Re: Running Alteon back into another switch

Hello.

You have a lot of solutions, some examples follow :

- put the servers in the same vlan as the Virtual IP of the virtual servers owned by the alteon and use client nat to force the return traffic to go through the alteon (but you lose the real source ip addresses of the clients, as they arre NAT'ed now). In this case only one vlan is needed.

- Use the IP of the alteon as default gateway of the servers, so return traffic goes back to the alteon and the vlan is routed on the alteon.

In all cases the catalyst is used in L2 fowarding, in your case you plugged the servers in vlan 60, what is the default gateway defined ont the servers ? if it's not the alteon or if you don't use client nat, return traffic enters the switch and frames are L2 forwarded to the external gateway, if the vlan is routed on the 6500, frames are routed directly by the switch, bypassing the alteon box.

regards,

Surya



--- En date de : Lun 30.3.09, Alex Thurlow <[email protected]> a écrit :
De: Alex Thurlow <[email protected]>
Objet: Re: [load balancing] Running Alteon back into another switch
À: "Load Balancing Mailing List" <[email protected]>
Date: Lundi 30 Mars 2009, 17h27

Thanks for letting me know my options.  I was under the impression that 
by having the load balanced servers on a separate vlan on the 6506, I 
was effectively making the traffic have to go back through the Alteon. 
Is this not the case?

On 3/27/2009 6:43 PM, Tony Bourke wrote:
> Hi Alex,
>
> I think the missing piece is one of the fundamentals of load
> balancing: You need to make sure traffic goes through the Alteon on
> the way out.
>
> Traffic for load balanced servers needs to hit the load balancer on
> the way, and on the way out.  Getting traffic to hit the LB on the way
> in is easy; the VIP address.  Getting traffic through the LB on the
> way out, that's a bit trickier, and you have several options.
>
> By plugging servers directly into the Alteon, you were forcing traffic
> through the Alteon on the way out by it being the server's only
> network connection.  Now that you're plugging the servers into the
> 6500, you'll need another method.
>
> If you want to be able to hit the Virtual Service on the Alteon while
> on the same subnet as the servers, you'll have to use proxy IPs
> (warning, this will make it appear to the web servers that all inbound
> web requests come from the Alteon, instead of the true source IP
> address).  By making all requests come from the Proxy IP (PIP) of the
> Alteon, you force traffic through the Alteon on the out.
>
> If you don't have that limitation, i.e. your clients will be on a
> different netblock than the servers, you can use route-path mode by
> setting the default gateway of the servers to the Alteon's floating
> administration IP.  This makes the Alteon the path of traffic on the
> way out, and set the Alteon's default gateway to whatever the
server's
> default gateway used to be, so traffic still makes it out to the
> Internet.
>
> So in short, you're options are:  Proxy IP, or route-path (default
> gateway is the Alteon).
>
> Hope that helps, and let me know if you have any questions.
>
> Tony
>
>
>
>
> When you were plugging the servers directly into the Alteon.
>
>
> On Mar 27, 2009, at 3:23 PM, Alex Thurlow wrote:
>
>
>> I have an issue which is somewhat of a general networking question,
>> but
>> there's a load balancer in the middle of it, so I'm asking
here.
>>
>> Here's my current setup:
>>
>> A Cisco 6506 has all of my non-load balanced hardware and my uplinks
>> plugged into it.  All general ports  are on VLAN 10
>>
>> 2 bonded Fiber links from the 6506 to an Alteon 184.
>>
>> 3 load balanced machines plugged directly into the Alteon.  All Alteon
>> ports are also VLAN 10
>>
>> All this works.
>>
>> What I want to do is, instead of plugging the load balanced machines
>> directly into the Alteon, I want to run a link from the Alteon back to
>> ports on the 6506 on different VLANs.  Then I can plug as many things
>> behind the load balancer as I want as long as I don't go over the
>> bandwidth supplied by the links to the alteon and back.
>>
>> I've been testing this however, and it's not as easy as it
seems
>> like it
>> should be.
>>
>> I set 2 ports on the 6506 to:
>> switchport
>> switchport access vlan 60
>> switchport mode access
>> no cdp enable
>>
>> I plugged port 6 (not doing vlan tagging) on the Alteon into one of
>> the
>> vlan 60 ports on the 6506 and I plugged a test machine into the other
>> vlan 60 port.
>>
>> I set up a real server on in the Alteon with the IP address of the
>> test
>> machine.
>>
>> After all this, the test machine can access the Alteon and any
>> machines
>> connected directly to it, but it can't contact the 6506 or any
>> machines
>> hooked to it.
>>
>> Another note, all machines here are using IP addresses in the same C
>> block, if this matters.  Direct Access Mode on the Alteon is on as
>> well,
>> so things should be able to access its IP directly.
>>
>> Anyone know what I'm missing here?
>>
>> --
>> Alex Thurlow
>> Blastro Networks
>>
>> http://www.blastro.com
>> http://www.roxwel.com
>> http://www.yallwire.com
>>
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> _______________________________________________
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>


-- 
Alex Thurlow
Blastro Networks

http://www.blastro.com
http://www.roxwel.com
http://www.yallwire.com

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