I don't know about this specifically, but if it's true I know I had to manually tune the buffers on some 3560's just to make them bearable. I'm in the process of migrating away from them onto a 6500 with WS-X6748-GE-TX's instead. For what it's worth, this was how I tuned the 3560's to drastically reduce (but nowhere near eliminate) the output drops due to the tiny buffers:
mls qos srr-queue output cos-map queue 2 threshold 3 0 1 2 3 4 5 6 7 mls qos srr-queue output dscp-map queue 2 threshold 3 0 1 2 3 4 5 6 7 mls qos srr-queue output dscp-map queue 2 threshold 3 8 9 10 11 12 13 14 15 mls qos srr-queue output dscp-map queue 2 threshold 3 16 17 18 19 20 21 22 23 mls qos srr-queue output dscp-map queue 2 threshold 3 24 25 26 27 28 29 30 31 mls qos srr-queue output dscp-map queue 2 threshold 3 32 33 34 35 36 37 38 39 mls qos srr-queue output dscp-map queue 2 threshold 3 40 41 42 43 44 45 46 47 mls qos srr-queue output dscp-map queue 2 threshold 3 48 49 50 51 52 53 54 55 mls qos srr-queue output dscp-map queue 2 threshold 3 56 57 58 59 60 61 62 63 mls qos queue-set output 1 threshold 2 400 400 100 400 mls qos queue-set output 1 buffers 0 100 0 0 mls qos Props go to some blog I found this on. Hope it helps someone who might be struggling with output drops on this type of platform. -Vinny -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Nikolay Shopik Sent: Thursday, April 05, 2012 3:48 AM To: Tom Sands Cc: Piotr Wojciechowski; [email protected] Subject: Re: [c-nsp] 2960s output drops I hear that 2960S and 3560X have almost similar buffers, do you know something about this? On 04/04/12 23:11, Tom Sands wrote: > Beware that the 2960S incurred a drastic reduction in packet buffers compared > to prior the initial 2960 product line (cut the port buffers in half). > > ________________________________________ > From: [email protected] [[email protected]] > on behalf of Nikolay Shopik [[email protected]] > Sent: Wednesday, April 04, 2012 1:54 PM > To: Piotr Wojciechowski > Cc: [email protected] > Subject: Re: [c-nsp] 2960s output drops > > Hardware is Gigabit Ethernet, address is 2c3f.386c.850c (bia 2c3f.386c.850c) > Description: trestcom > MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec, > reliability 255/255, txload 1/255, rxload 1/255 > Encapsulation ARPA, loopback not set > Keepalive set (10 sec) > Full-duplex, 100Mb/s, media type is 10/100/1000BaseTX > input flow-control is off, output flow-control is unsupported > ARP type: ARPA, ARP Timeout 04:00:00 > Last input 00:00:01, output never, output hang never > Last clearing of "show interface" counters 02:41:55 > Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 2197 > Queueing strategy: fifo > Output queue: 0/40 (size/max) > 5 minute input rate 222000 bits/sec, 139 packets/sec > 5 minute output rate 779000 bits/sec, 159 packets/sec > 1001165 packets input, 123531512 bytes, 0 no buffer > Received 30810 broadcasts (16248 multicasts) > 0 runts, 0 giants, 0 throttles > 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored > 0 watchdog, 16248 multicast, 0 pause input > 0 input packets with dribble condition detected > 1428427 packets output, 830613125 bytes, 0 underruns > 0 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 > > > On 04.04.2012 21:58, Piotr Wojciechowski wrote: >> On 4/4/12 18:35 , Nikolay Shopik wrote: >>> Hi, >>> >>> So we just replaced some aging c3524XL with 2960S and suddenly start >>> seeing output drops on one of port facing client, while 3524 never had >>> output drops to this client. >>> >>> Traffic levels pretty much low like 1-2mbit with 200-300pps levels. I >>> believe this is because uplink now 1Gbit, but previously it was just >>> 100mbit and client port also 100mbit. >>> >>> But just wanna confirm with you guys should I ignore these drops or do >>> something about. >> >> What kind of drops are those? Can you provide us show interface output? >> >> Regards, >> >> > _______________________________________________ > cisco-nsp mailing list [email protected] > https://puck.nether.net/mailman/listinfo/cisco-nsp > archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
