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On 01/29/2013 09:45 AM, James wrote: |
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> Hello, |
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> |
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> From here: http://ebtables.sourceforge.net/ |
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> |
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> |
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> We read: |
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> The ebtables tool can be combined with the other Linux filtering tools |
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> (iptables, ip6tables and arptables) to make a bridging firewall that is also |
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> capable of filtering these higher network layers. This is enabled through the |
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> bridge-netfilter architecture which is a part of the standard Linux kernel. |
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> |
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> |
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> Can someone explain to me when/how you would use ebtables |
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> for enhanced security, or forward me to a good written |
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> presentation on when, why or how to deploy ebtables? |
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> Maybe a package already blends these components together? |
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> I recently saw ebtables pop up in a commercial product |
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> ( sniffed terminal boot session) offered by Seimens...... |
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> |
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tl;dr ebtables makes it easy to isolate your interfaces in an unsafe |
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environment. |
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This was over a year ago, and the project fell through, so this is just |
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from memory: |
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We were planning on hosting a very insecure electronic health thingy |
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that "needs to run on a server" (if you want support). The doctors who |
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use it don't have the expertise to maintain it, and the people who sell |
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it didn't have the expertise to do much of anything in my opinion. |
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Since it was "just" a java web application, the servers didn't need to |
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be powerful. But for HIPAA (and my own peace of mind) we wanted the |
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servers to be as isolated as possible. We decided on using KVM virtual |
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machines, each bridged through to its own public IP address on the host. |
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For preventing *external* traffic, iptables is fine. We obviously don't |
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want the RDP ports open to the world, for example. But how do we prevent |
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one VM instance from communicating with another? One doctor's office |
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shouldn't be able to connect to another office's server. If Dr. Foo |
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notices that he can crash his application by entering nonsense into the |
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login form, then he might suppose that he could crash Dr. Bar's |
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application by doing the same thing. |
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So anyway, my memory of this is all very wishy-washy, but ebtables |
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turned out to be the best way to implement those inter-VM restrictions. |
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It could probably have been done in iptables, but ebtables made it easy |
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to say "don't let these two talk." |
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