Subject: Difference between device statistics from ifconfig and ip -s l l

From: Milan Kocian <[email-masked]>
Date: Wed, 17 Oct 2007 11:27:00 +0200

hello,

see dropped packets, please:

sit:~# ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:04:23:D6:D5:DE  
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:522284892 errors:0 dropped:16800 overruns:0 frame:0
          TX packets:506064445 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1405350664 (1.3 GiB)  TX bytes:4082649020 (3.8 GiB)
          Base address:0xac00 Memory:ff6e0000-ff700000 

see via ip l l (here are no dropped packets):

sit:~# ip -s l l dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc htb qlen 1000
    link/ether 00:04:23:d6:d5:de brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast   
    2494988681 523755694 0       0       0       57458  
    TX: bytes  packets  errors  dropped carrier collsns 
    453184821  507470461 0       0       0       0      

but see more detailed stats (dropped packet are as missed in RX errors ?!):

sit:~# ip -s -s l l dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc htb qlen 1000
    link/ether 00:04:23:d6:d5:de brd ff:ff:ff:ff:ff:ff
    RX: bytes  packets  errors  dropped overrun mcast   
    2752159866 524110163 0       0       0       57485  
    RX errors: length  crc     frame   fifo    missed
               0        0       0       0       16800  
    TX: bytes  packets  errors  dropped carrier collsns 
    607359337  507807361 0       0       0       0      
    TX errors: aborted fifo    window  heartbeat
               0        0       0       0      

Is this bug or feature ? From my point of view is somewhere lost any sum.
Or is it driver dependent? Kernel 2.6.23.1 (in 2.6.20.20 is the same behavior), 
driver e1000. iproute2-ss070313; net-tools 1.60, ifconfig 1.42 (2001-04-13)
 
Regards,

-- 
Milan Kocian