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VPN Phase 1 fails – Checkpoint to Cisco – Update

May 22nd, 2009 by devnull | 1 Comment | Filed in Uncategorized
A while back i wrote a post about a problem setting up a vpn tunnel between a cisco router and a checkpoint firewall.

When i tried to open he tunnel, the following error showed up in the log files:
“Duplicate Phase 1 packet detected.  Retransmitting lastpacket.”
Back then i didnt have the time to research the problem, so i still owe you an explanation:
By default, main mode is selected for phase 1 ike on the checkpoint configuration. The router was i trying to connect with, was configured with aggressive mode.
So what was the problem?
The two modes operate differently -
Main mode uses 6 packet in the ike phase 1 and aggressive mode uses only 3.
Aggressive mode identity packets are sent in clear text. This means one can sniff the identity traffic. The main mode first allow the encryption of the identity packets, and only then send them.
While the aggressive mode is faster, as it requires less resources, the main mode is considered more secure.
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How to FAIL at landing a job in Information Security

September 12th, 2008 by devnull | 1 Comment | Filed in Uncategorized

Landing a job as an Information Security Engineer is not easy.

I made up a list that will help you fail at it.

1. Lie on your resume

write down that you:

  • Configured *enter all brand name* Firewalls. Please mention that you know them from the inside out. When actually, you only configured a simple access rule using the GUI.
  • Write down that you built the IPS infrastructure of a large organization. When practically, you watched as a contractor do all the work.
  • Give yourself a title like Sr. Information Security Analyst. Sounds great. Make sure no one will notice that you were the only first level support.

2. Certifications

  • Your only certification is CEH. God i hate this one.
  • Have about 10 different certifications and no hands on experience.
  • Write down that you are CISSP certified, when you only started to study for it. No one will catch up on that.

3. The interview

The fun part right here:

  • Say you were once a hacker (scarry), but you only hacked to make the world a better place. The 80s are over. Get over yourself – FFS, Get a life
  • When asked technical questions, lie lie lie, never say ‘i dont know”.  Remember all the things you wrote in the resume.
  • Assume that the person interviewing you has 0 technical knowledge. He will be very impressed with your stories.
  • Name drop as much as you can. People love to hear buzz words.
  • Say that you are right for the job. True were a pc technician, but you took a course and passed the CEH exam. You really like this stuff.

The hands on lab

This is your chance to stand out (and if you are up, can you please head to the door?).

  • We set up a computer with internet access. Dont use it. Hey you are so knowledgeable.. Fail #1
  • You just ran into a small problem. Dont try to overcome it. Everyone likes a quitter. Fail #2
  • Things are not going well for you. Blame it on the equipment. Say its broken. Sure it is. Fail #3
  • You run into a device for the first time. Dont read the quick getting started guide. Go directly to the CLI. That would impress us. Gee just like the matrix. Fail #4
  • On the other hand, when handling a firewall (the one you mentioned on your CV), look surprised when you realize there is more than the GUI. Fail #5

This is the part when i say we will be in touch.


VPN Phase 1 fails – Checkpoint to Cisco

May 12th, 2008 by devnull | 1 Comment | Filed in Uncategorized, firewalls

I recently encountered a problem setting up a VPN tunnel between a Cisco router and a Checkpoint firewall.

From the firewall side, i could see an IKE packet going out, and nothing coming back.

On the Router side, there was a reply to the IKE, but an error logged:

“Duplicate Phase 1 packet detected.  Retransmitting lastpacket.”

Now this error should appear if the reply is discarded on the firewall side, and it tries to re-send the initial IKE packet.

Nothing indicated it in the firewall log.

What solved it was enabling Aggressive Mode on the firewall side.

I didnt have the time to go over and see why this helped, but it did the trick, so i moved on.

Another thing, and this is more of a reminder for me, the command for tunnel handling on checkpoint, is “vpn tu”. There you can see all the tunnels, and delete them.

If you know what caused this, please share :D

Update – here is why

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