Interface Errors Explained

posted on March 3, 2017 by

“show interface” is one of the more common commands that every network engineer uses. However, sometimes it’s not always clear what some of the displayed interface-level errors mean. This article explains some of the more common errors, their meaning, and possible causes. SymbolErrors * device receives invalid symbols in the frame * points to physical problems Alignment Errors – both conditions must be met: * The number of bits received is an odd byte count * The frame has a Frame Check Sequence (FCS) error * points to MAC layer or physical problems FCS Errors = frames failing FCS check...
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Arista 7150 Series Hardware Based NAT For Unicast Traffic

posted on May 16, 2016 by

Arista 7150 series switches use Intel’s Fulcrum FM6000 (code named ‘Alta’) ASIC for packet processing. The ASIC includes several features for IP header translation including Network Address Translation (NAT). In doing so, packets to be NAT’d are processed by the ASIC which is known as Hardware NAT rather than by CPU known as Software NAT. Hardware NAT provides much better scale and performance compared to Software NAT.  The 7150 series switches can provide 10/40Gbps line rate hardware based NAT  across all Ethernet ports at the same time. The number of available ports varies depending on the particular model – it...
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