ACE - DNS load balancing

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Sep 25th, 2007
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I have to loadbalance DNS requests.

I tried to start a configuration but I didn't find anything about L3-4 load balancing or maybe I didn't understand it. I only found L7 http or ftp load balancing.

I issued this :

class-map match-any L4_DNS

description "Match traffic for DNS VIP on tcp port 53"

2 match virtual-address xx.xx.xx.xx tcp eq domain

policy-map type loadbalance first-match L7_DNS_SLBPolicy

description "Load balancing Policy"

class class-default

serverfarm DNSSrvs

policy-map multi-match L4_DNS_SLBPolicy

class L4_DNS

loadbalance vip inservice

loadbalance policy L7_DNS_SLBPolicy

loadbalance vip icmp-reply active

loadbalance vip advertise active

I am not sure this will work...

Does anybody have an idea or a valid L3-4 loadblancing configuration for ACE ?


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Overall Rating: 4 (1 ratings)
Gilles Dufour Tue, 09/25/2007 - 08:41
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why do you think this is l7 ???

this is a standard l4 rule.

It should work.


deephazz02 Tue, 09/25/2007 - 09:05
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I was confused. i read this in the Documentation:

loadbalance first-match :

Specifies a Layer 7 policy map that defines Layer 7 HTTP server

load-balancing decisions. The ACE executes the action for the first

matching classification. For a list of classes in a policy-map, the

actions associated with the first class that matches the packet are the

actions that the ACE executes on the packet. For information about

the commands in policy map load balance configuration mode, see

the ?Policy Map Load Balancing Configuration Mode Commands?


But maybe I didn't understood the concept of a Layer 7 policy map.


Gilles Dufour Tue, 09/25/2007 - 23:55
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actually the documentation and the config hint are both confusing because they call everything L7.

But the config is correct and L4.



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