Subject: Re: Measuring dropped packets
To: None <tech-net@netbsd.org>
From: Christoph Kaegi <kgc@zhwin.ch>
List: tech-net
Date: 10/26/2006 16:19:16
On 26.10-15:14, Manuel Bouyer wrote:
> You can also look at netstat -q, to see if there are drops at a highter
> level. If you see drops here you can try to bump IFQ_MAXLEN
> to something larger than 256.
---------------------------- 8< ----------------------------
# netstat -q
arpintrq:
queue length: 0
maximum queue length: 50
packets dropped: 826
ipintrq:
queue length: 0
maximum queue length: 256
packets dropped: 91897332
---------------------------- 8< ----------------------------
Ugh! Seems like a lot of dropped packets on the last line.
Can you explain, where exactly that these packets were
dropped?
>
> Also look at vmstat -m, especially for failed requests to mbpl and mclpl.
> If there are failed requests you have to bump NMBCLUSTERS (you'll have to
> if you bump IFQ_MAXLEN anyway, I think)
---------------------------- 8< ----------------------------
intfw (primary)# vmstat -m
vmstat: Kmem statistics are not being gathered by the kernel.
Memory resource pool statistics
Name Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
mbpl 256 3436 0 0 216 0 216 216 1 inf 1
mclpl 2048 1501 0 0 755 0 755 755 4 1024 4
---------------------------- 8< ----------------------------
>
> You may also want to install something like pkgsrc/net/mrtg, to
> monitor traffic, in both byte count and packets counts (the script provided
> in the above package does byte count, but it's trivial to change it to
> do packets count too)
>
I'm running nload at the moment which says for the outer interface:
---------------------------- 8< ----------------------------
Incoming: Outgoing:
Curr: 11.92 MBit/s Curr: 3.34 MBit/s
Avg: 11.67 MBit/s Avg: 6.67 MBit/s
Min: 0.00 MBit/s Min: 0.90 MBit/s
Max: 61.23 MBit/s Max: 44.10 MBit/s
---------------------------- 8< ----------------------------
I'm going to look at where to bump IFQ_MAXLEN now...
Thanks and until later
Chris
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Christoph Kaegi kgc@zhwin.ch
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