse so like any good SA I just disabled it.
I was consistently receiving this message in /var/log/messages when trying to fix a configuration issue with snort:
rsyslogd-2177: imuxsock begins to drop messages from pid 12490 due to rate-limiting
To allow any process unlimited logging to syslog add the following line to /etc/rsyslog.conf:
$SystemLogRateLimitInterval 0
Then to restart the service (on Centos/RHEL/Fedora) run:
service rsyslog restart
2.25.2013
2.19.2013
Write Failed: Broken Pipe
I was having this issue today about every 2-5 minutes when connecting to my local ssh server from a Ubuntu 12.04 desktop. After some quick googling I found this little nugget that I thought I'd share.
Add this line to your /etc/ssh/ssh_config file on your client machine in my case the Ubuntu desktop:
Add this line to your /etc/ssh/ssh_config file on your client machine in my case the Ubuntu desktop:
ServerAliveInterval 120Send root's mail to someone else using aliases
PURPOSE:
This is helpful if you want the root account's mail to go to another system or email address.
ENVIRONMENT:
PROCEDURES:
First things first make sure that postfix is configured correctly for root to send recieve mail.
See this post about configuring postfix to relay mail through gmail:
http://systemstuds.blogspot.com/2013/02/postfix-configured-to-send-mail-through.html
Now that you have postfix set up correctly run: vi /etc/aliases
Press: shift+g (this vi trick will take you to the last line of the file)
Press: o (this will take you into edit mode below the cursor)
Now add a line to look like this:
root: someemailaddress@gmail.com
Press: :wq (to save an quit the file)
Next, run: newaliases
Newaliases rebuilds the random access data base for the mail aliases file /etc/aliases. It must be run each time this file is changed in order for the change to take effect. (man page)
Finally, test your new configuration: mail root
You should now see your test mail in your email account.
As always check /var/log/maillog for problems if you didn't recieve the email.
Good Luck!
This is helpful if you want the root account's mail to go to another system or email address.
ENVIRONMENT:
- Centos 6
- 2.6.32-279.22.1.el6.i686
- postfix-2.6.6-2.2.el6_1.i686
PROCEDURES:
First things first make sure that postfix is configured correctly for root to send recieve mail.
See this post about configuring postfix to relay mail through gmail:
http://systemstuds.blogspot.com/2013/02/postfix-configured-to-send-mail-through.html
Now that you have postfix set up correctly run: vi /etc/aliases
Press: shift+g (this vi trick will take you to the last line of the file)
Press: o (this will take you into edit mode below the cursor)
Now add a line to look like this:
root: someemailaddress@gmail.com
Press: :wq (to save an quit the file)
Next, run: newaliases
Newaliases rebuilds the random access data base for the mail aliases file /etc/aliases. It must be run each time this file is changed in order for the change to take effect. (man page)
Finally, test your new configuration: mail root
You should now see your test mail in your email account.
As always check /var/log/maillog for problems if you didn't recieve the email.
Good Luck!
Postfix configured to send mail through gmail as relay host
This is going to be my first blog post so cut me some slack. These posts will become more professional as the blog matures.
PURPOSE:
Why do this? I wanted my home Linux server to send me logwatch logs, alerts and shit to my personal gmail account. I wanted to use postfix since it’s the resident smtp server and didn’t feel the need to install any additional garbage.
ENVIRONMENT:
First, make sure the following lines exist in your /etc/postfix/main.cf (the most important lines are bold):
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
mail_owner = postfix
inet_interfaces = localhost
inet_protocols = all
myhostname = kong.example.com
mydestination = kong.example.com
unknown_local_recipient_reject_code = 550
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.6.6/samples
readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
##########
# Forward mail through Gmail
relayhost = [smtp.gmail.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_CAfile = /etc/pki/tls/cert.pem
Next, create the /etc/postfix/sasl_passwd file with the following one liner:
[smtp.gmail.com]:587 crazyemailaddress@gmail.com:cr@zypas$word
Next, run this command: sudo postmap /etc/postfix/sasl_passwd
IMPORTANT SECURITY TIP: Make sure you give full ownership to root with 600 permissions because your email credentials will be stored in cleartext.
Restart your mail server: service postfix restart
Extra step for root mail forwarding using aliases:
http://systemstuds.blogspot.com/2013/02/send-roots-mail-to-someone-else-using.html
Finally, test your configuration:
mail someemailaddress@gmail.com
If you didn’t receive the email check your /var/log/maillog for problems. I had a certificate issue my first go round. Then I had to check that gmail didn’t lock my account out for sending too much spam
Good Luck!
PURPOSE:
Why do this? I wanted my home Linux server to send me logwatch logs, alerts and shit to my personal gmail account. I wanted to use postfix since it’s the resident smtp server and didn’t feel the need to install any additional garbage.
ENVIRONMENT:
- Centos 6
- 2.6.32-279.22.1.el6.i686
- postfix-2.6.6-2.2.el6_1.i686
First, make sure the following lines exist in your /etc/postfix/main.cf (the most important lines are bold):
queue_directory = /var/spool/postfix
command_directory = /usr/sbin
daemon_directory = /usr/libexec/postfix
data_directory = /var/lib/postfix
mail_owner = postfix
inet_interfaces = localhost
inet_protocols = all
myhostname = kong.example.com
mydestination = kong.example.com
unknown_local_recipient_reject_code = 550
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
debug_peer_level = 2
debugger_command =
PATH=/bin:/usr/bin:/usr/local/bin:/usr/X11R6/bin
ddd $daemon_directory/$process_name $process_id & sleep 5
sendmail_path = /usr/sbin/sendmail.postfix
newaliases_path = /usr/bin/newaliases.postfix
mailq_path = /usr/bin/mailq.postfix
setgid_group = postdrop
html_directory = no
manpage_directory = /usr/share/man
sample_directory = /usr/share/doc/postfix-2.6.6/samples
readme_directory = /usr/share/doc/postfix-2.6.6/README_FILES
##########
# Forward mail through Gmail
relayhost = [smtp.gmail.com]:587
smtp_use_tls = yes
smtp_sasl_auth_enable = yes
smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd
smtp_sasl_security_options = noanonymous
smtp_tls_CAfile = /etc/pki/tls/cert.pem
Next, create the /etc/postfix/sasl_passwd file with the following one liner:
[smtp.gmail.com]:587 crazyemailaddress@gmail.com:cr@zypas$word
Next, run this command: sudo postmap /etc/postfix/sasl_passwd
IMPORTANT SECURITY TIP: Make sure you give full ownership to root with 600 permissions because your email credentials will be stored in cleartext.
Restart your mail server: service postfix restart
Extra step for root mail forwarding using aliases:
http://systemstuds.blogspot.com/2013/02/send-roots-mail-to-someone-else-using.html
Finally, test your configuration:
mail someemailaddress@gmail.com
If you didn’t receive the email check your /var/log/maillog for problems. I had a certificate issue my first go round. Then I had to check that gmail didn’t lock my account out for sending too much spam
Good Luck!
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