Hi, We have a 6 switch stack that is split between two cabinets, switches 1-3 in the left cabinet, 4-6 in the right. We need to add a new switch to each cabinet. I am confident adding a switch to the bottom of a stack and know the do's and dont's but adding a switch in the middle I am unsure. Would this work? Add to the stack config "switch 7 provision ws-c3850-48p, switch  8  provision ws-c3850-48p " Renumber switches 4-6 to 5-7 Provision two new switches as switch 4 and switch 8 The above shouldn't cause any downtime and can be done in preparation. Then Power down switches 5-7 and remove stacking cables Then add switch 4, then 5, then 6, then 7 and then 8. Is this the correct way of doing it? If it is do I have to wait for each new switch to load fully before adding the next one? The current stack looks like this * 1 56 WS-C3850-48P 03.06.05E cat3k_caa-universalk9 INSTALL 2 56 WS-C3850-48P 03.06.05E cat3k_caa-universalk9 INSTALL 3 56 WS-C3850-48P 03.06.05E cat3k_caa-universalk9 INSTALL 4 56 WS-C3850-48P 03.06.05E cat3k_caa-universalk9 INSTALL 5 56 WS-C3850-48P 03.06.05E cat3k_caa-universalk9 INSTALL 6 56 WS-C3850-48P 03.06.05E cat3k_caa-universalk9 INSTALL We will be updating the software to 03.07.05E   Many thanks, Paddy ... View more

Hi, We have a Nexus 7000 Software BIOS: version 3.1.0 kickstart: version 6.2(16) system: version 6.2(16) BIOS compile time: 02/27/2013 kickstart image file is: bootflash:///n7700_s2_kickstart.6.2.16.bin kickstart compile time: 1/27/2016 9:00:00 [04/05/2016 21:11:19] system image file is: bootflash:///n7700_s2_dk9.6.2.16.bin system compile time: 1/27/2016 9:00:00 [04/05/2016 22:15:44] Hardware cisco Nexus7700 C7706 (6 Slot) Chassis ("Supervisor Module-2") Intel(R) Xeon(R) CPU with 32745060 kB of memory. Processor Board ID JAE184403VZ   We recently connected a switch to port e1/48. The uplink is set as a trunk at both ends, all devices on the switch are in vlan 10, however the config on the nexus was as follows: interface Ethernet1/48 description link-id-10 switchport switchport mode trunk no shutdown so no specific switchport trunk allowed vlan.... command. The link came up and we were able to ping devices on the switch. Then 5 minutes later we noticed the pings dropping 100%. #show cdp neighbor showed the switch at the other end but #show int trunk showed that there were no vlans allowed for int e1/48. I then did a #show run int e1/48: interface Ethernet1/48 description  link-id-10 switchport switchport mode trunk switchport trunk allowed vlan none no shutdown I then specifically added vlan 10 to the interface trunk, shut, no shut, but the layer 2 link wouldnt come back up and we had to back out of the change (this is a live environment). There were no logs for this either. I know it is best practice to specifically state what vlans are allowed, normally we do, but what would cause the link to come up and work only for it to then stop working a few minutes later?    Many thanks, P ... View more

Hi, We have a c3850 in our data centre with a fibre 1 Gbps layer-2 link to a remote site. We are seeing output drops on this interface at random times in the day, in the past 24hrs there have been nearly 2,000,000 drops and users are reporting slow network. Their actual utilization is very low, around 5Mbps with occasional spikes at 20Mbps, so not even touching the sides.  Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 2412072 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 680000 bits/sec, 330 packets/sec 5 minute output rate 2598000 bits/sec, 438 packets/sec 34581067 packets input, 10213669927 bytes, 0 no buffer Received 569985 broadcasts (272695 multicasts) 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 272695 multicast, 0 pause input 0 input packets with dribble condition detected 48843768 packets output, 38999739203 bytes, 0 underruns 2412072 output errors, 0 collisions, 0 interface resets 0 unknown protocol drops 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier, 0 pause output 0 output buffer failures, 0 output buffers swapped out Should I see about increasing the output buffer from the default of 40? If so should I double it or make it much larger eg 1000? And will I be able to do it without bringing the link down? Are there any debug commands I could run on that interface to capture when these drops are happening?   Many thanks for any help, P ... View more