Re: bond interface arp, vlan and trunk / network question

From: stefan novak
Date: Mon Apr 20 2009 - 16:01:10 EST


>> nic1 --trunk--> bladesw1 --trunk--> backbone switch
>> nic2 --trunk--> bladesw2 --trunk--> backbone switch
>>
>> So far vlan and trunking works as expected. But if one trunk
>> connection from a bladeswitch to the backbone switch is down the
>> mii-tool cant recognize this.
>
> What is the exact problem on this one ?

The exact problem is that the bonding driver don't switch the
interface because the mii-tool don't recognize that the connection
between the two switches is now broken.

nic1 --trunk--> bladesw1 --trunk--> backbone switch (passive if)
nic2 --trunk--> bladesw2 --xxx--broken-trunk-xx-> backbone switch (active if)

> Sufficiently recent versions of bonding should VLAN tag the ARP
>probes, provided you are using a VLAN device configured above the bond.
>My recollection is that VLAN tagging of ARP probes was added about three
>years ago.
>
> If the switch port is configured as native to a VLAN, then it
>should tag everything coming in.
>
> As Eric asks, what are you running?

I've got a bonding interface over eth0 and eth1 and on that bonding
interface several vlans. The arp probe is in vlan 600 and i can ping
it from the bash.
Also a arpping with -I bond0.600 is working. Arpping with -I bond0 is
not working.
So the arp check is not working for me :(

the nic driver is:
alias eth0 igb
alias eth1 igb

the bond setiings:
cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.2.4 (January 28, 2008)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: eth0
MII Status: up
MII Polling Interval (ms): 0
Up Delay (ms): 0
Down Delay (ms): 0
ARP Polling Interval (ms): 30
ARP IP target/s (n.n.n.n form): 172.21.0.254

Slave Interface: eth0
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:30:48:94:7d:1a

Slave Interface: eth1
MII Status: up
Link Failure Count: 0
Permanent HW addr: 00:30:48:94:7d:1b


On Mon, Apr 20, 2009 at 8:37 PM, Jay Vosburgh <fubar@xxxxxxxxxx> wrote:
> Eric Dumazet <dada1@xxxxxxxxxxxxx> wrote:
>
>>stefan novak a écrit :
>>> Hello list,
>>>
>>> I've got a Problem with my bladecenter and bond interfaces.
>>> My Server has 2 interface, each on a seperate switch. Each
>>> serverinterface is connected via a trunk to one of the switches.
>>> Each switch has a trunk to stacked-backbone switch.
>>>
>>> nic1 --trunk--> bladesw1 --trunk--> backbone switch
>>> nic2 --trunk--> bladesw2 --trunk--> backbone switch
>>>
>>> So far vlan and trunking works as expected. But if one trunk
>>> connection from a bladeswitch to the backbone switch is down the
>>> mii-tool cant recognize this.
>>
>>What is the exact problem on this one ?
>
>        This is the expected behavior, the external switch to
> bladecenter switch (ESM) link status does not affect the ESM to blade
> link status.
>
>        Unless... your ESM supports "trunk failover."  I believe the
> Cisco ESMs do, I'm not sure about others.  With trunk failover enabled,
> loss of link on an external switch port will in turn drop link on the
> corresponding internal switch ports.  There is a long-ish delay for
> this, on the order of 750 ms, as I recall.
>
>>> I tried to use an arp target on the backbone switch to check the
>>> connection state.
>>>
>>> Now i'm running into problems. :(
>>> My bladesw1 is configured with a trunk and a private vlan id of 600.
>>> On the backbone switch is a server in the vlan 600 connected, but i
>>> can't get an arp request.
>>>
>>> What can be the problem, or is it possible to add a vlan tag on the arp check?
>>>
>>
>>What driver is in use on your NIC interface ?
>>
>>Could you post your bonding settings ?
>>
>>cat /proc/net/bonding/bond0
>
>        Sufficiently recent versions of bonding should VLAN tag the ARP
> probes, provided you are using a VLAN device configured above the bond.
> My recollection is that VLAN tagging of ARP probes was added about three
> years ago.
>
>        If the switch port is configured as native to a VLAN, then it
> should tag everything coming in.
>
>        As Eric asks, what are you running?
>
>        -J
>
> ---
>        -Jay Vosburgh, IBM Linux Technology Center, fubar@xxxxxxxxxx
>
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