EtherSam (Y.1564) explained

This is the last article (at least for now) from the series about testing methodologies and testing standards. I will cover some bits and pieces in the region of testing in general but it won’t be as heavy on the theory as I want to write some “hands-on” scenarios for combined use of Wireshark and PackEth as well as about some multicast scenarios. Also I will be doing more Cisco and Juniper stuff so it is quite likely I will be blogging some configs and labs. Anyway enough about the future plans and let’s start with the topic at hand. read more

Port isolate vs. Mac Forced Forwarding

Let me first say that these two features are supposed to do very similar things – they are designed to separate access users so their traffic cannot go directly between them without any control. The firs possible solution is a port-isolate command which separates L2 and L3 traffic between the isolated (access) ports. This leads to complete separation with all the advantages and disadvantages. The biggest disadvantage is that all traffic trunked up to another switch where it will be dealt with – usually it will be routed. As the separation is also on L2 and L3 you cannot use arp proxy which could resolve the overhead on access switch. The advantage is that the separation is absolute which could be quite useful in ISP’s access networks. read more

IPsec overview

IPSec is a framework of symmetric encryption of IPv4 protocol which is good for VPN creation etc. Parts of the IPSec are Internet Key Exchange (binding all the pieces together), Diffie-Hellmanalgorithm (for secure key exchange) and symmetric pre-shared key or certificate based authentication. This main three components make IPSec very reliable and very difficult to break into (even though some of the algorithms are weak/vulnerable). read more

RFC2544 Testing explained

This next article in this mini-series about testing Ethernet/IP networks I will write about one of the most common test – the RFC2544  ”Bench-marking Methodology for Network Interconnect Devices”. The purpose of this test is quite often misunderstood even though it is clearly stated in the introduction of the standard itself. So let’s start with clarifying what this testing suite is and what it should be used for. read more