You donвЂ™t know if the packet was dropped because the switch was misconfigured, because the server was misconfigured, or something else completely. When you check that counter, the switch says, вЂњOh, youвЂ™ve now dropped 504 packets, due to a bad VLAN.вЂќ Those switches donвЂ™t tell you anything about the packet that was dropped, when it was dropped, or why it was droppedвЂ“just that it was dropped. The most those switches do is increment a vague counter. The packet, and all that useful diagnostic information, just disappears. When a non-NVIDIA switch drops a packet, that packet is sent to bit heaven, never to be seen again. Many other switch telemetry solutions donвЂ™t deliver enough data to diagnose and solve problems. Sometimes itвЂ™s for bad reasons and sometimes itвЂ™s for good reasons. Pretty much every network in the world is going to have some packet drops. In lossless environments, like NVMe over Fabrics (NVMe-oF) running on RoCE, you might have performance problems even though you are not dropping packets.В The performance issues could be due to congestion issues, excessive pause frames, or latency issues.В ItвЂ™s common to find out that the root cause is uneven load balancing across a LAG or ECMP group.В Whether your problem is packet drops or poor performance without packet drops, WJH was built to get to the bottom of those things and give you the best streaming telemetry for superior network visibility. For example, if youвЂ™re hitting a bunch of ACLs, and theyвЂ™re dropping packets, youвЂ™d like to know why, because you might have a corrupted server or VM.В Or, you might have a poorly configured ACL thatвЂ™s causing problems. WJH alerts you to congestion, buffer problems, or even security issues. WJH monitors from the switch ASIC at line rate to alerts on packet drops, congestion events, routing loops, and moreДЇor example, if youвЂ™re dropping packets because of a bad cable or bad optic, WJH shows you those dropped packets and tell you why they were dropped. WJH is a switch-level monitoring solution where the switch ASIC monitors flows at line rate and alerts you if you had performance problems due to packet drops, congestion events, routing loops, and so on.ДЇigure 3. Without that understanding, itвЂ™s impossible to run the network efficiently or to grow it properly. Most network teams donвЂ™t really know if their networks are under-used or over-used because they have poor visibility into whatвЂ™s really going on. Others are trying to get more out of their network. Some network admins want better streaming telemetry to improve their вЂњmean time to innocence.вЂќ They want to speed up the time to find the root cause of issues so they can rule out whatever is NOT causing the problem and prove if itвЂ™s really the server teamвЂ™s fault (or maybe the storage teamsвЂ™ fault). As the networks gets larger and faster, savvy administrators are using fewer protocols but aiming for more network telemetry to achieve better visibility. The main exception to the simplification trend is the need for more visibility, as smart folks want to see whatвЂ™s going on inside their network. Network have been simplified through the support of fewer protocols while telemetry as been growing. IвЂ™ve seen this trend to move to more е…ѓ and away from L2 and all the versions of spanning tree, and band-aids like root guard, loop guard, BPDU guard, and the rest.ДЇigure 2. You could estimate the number of problems by the length of the config files. The larger, or more advanced the data center, the fewer the protocols they like to run.Д«ack in my tech support days, we used to have a saying that, вЂњThe smarter the customer, the shorter the config file.вЂќ The customers who always had trouble seemed to be those who enabled every possible feature and protocol. But over the last several years thereвЂ™s been a trend in data center networks towards simplification. The legacy position on network management has been that more is better: more protocols, more packets captured, and-in case of a problem-more deep digging through captured packets to find the cause and then the fix. Shift from protocols to streaming telemetry Switch streaming telemetryВ can give you that crucial visibility. And the faster your network runs, or the more critical network performance is to your business, the more important that becomes. You need visibility into whatвЂ™s going on inside the network fabric. The same is true if you are running a data center, deploying VMs and containers, or managing a storage deployment. Whether you are driving a car or flying a plane, you need good telemetry, and the faster you travel, the more critical it is. ThatвЂ™s all the data you need to get you safely to where you want to go and to know how the car is doing along the way. When youвЂ™re driving a car, telemetry is the speedometer, tachometer, gas gauge, oil pressure gauge, engine temperature, and dashboard warning lights. What Just Happened provides critical visibility into your switches performance

L2 server status