WAAS Design Help Needed - URGENT!

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Sep 5th, 2010
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Hi,


I am currently designing and implementing a WAAS solution for s client in their Data Center. It is deployment of a single Accelerator and one CM.


It has been decided that the WAAS accelerator (7341) will have its two NICs connected to two of their core switches (both 6500). The two core switches have a Layer 3 Etherchannel link between them and are running OSPF for network convergence (i.e. Layer 2 connectivity is not used).


I am facing a problem in the design, since I know that the Active/Standby configuration for the accelerator would require a redundant gateway via HSRP (at least) but this is not possible in a routed environment in the core switches. Furthermore, I am to run WCCPv2 for redirection.


Therefore, I am confused as to how to proceed in such a case considering that I can only configure one default gateway on the accelerator when I need high availability on two different subnets.


Please assist at your earliest.


Thanks.

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wrobbin Wed, 09/22/2010 - 10:21
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Is the Link between the 6500 a VSS link ? reason I ask is technicality a VSS is a layer 3 routed port channel ?

Amir Aziz Sat, 09/25/2010 - 02:39
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No, the link is a routed link using OSPF. However, I have managed to prepare a trunk link that allows only the WAAS VLAN and it seems to have corrected the problem. Yet, I am still wondering if thisis the correct design.


Regards,


Amir

ahskhan Sat, 09/25/2010 - 05:53
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  • Cisco Employee,

Amir,


   Considering your question below


"I am facing a problem in the design, since I know that the Active/Standby configuration for the accelerator would require a redundant gateway via HSRP (at least) but this is not possible in a routed environment in the core switches. Furthermore, I am to run WCCPv2 for redirection."


Do WAE is configured for Standby interface and is this your Primary Interface as well? If answer is yes then see below


You will need a common VLAN for WAAS on both 65K swicthes in order for Active / Standby interface to work properly.


1: When using OSPF make sure your tcp flows has both ingress and egress flows transit from same switch

2: Use Generic GRE method for Egress under WAAS intercept configuration.



Since you are running WCCP each swicth will be able to redirect its TCP traffic via GRE Tunnel to WAAS and WAAS will send the packet back to the same swicth. This will ensure packet path is not modified when WAAS / WCCP is introduced.


Also make sure that you do not have any WCCP redirect on Layer 3 connection between 2 swicthes. Let me know if this helps.


Ahsan Khan

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