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Frank_30530
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Jun 22, 2018

Difference between VS: L3 forwarding, FastL4 (with pool, with nexthop, with transparent nexthop)

I'm trying to find out what the differences are between the following.

 

Consider a BIG-IP in L3 mode (multiple VLANs: internal, external).

 

Consider a wildcard VS (e.g., destination 10.0.0.0/16, port: *, protocol: any).

 

  1. Forwarding-IP VS.
  2. Performance L4, with a regular (default) 'Pool' defined as gateway.
  3. Performance L4, with a 'Last Hop Pool' defined.
  4. Performance L4, with a 'Transparent Nexthop' defined.

1 Reply

  • Hello,

     

    • Forwarding-IP VS: destination 10.0.0.0/16, port: *, protocol: any

    That's mean, that your VS will accept all traffic that matches with 10.0.0.0/16:* and forwards it to the destination IP address that is specified in the request rather than load balancing the traffic to a pool. Address translation is disabled when you create an IP forwarding virtual server, leaving the destination address in the packet unchanged.

     

    • Performance L4, with a regular (default) 'Pool' defined as gateway.

    A Performance (Layer 4) virtual server increases the speed at which the virtual server processes packets. So if you set your VS to 0.0.0.0/16, port: *. And as you told you want to Consider a BIG-IP in L3 mode. You have to set a pool with your GW and on the VS you have to uncheck Address Translation and Port Translation in your VS. because user request don't have to be nated to GW IP... More you pool have to be set with GW witout port (set at wildcard) that's the reason why you have to uncheck Port Translation in your VS.

     

    • regarding 'Last Hop Pool', this feature ensures that traffic is sent back via the same hop from which it was sent to the bigip. This is accomplished by the F5 forwarding, THE RETURN TRAFFIC, to the MAC address it came from. The traffic source MAC address is recorded within the connection table along with the source and destination addresses.

    https://devcentral.f5.com/questions/deployment-guide-auto-last-hop-and-auto-last-pool-52978

     

    Hope it's clear for you