Transparent Mode using WCCP v2

[ezekiel_ironport]

Dear All,

Greetings. Please correct me if I am wrong. When to use GRE and when to use L2 redirection is depends on the router/switch?

What are the parameters to be configured in Transparent Redirection 'Load-Balacing Method' and 'Forwarding Method' when using GRE?

Please help me to understand more on GRE and L2 redirection when in transparent mode, and configuration in S-Series.

Many Thanks,
ezekiel

[jowolfer]

Ezekiel,

L2 is the preferred method when possible, since GRE adds an extra 28 bytes of overhead. For L2 to be possible, the WSA must be directly connected to the router / WCCP device.

If the WSA is more then 1 hop away, GRE MUST be used.

The major difference between Hashing and Masking is that if Masking is supported, the router / switch will consume less CPU building the load balancing tables.

It's recommended that you set the WSA to use "Hashing or Masking". The WSA will then negotiate with the WCCP router which to use. If your router supports both, Masking is preferred.

Hope this helps.

[pirates_ironport]

Ezekiel,

L2 is the preferred method when possible, since GRE adds an extra 28 bytes of overhead. For L2 to be possible, the WSA must be directly connected to the router / WCCP device. 

If the WSA is more then 1 hop away, GRE MUST be used. 

The major difference between Hashing and Masking is that if Masking is supported, the router / switch will consume less CPU building the load balancing tables. 

It's recommended that you set the WSA to use "Hashing or Masking". The WSA will then negotiate with the WCCP router which to use. If your router supports both, Masking is preferred.

Hope this helps.

Please help regarding WCCP v2.

My company had 2 routers & 2 WSA. Each WSA is directly connected to the each router.

Can I use both WCCP L2 & GRE? If possible, can give some examples?

[pirates_ironport]

Ezekiel,

L2 is the preferred method when possible, since GRE adds an extra 28 bytes of overhead. For L2 to be possible, the WSA must be directly connected to the router / WCCP device. 

If the WSA is more then 1 hop away, GRE MUST be used. 

The major difference between Hashing and Masking is that if Masking is supported, the router / switch will consume less CPU building the load balancing tables. 

It's recommended that you set the WSA to use "Hashing or Masking". The WSA will then negotiate with the WCCP router which to use. If your router supports both, Masking is preferred.

Hope this helps.

Please help regarding WCCP v2.

My company had 2 routers & 2 WSA. Each WSA is directly connected to the each router.

Can I use both WCCP L2 & GRE? If possible, can give some examples?

[jowolfer]

Pirates,

I believe that GRE vs. L2 is negotiated per service ID. So you may not have one WSA using GRE and the other L2, when both are using the same Service ID.

Please note that not all Cisco devices support both GRE or L2. It is common for certain models of Catalyst to only support L2 and Masking, whereas most routers support GRE and L2.

GRE will always work, there are no design limitations. The only thing to be aware of is that it will utilize extra over head on the client connection to the WSA.