Dropped packets with bonded interface

[James Gray]

Hi Albert,

See below… 

On 12/11/2011, at 3:58 AM, Albert Chin wrote:

> 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)

--- >8 --- Snipped

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

The dropped packets on bond0 are probably control packets the kernel is ignoring because you haven't enslaved any interfaces.  Which leads to question 2.  Try modifying the "iface bond0" stanza in /etc/network/interfaces:

auto bond0
iface bond0 inet manual
  bond-slaves eth2 eth3   # No slaves == nothing for bond0 to bind to!
  bond_mode 802.3ad
  bond_miimon 100

You might want to add an "updelay" in there too if your interfaces take a little while to synchronise with the switch (easy for the switch to block the port until spanning tree has done its thing unless you've specify "portfast" on the switch port).  Then bounce the network and see what happens.  When it's all running properly, you should see something like this:

# cat /proc/net/bonding/bond0                      
Ethernet Channel Bonding Driver: v3.6.0 (September 26, 2009)

Bonding Mode: IEEE 802.3ad Dynamic link aggregation
Transmit Hash Policy: layer2 (0)
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

802.3ad info
LACP rate: slow
Aggregator selection policy (ad_select): stable
Active Aggregator Info:
	Aggregator ID: 1
	Number of ports: 2
	Actor Key: 17
	Partner Key: 53
	Partner Mac Address: 74:ea:3a:ba:35:e4

Slave Interface: eth0
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:08:9b:c4:a6:f4
Aggregator ID: 1

Slave Interface: eth1
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:08:9b:c4:a6:f5
Aggregator ID: 1


As always, there's some documentation to read: https://help.ubuntu.com/community/UbuntuBonding

Cheers,

James

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