Hi,
I am trying to find out what provides the best availability and reliability.

I have two ethernet adapters connected through two different Cisco (6500)
switches.
It looks that Etherchannel requires a connection through 1 switch, or the
(NIB) primary / backup adapter option.
Last option does not provide load balancing.

Virtual Ethernet seems a good alternative, but requires three ip-adresses in
the same subnet.

Any goo ideas or possibilities on AIX 5.3 and Cisco 6500 ?

Thank IA
JW

Le Mon, 06 Feb 2006 17:55:24 +0100, JW a écrit*:

> Hi,
> I am trying to find out what provides the best availability and reliability.
>
> I have two ethernet adapters connected through two different Cisco (6500)
> switches.
> It looks that Etherchannel requires a connection through 1 switch, or the
> (NIB) primary / backup adapter option.
> Last option does not provide load balancing.
>
> Virtual Ethernet seems a good alternative, but requires three ip-adresses in
> the same subnet.
>
> Any goo ideas or possibilities on AIX 5.3 and Cisco 6500 ?
>
> Thank IA
> JW

We use another possibility with only one IP and two switchs on AIX 5.2:

en0 -> Primary interface
en2 -> Backup interface
en4 -> The new interface which is composed of both

The switch when we lost one interface is very speedy (only very few packed
dropped for a ping)

Regards,

JYL

"JW" <janwillem.delange@nospam.tiscali.nl> wrote in message
news:43e77f8e$0$754$5fc3050@dreader2.news.tiscali. nl...
> Hi,
> I am trying to find out what provides the best availability and
> reliability.
>
> I have two ethernet adapters connected through two different Cisco (6500)
> switches.
> It looks that Etherchannel requires a connection through 1 switch, or the
> (NIB) primary / backup adapter option.
> Last option does not provide load balancing.
>
> Virtual Ethernet seems a good alternative, but requires three ip-adresses
> in the same subnet.
>
> Any goo ideas or possibilities on AIX 5.3 and Cisco 6500 ?

Something we do is to use a set of stacked Ciscos (3750). You can
etherchannel across
the stack and get redundancy without "wasting" an adapter as a backup that
will never get used.
You need to use the "classic" etherchannel mode (non-LACP) to allow the
etherchannel to
survive a switch failure.
Don't know if you can stack 6500s.

"Steve Greatbanks" <steve_greatbanks@hotmail.com> schreef in bericht
news:dsa1f7$2tsg$1@otis.netspace.net.au...
>
> "JW" <janwillem.delange@nospam.tiscali.nl> wrote in message
> news:43e77f8e$0$754$5fc3050@dreader2.news.tiscali. nl...
>> Hi,
>> I am trying to find out what provides the best availability and
>> reliability.
>>
>> I have two ethernet adapters connected through two different Cisco (6500)
>> switches.
>> It looks that Etherchannel requires a connection through 1 switch, or the
>> (NIB) primary / backup adapter option.
>> Last option does not provide load balancing.
>>
>> Virtual Ethernet seems a good alternative, but requires three ip-adresses
>> in the same subnet.
>>
>> Any goo ideas or possibilities on AIX 5.3 and Cisco 6500 ?
>
> Something we do is to use a set of stacked Ciscos (3750). You can
> etherchannel across
> the stack and get redundancy without "wasting" an adapter as a backup that
> will never get used.
> You need to use the "classic" etherchannel mode (non-LACP) to allow the
> etherchannel to
> survive a switch failure.
> Don't know if you can stack 6500s.
>
>

Steve,
Sounds Oké, two adapters really in use and good failover
If this works on 3750 it should be Oké on 6500 also.
With "classic" you mean two equivalent roles for the adapters, and No
primary/secondary I assume?
Rather a sort of creating a link aggregation with twice the bandwidth?
Jan Willem

"JW" <janwillem.delange@nospam.tiscali.nl> wrote in message
news:43e89fd8$0$749$5fc3050@dreader2.news.tiscali. nl...
> "Steve Greatbanks" <steve_greatbanks@hotmail.com> schreef in bericht
> news:dsa1f7$2tsg$1@otis.netspace.net.au...
>>
>> "JW" <janwillem.delange@nospam.tiscali.nl> wrote in message
>> news:43e77f8e$0$754$5fc3050@dreader2.news.tiscali. nl...
>>> Hi,
>>> I am trying to find out what provides the best availability and
>>> reliability.
>>>
>>> I have two ethernet adapters connected through two different Cisco
>>> (6500) switches.
>>> It looks that Etherchannel requires a connection through 1 switch, or
>>> the (NIB) primary / backup adapter option.
>>> Last option does not provide load balancing.
>>>
>>> Virtual Ethernet seems a good alternative, but requires three
>>> ip-adresses in the same subnet.
>>>
>>> Any goo ideas or possibilities on AIX 5.3 and Cisco 6500 ?
>>
>> Something we do is to use a set of stacked Ciscos (3750). You can
>> etherchannel across
>> the stack and get redundancy without "wasting" an adapter as a backup
>> that will never get used.
>> You need to use the "classic" etherchannel mode (non-LACP) to allow the
>> etherchannel to
>> survive a switch failure.
>> Don't know if you can stack 6500s.
>>
>>
>
> Steve,
> Sounds Oké, two adapters really in use and good failover
> If this works on 3750 it should be Oké on 6500 also.
> With "classic" you mean two equivalent roles for the adapters, and No
> primary/secondary I assume?
> Rather a sort of creating a link aggregation with twice the bandwidth?
> Jan Willem

By "classic" I mean the default ("standard") etherchannel mode which does
not use LACP.
When you make an etherchannel (smitty etherchannel), you don't want the
802.3ad or "round robin" mode. You need to define a channel group on
the switch stack (so you explicitly define which ports constitute the
etherchannel).
As you note, you get the redundancy benefits because your NICs are in
multiple
physical switches, and the stack can survive switch failures, and you get to
use all
of your NICs so you get all of the available bandwidth. You can still use a
backup
adapter in addition to this, but we didn't see the benefit.

This is exactly what I want to implement. The question is:
1. The two switches don't necessary be etherchannel supported.
2. We don't need configure anything on both switches.
3. Do we need a dedicated link between the two switches? Or the two
switches link to another switch and can ping each other only?

Thanks,

AS

> We use another possibility with only one IP and two switchs on AIX 5.2:
>
> en0 -> Primary interface
> en2 -> Backup interface
> en4 -> The new interface which is composed of both
>
> The switch when we lost one interface is very speedy (only very few packed
> dropped for a ping)
>
> Regards,
>
> JYL

This is exactly what I want to implement. The question is:
1. The two switches don't necessary be etherchannel supported.
2. We don't need configure anything on both switches.
3. Do we need a dedicated link between the two switches? Or the two
switches link to another switch and can ping each other only?

Thanks,


AS