SSH login alert by mail Linux or Unix based systems

You can get mail lerts on SSH login to any Linux server using the script below. This script sends mail to predefined email address each time someone successfully logs in by SSH to the machine. I take advantage here of the built-in feature of the OpenSSH daemon – if you create …



Reinstall Checkpoint UTM-1 firewall, the hard way...

Update 2022: This article was written for UTM-1 appliances, the first appliance offered by Checkpoint in 2009. It is no longer available, nor exists anywhere, to the best of my knowledge. The procedure of reinstalling a Checkpoint Appliance (new ones) has changed, and became much easier. So, see this article …



Ping – setting don't fragment bit in Linux/Windows/FreeBSD/Solaris/Cisco/Juniper

Linux Windows FreeBSD Solaris CISCO routers (IOS) Juniper routers (JunOS) Ping. Many times while debugging network problems of various kinds you need to send some packets of desirable size and don’t fragment bit being set. I list below how to do it for the different equipment/OSes. Let’s …



Don't rely on SmartViewTracker only - it may lie

Funny case of WYSIWYG misleading the uninitiated. The case involved a seemingly normally functioning firewall Checkpoint which after a client created rule to allow FTP from any to his server in DMZ (no Nat involved) refused to allow connections though. The client being quite experienced himself entered SmartViewTracker did filter …



Failed to connect to Fortiguard servers

Note: This post was written for FortiOS version 2.8 and 3.x so some commands have changed, for updated debug steps please read Failed to connect to Fortiguard servers verification and debug updated Today I encountered otherwise easy to diagnose misconfiguration only that Fortinet decided to 'hide' this parameter …



You can't set duplex/speed settings of the Fortigate interfaces?

Sometimes you can't set duplex/speed settings of the Fortigate interfaces. Important note: depends on which interface you are trying to set!. Upon careful examination turns out that you can't set duplex/speed settings of 4-port switch interfaces only, i.e. Internal interface of Fortigate 60, 60M, 100A, 200A, and …



Tracking the source of DDOS attack with Cisco IOS ip source tracking

Problem: Enterprise is under Denial Of Service Attack (DDOS) that brings down key elements of the business or the whole network at all. To track the attacker is the first step in handling the attack and unless the flood is coming from inside (most probably not in a well managed …



Checkpoint UTM Appliance or Open Server/Power ?

UTM or Power ? How do you know when logged in with ssh what type of machine you are working with ? I know 3 ways to find it: By the interfaces names , see the difference: UTM (output edited for conciseness) [Expert@Firewall]# ifconfig DMZ Link encap Ethernet HWaddr 00 90 FB …



Change password for console expert user Checkpoint Splat

Update 2022: Checkpoint has disabled changing Expert password with passwd altogether. When trying to run the command, no matter what you enter the result will be an error "bad credentials" and "Authentication token manipulation error". You can only change Expert password in Gaia, either in clish, or the WebUI. As …



Debug VPN in Fortigate - seeing is believing

Updated: 2022 You can't really debug VPN problems with static show commands, if VPN fails to function you HAVE to see it happening real-time. Below I list few debug commands to do just that for IPSEC site-to-site tunnels in Fortigate. Here: 192.168.168.254 - IP address on the LAN …