Hi folks, Does anybody know what causes the router to drop packets as overrun and what as an input queue drops. There are two show interface examples of NPE-G1, both with input hold-queue set to 4096. The first one only shows 153 overrun packets, in the second interface output you can see overruns together with input queue drops:
GigabitEthernet0/1 is up, line protocol is up ... Input queue: 0/4096/0/58537 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/4096 (size/max) 1 minute input rate 43040000 bits/sec, 6944 packets/sec 1 minute output rate 23483000 bits/sec, 7180 packets/sec 2609205324 packets input, 3131277093 bytes, 6 no buffer Received 2871721 broadcasts (0 IP multicasts) 0 runts, 0 giants, 2 throttles 153 input errors, 0 CRC, 0 frame, 153 overrun, 0 ignored 0 watchdog, 2871721 multicast, 0 pause input GigabitEthernet0/3 is up, line protocol is up ... Input queue: 0/4096/4258004/961350 (size/max/drops/flushes); Total output drops: 44638280 Queueing strategy: Class-based queueing Output queue: 6/4096/0 (size/max total/drops) 1 minute input rate 15685000 bits/sec, 5120 packets/sec 1 minute output rate 28836000 bits/sec, 5171 packets/sec 2503236491 packets input, 208082741 bytes, 589462 no buffer Received 1329388071 broadcasts (13 IP multicasts) 0 runts, 12 giants, 960 throttles 128042 input errors, 12 CRC, 0 frame, 128018 overrun, 0 ignored 0 watchdog, 1424143105 multicast, 0 pause input Thanks Ivan On Thursday 05 November 2009 21:38:53 Gert Doering wrote: > Hi, > > On Thu, Nov 05, 2009 at 01:41:16PM -0500, Drew Weaver wrote: > > Does anyone have any tips on finding out what is causing it to > > overrun? > > "Hardware too slow error" - packets arrive in short bursts at line rate, > and your router cannot handle that. > > For example, an NPE-G1 will handle packets at, say, 300 mbit/sec if they > come in evenly spaced - packet<pause>packet<pause>packet<pause> - but if > 1000 packets arrive back-to-back and then a longer pause, it will > overrun the buffers. > > There's not much you can do, except "get a hardware forwarding box" > or "just accept it, and only worry if the errors increase more > frequently". > > We do some of both :-) > > gert > _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/