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I ran tiger on my debian 6 system and saw these in my report. Are these much of a problem? How do i fix them? This is my VPS which i use to run websites.

# Checking network configuration
--WARN-- [lin012w] The system accepts ICMP redirection messages 
--FAIL-- [lin013f] The system is not protected against Syn flooding attacks 
--FAIL-- [lin014f] The system permits the transmission of IP packets with 
         invalid addresses 
--FAIL-- [lin016f] The system permits source routing from incoming packets 
--WARN-- [lin017w] The system is not configured to log suspicious (martian) 
--FAIL-- [lin019f] The system does not have any local firewall rules 
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They can be a problem, but a lot depends on where your system is, what it does, and what it is connected to.

In general, running local firewall rules is considered a good thing (especially for websites) and doing that could fix some of the other issues (eg firewall rules to deny source routing, deny ICMP redirect and deny IP spoofing)

If you have firewall rules in place on another device protecting this one, that may be sufficient, but the old "defence in depth" adage is a good one to look at.

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I'm suspecting that you ran Tiger to get some sort of security evaluation. It is a good idea to research any security suggestions that you get (whether from a program or a person) to find out if they are relevant. The people who wrote Tiger think that these findings are issues that need to be addressed. I think that if you googled "linux" plus a few of the key words for each line that you could probably find some background and the configuration changes that you need to make.

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