All posts by PF

iptables unban ip and ban entire subnet

Linux,

iptables

unban ip

List entries with line numbers

iptables -L -v --line-numbers

Delete entry

iptables -D name_of_chain number_of_line_with_IP_that_you_want_to_delete

Let’s imagine that we want to unban 91.194.16.60! chain name is ‘f2b-sshd‘ and line number is 10!

f2b-ssh-unban

iptables -D f2b-sshd 10
Ban entire subnet

Example (banning some chinese sh*t)

iptables -A INPUT -s 119.249.54.0/24 -j DROP
iptables -A INPUT -s 121.18.238.0/24 -j DROP

 

Ubuntu Nagios NRPE – 1, 2, 3 install!

nagios, Ubuntu,

 

0. Update the system

apt-get update && apt-get upgrade

1. Install nagios nrpe & nagios plugins

apt-get install nagios-nrpe-server nagios-plugins

2. Configure NRPE

vi /etc/nagios/nrpe.cfg

Search for server_address and replace 120.0.0.1 for the public ip of this machine.
Search for allowed_hosts and replace 120.0.0.1 for the IP of your nagios server.

3. Restart NRPE

/etc/init.d/nagios-nrpe-server restart

That’s kinda it…

Dell PowerEdge R220, 2 × 2 TB SATA

Sh*ts,

largepng
Got a new DELL R220 to replace two existing servers… the HP DL120G7 and the SuperMicro Intel® C2750 (Avoton).

Manufacturer: Dell PowerEdge R220
Processor: Xeon E3 1x Intel® Xeon® E3 1230 v3 4 C / 8T @3.3 Ghz cache L3 8MB, x64, VT
Memory: 32 GB DDR3 ECC
Storage: 2 × 2 TB SATA

This time, I’m using CentOS!

“This certificate was signed by an untrusted issuer” problem after updating to Mac OS.

Sh*ts, ,

“This certificate was signed by an untrusted issuer” problem after updating to Mac OS.

Your computer has expired certificates.
To solve this make the following actions:

  1. Applications > Utilities > Keychain Access.
  2. Select
    a) Keychain: Login and
    b) Category: Certificates
  3. Scroll each certificate and if it has expired delete it.

Related links