Network performance and blocking all ICMP packets

[ilin]

Hi,

My ISP is blocking all ICMP packets from anywhere to anywhere. If I ping some of PC-s which are in our network the ping works, but if I try to ping google.com, for example, it says host unreachable. Generally, can this be a reason for downgrading network performance?

Thanks in advance!

[scinerd]

I would say due to current virus's blocking icmp traffic can improve a network. I think it was the welcha worm that used icmp traffic. The network where I work was brought down by a flood of icmp traffic. After we started blocking i tthere was an improvement and people could work during they clean up.

It also depends on how you drop it I think. You can drop it with a reject which tells the machines sending it that it's been rejected then the program can continue. If you just drop the pack the program that sent it will need to time out before moving on.

[cowanrl]

Each filter that is added to a firewall means an extra amount of time is spent examining each packet as it moves in or out of the network. Technically, each filter could degrade the performance of your network.

For security reasons, I have blocked all ICMP traffic on our router at work. After I did that, the number of attempts to hack in to our network decreased tremendously. Any degredation in network performance has been negligable. Download speeds are still the same.
If you attached a network analyzer to the network, the degradation would probably be measurable. It is not perceptable however.

[ilin]

Thank you very much! I've helped me much to understand those ICMP things better! :)
Thanks!!!