Re: Linux Bonding on Installation

[sandrewz <sandrewz gmail com>]

Hi Brian,

So the available LACP etherchannel modes for Cisco switches are either active or passive. Both don't seem to want to negotiate with RHEL4's mode 4(LACP). 

The problem with this is that even if it did work, come kickstart time, traffic would be sent down either of the gige ports on the node. The switch side seems to think that both gige's are activated, and it becomes a hit or miss game to determine if the only active interface (eth0) is going to receive the arp request or even the rest of the installation since the switch will try to load balance traffic even when the node isn't in a bonded configuration.


Steve

On 7/27/06, Brian Long <brilong cisco com> wrote:

sandrewz wrote:

> List,
>
> I am wondering if anyone has been able to perform an installation
> across a linux box with using an etherchannel configuration on the
> switch. I have two nics on a box that will install with a vanilla
> switch configuration, but no avail with it on. I'm using a Cat 3750
> series switch with etherchannel mode set to on. Other LACP switch
> configurations don't seem to negotiate with bonding mode 4 (LACP) on
> the linux side.
>
> Steve

From bonding.txt (and http://linux-net.osdl.org/index.php/Bonding):
"arp_interval :Specifies the ARP link monitoring frequency in
milliseconds. If ARP monitoring is used in an etherchannel compatible
mode (modes 0 and 2), the switch should be configured in a mode that
evenly distributes packets across all links."

Under the "Switch Configuration" section, it says the following wrt. mode 4:
"The 802.3ad mode requires that the switch have the appropriate ports
configured as an 802.3ad aggregation. The precise method used to
configure this varies from switch to switch, but, for example, a Cisco
3550 series switch requires that the appropriate ports first be grouped
together in a single etherchannel instance, then that etherchannel is
set to mode "lacp" to enable 802.3ad (instead of standard EtherChannel)."

Mode 4 on Linux requires you to enable 802.3ad mode on the Etherchannel
group.  Does this help?

/Brian/

--
nahant-list mailing list
nahant-list redhat com
https://www.redhat.com/mailman/listinfo/nahant-list