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PackEth tutorial part II – The Gen-B,Gen-S and PCAP options

This is a Second part of an article I have written some time ago about the great tool called PackETH.  This article will be much shorted as it will be focused on the less complicated (but not useful!) modes of the tool.

In the previous par I have described how to build your own packet from L2 to L4 but what if you need something else ? maybe not a single packet but a burst of packets? or what is you need to send multiple streams of various frames ? Well then you need to use the Gen-S and Gen-B modes. read more

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PackEth tutorial part I – The Interface and The Packet Builder

In my previous post I have mentioned ingenious piece of software called PackEth and I have also promised that will write up a separate article about it as I just think this amazing tool deserves as much attention as I can give it.  So what this software do?  Well let me quote the author ” PackETH is GUI and CLI packet generator tool for Ethernet…It allows you to create and send any possible packet or sequence of packets on the Ethernet link.” I would add that that it is the only tool I have found that actually allows you to assemble Ethernet frames and a IP packets that actually does what you would expect it to do while being multi-platform and incredibly stable. I think I have never seen it crashing which speaks for itself.  This article will focus around version 1.6 as that is the one that has both Linux and Windows versions available. The drawback is that the L3 IPv6 support is not included. read more

Posted on

PackEth tutorial part I – The Interface and The Packet Builder

In one of my previous posts I have mentioned great piece of software called PackEth and I have also promised that will write up a separate article about it as I just think this amazing tool deserves as much attention as I can give it.  So what does this software do?  Well let me quote the author ” PackETH is GUI and CLI packet generator tool for Ethernet…It allows you to create and send any possible packet or sequence of packets on the Ethernet link.” I would add that that it is the only tool I have found that actually allows you to assemble Ethernet frames and a IP packets that actually does what you would expect it to do while being multi-platform and incredibly stable. I think I have never seen it crashing which speaks for itself.  This article will focus around version 1.6 as that is the one that has both Linux and Windows versions available. The drawback is that at the time of writing the L3 IPv6 support is not included. read more

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DHCP option 82 and DHCP relay

I was actually playing with DHCP relay and what I did find out is kind of interesting. For what is DHCP relay look for rfc3046 .
In short it is when the client sends a DHCP a broadcast message (discover) some device  – usually the switch that is the client directly connected to – intercepts the packet and sends a unicast discover instead of it to remote server over L3. The advantage is that the amount of boadcasts in the networks drops and secondly the DHCP server can be in different subnet. This is great because you can now use centralised dhcp server for all networks. read more