Dropped packets with bonded interface

[Albert Chin]

I'm running 11.10 on an Intel SR2625URLXR system with an Intel S5520UR
motherboard and an Intel E1G42ET Dual Port Server Adapter. I'm getting
dropped packets on a bonded interface:

$ ifconfig -a
...
bond0     Link encap:Ethernet  HWaddr 00:1b:21:b7:21:ea  
          BROADCAST PROMISC MASTER MULTICAST  MTU:1500  Metric:1
          RX packets:2472 errors:0 dropped:2472 overruns:0 frame:0
          TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:306528 (306.5 KB)  TX bytes:272 (272.0 B)

br0       Link encap:Ethernet  HWaddr 00:1b:21:b7:21:ea  
          inet6 addr: fe80::21b:21ff:feb7:21ea/64 Scope:Link
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:7 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:554 (554.0 B)
...
eth2      Link encap:Ethernet  HWaddr 00:1b:21:b7:21:ea  
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
          RX packets:1236 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:153264 (153.2 KB)  TX bytes:116 (116.0 B)
          Memory:b2420000-b2440000 

eth3      Link encap:Ethernet  HWaddr 00:1b:21:b7:21:ea  
          UP BROADCAST RUNNING SLAVE MULTICAST  MTU:1500  Metric:1
          RX packets:1236 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:153264 (153.2 KB)  TX bytes:156 (156.0 B)
          Memory:b2400000-b2420000 

$ cat /etc/network/interfaces
...
auto bond0
iface bond0 inet manual
  bond-slaves none
  bond_mode 802.3ad
  bond_miimon 100

auto eth2
iface eth2 inet manual
  bond-master bond0

auto eth3
iface eth3 inet manual
  bond-master bond0

auto br0
iface br0 inet manual
  bridge_ports bond0
  bridge_stp off

eth2 and eth3 are on the Intel E1G42ET Dual Port Server Adapter.

The switch these two ports are connected to is a Summit 400-48t, with
the ports they're connected to configured for LACP:
  Summit400-48t:1 # show configuration
  ...
  configure sharing address-based ip-source
  ...
  enable sharing 17 grouping 17,21 dynamic
  ...
  Summit400-48t:1 # show ports sharing
  Load Sharing Monitor
  Config    Current    Ld Share    Ld Share   Link     Link
  Master    Master     Type        Group      Status   Ups
  ==========================================================
    17                   dy          17         ND     689  
                         dy          21         ND     115  

  Link Status: (A) Active, (D) Disabled, (LB) Loopback, (ND) Not Distributing
               (NP) Not Present, (R) Ready

  Ld Share Type: (a) address based, (dy) dynamic

1. If eth2 and eth3, which make up bond0, show no dropped packets, why
   am I seeing dropped packets on bond0? I've tested the network
   cables and they're ok. I've tested the two ports on the Intel
   E1G42ET Dual Port Server Adapter and they're ok. I've tested the
   ports on the switch and they're ok. I'm only seeing dropped packets
   when I enable bonding.

2. Why isn't the bond0 interface "up"?

-- 
albert chin (china at thewrittenword.com)