OPERATIONAL DEFECT DATABASE
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IE3300 switch operating as a pure Layer2 switch for the traffic passing through. Traffic sensitive to packet loss [such as high-resolution real-time video] that does not have retransmission capabilities [UDP transport layer] will report packet loss There are no Total Output Drops or Interface Error counters incrementing in older releases [below 17.03.04 and 17.06.01]
IE3300 switch is operating as a pure Layer2 switch for the transit traffic running older IOS-XE release [below 17.03.04 and 17.06.01]
none known at this time in the latest releases [17.03.04 and 17.06.01], the Total output drop counter keeps incrementing, and the count there corresponds to the number of missing packets
This might be difficult to detect/identify in a real-life production network with traffic flows with unknown/unpredictable packet count. It could be confirmed by taking simultaneous packet captures on the ingress and egress interface and confirming that a packet that is seen coming in is not going out and at the same time looking at the I/O graph to make sure that there are no microbursts that could temporarily oversubscribe the egress interface This can be easily seen in the lab, where full control over traffic flows is possible. For example, in a topology where 3 traffic sources are each sending 10M packets to the traffic destination, you will see less than 30M packets transmitted to the traffic destination traffic ----------+ source A | Gi1/3 | +-+--------------+ | IE-3300-8T2S-A | Gi1/4 | | Gi1/6 traffic --------+ +------------+ traffic source B | | destination | | +-+--------------+ Gi1/5 | | traffic ----------+ source C Switch#show controllers ethernet-controller gi1/3 | i Receive|Unicast Transmit GigabitEthernet1/3 Receive 0 Unicast frames 10000000 Unicast frames <============ ingress interface received 10M packets Switch#show controllers ethernet-controller gi1/4 | i Receive|Unicast Transmit GigabitEthernet1/4 Receive 0 Unicast frames 10000000 Unicast frames <============ ingress interface received 10M packets Switch#show controllers ethernet-controller gi1/5 | i Receive|Unicast Transmit GigabitEthernet1/5 Receive 0 Unicast frames 10000000 Unicast frames <============ ingress interface received 10M packets Switch# Switch#show controllers ethernet-controller gi1/6 | i Transmit|Unicast Transmit GigabitEthernet1/6 Receive 29980889 Unicast frames 0 Unicast frames <============ egress interface transmitting less than 30M packets Switch# These drops can be observed via the following command: show platform hardware qos asic 0 port The ASIC_PORT_NUMBER associated with the front panel interface name can be retrieved via the following command: show platform pm port-map The actual issue [QoS drops//egress queueing drops] for traffic below linerate is still under investigation. The "show platform hardware qos asic 0 port " command alone will answer whether there are any QoS drops seen however will not answer whether these are legitimate ones [egress interface is oversubscribed and unable to handle the burst of traffic] or not [egress traffic is below linerate and there are no bursts]
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