Ethernet bondig

Mon Oct 8 09:39:16 UTC 2007

Hi,

here is solution for you.

..................................................................................................................................................

 Where should I use bonding?

You can use it wherever you need redundant links, fault tolerance or load
balancing networks. It is the best way to have a high availability network
segment. A very useful way to use bonding is to use it in connection with
802.1q VLAN support (your network equipment must have 802.1q protocol
implemented).
Diverse modes of bonding:

*mode=1* (active-backup)
Active-backup policy: Only one slave in the bond is active. A different
slave becomes active if, and only if, the active slave fails. The bond's MAC
address is externally visible on only one port (network adapter) to avoid
confusing the switch. This mode provides fault tolerance. The primary option
affects the behavior of this mode.

*mode=2* (balance-xor)
XOR policy: Transmit based on [(source MAC address XOR'd with destination
MAC address) modulo slave count]. This selects the same slave for each
destination MAC address. This mode provides load balancing and fault
tolerance.

*mode=3* (broadcast)
Broadcast policy: transmits everything on all slave interfaces. This mode
provides fault tolerance.

*mode=4* (802.3ad)
IEEE 802.3ad Dynamic link aggregation. Creates aggregation groups that share
the same speed and duplex settings. Utilizes all slaves in the active
aggregator according to the 802.3ad specification.

   - Prerequisites:
      - Ethtool support in the base drivers for retrieving the speed
      and duplex of each slave.
      - A switch that supports IEEE 802.3ad Dynamic link aggregation.
      Most switches will require some type of configuration to enable
      802.3ad mode.

*mode=5* (balance-tlb)
Adaptive transmit load balancing: channel bonding that does not require any
special switch support. The outgoing traffic is distributed according to the
current load (computed relative to the speed) on each slave. Incoming
traffic is received by the current slave. If the receiving slave fails,
another slave takes over the MAC address of the failed receiving slave.

   - Prerequisite: Ethtool support in the base drivers for retrieving the
   speed of each slave.

*mode=6* (balance-alb)
Adaptive load balancing: includes balance-tlb plus receive load balancing
(rlb) for IPV4 traffic, and does not require any special switch support. The
receive load balancing is achieved by ARP negotiation. The bonding driver
intercepts the ARP Replies sent by the local system on their way out and
overwrites the source hardware address with the unique hardware address of
one of the slaves in the bond such that different peers use different
hardware addresses for the server.
Also you can use multiple bond interface but for that you must load the
bonding module as many as you need.
Example:

In the /etc/modprobe.conf file add the following:

alias bond0 bonding
options bond0 miimon=80 mode=5

In the /etc/sysconfig/network-scripts/ directory create ifcfg-bond0:

DEVICE=bond0
IPADDR=<ip address>
NETMASK=
NETWORK=
BROADCAST=
GATEWAY=
ONBOOT=yes
BOOTPROTO=none
USERCTL=no

Change the ifcfg-eth0 to:

DEVICE=eth0
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
MASTER=bond0
SLAVE=yes

Change the ifcfg-eth1 to:

DEVICE=eth1
ONBOOT=yes
BOOTPROTO=none
USERCTL=no
MASTER=bond0
SLAVE=yes

That´s all! Now your trunk should be up and running with any type of switch
config.

Regards,

Linux Tech Mails

On Fri, 5 Oct 2007, Edoardo Causarano wrote:

> Hi,
>
> Your trick is nice although I'd like to remain within the second layer of
the stack. HP-UX does something similar to your setup by clustering nics and
failing over to the spare (keeping the same IP addr though); perhaps RHCS or
RH5 could do the same.
>
> As far as I've been told by the network folks, nic teaming can only be
done on a single switch (or n-stacked) although the italian wikipedia on
spanning tree does seem to imply that the algo would disable the redundant
paths keeping them as a hot backups. So, one would think that a switch
network should tolerate multiple branches.
>
> Has anyone done bonding on separate switches? Does it work? How long does
it take to restore connectivity in case of link failure? (I don't care about
bw/port loss, we're on GigE and hw to spare anyway)
>
> Ideally I'd like to work with Nortel DSMLT switches and get rid of
spanning tree altogether. (does Cisco do that or not unless over their dead
body)
>
>
> Ciao,
> e
>
> -----Original Message-----
> From: redhat-sysadmin-list-bounces at redhat.com <
redhat-sysadmin-list-bounces at redhat.com>
> To: redhat-sysadmin-list at redhat.com <redhat-sysadmin-list at redhat.com>
> Sent: Fri Oct 05 03:10:51 2007
> Subject: RE: Ethernet bondig
>
> I understand what you mean and I'd love to know that there is a real
solution out there! :)
>
> At the moment, I have multiple nics with connections to different
switches, and a dodgy perl script that tries to ping a destination via the
default route, and if it can't it then drops that interface and points the
default route to the next one in the list. It's dodgy but it works...
>
>
>
> ________________________________
>
> From: redhat-sysadmin-list-bounces at redhat.com [mailto:
redhat-sysadmin-list-bounces at redhat.com] On Behalf Of Edoardo Causarano
> Sent: Friday, 5 October 2007 10:20 AM
> To: redhat-sysadmin-list at redhat.com
> Subject: Ethernet bondig
>
>
>
> Hi there,
>
> I have a question for you. I've done some FC SAN configurations and
understood the benefits of multipathing so now our critical servers are
redundantly connected to minimize storage failure probability.
>
> Can I do the same with network? I'd like to bond a couple eth devs and
attach them to redundant switches (not stacked) so in case one link fails,
the other one keeps connectivity (throw in some load balancing as a bonus!)
>
> As far as I can understand, and as the network guys put it, it can't be
done. In fact, eth bondig replicates the mac address on all the
participating interfaces confusing the hell out of the eth routing
protocols. Still, I keep wondering about this issue... after all,  having to
rush out to the datacentre because a nic, cable or switch gave up the ghost
while everything else is duplicated is irritating (and inelegant).
>
> So, would the switches (Cisco, in our case) choke is the same MAC was
detected on two different ports of two different units? Would they go in
broadcast mode, flooding the VLAN?
>
> All this on Linux servers... Of course ;-)
> e

-- 
Regards,

Linux Tech Mails Group.
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