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DHCP Between Firewall Contexts

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  • DHCP Between Firewall Contexts

    Hi. We have a 6509 with 5 FWSM security contexts, Context1 through Context5. We have a DHCP server behind Context1. What we want to do is allow DHCP through the contexts.

    1. All of the contexts are set up for DHCP relay. All of the outside interfaces are configured for DHCP relay (except on Context1). All of the inside interfaces are configured for DHCP relay server. DHCP relay server address is also configured for the outside interfaces.

    2. Each of the outside and inside interfaces of each contexts are in separate VLANs. For example, VLAN 5 for the outside int on Context1 and VLAN 6 for the inside int on Context1, etc.

    As I understand it, the contexts forward traffic to the router to go to the destination and therefore we need to configure DHCP on the router itself.

    3. We configured ip helper-address on the outside interface VLANs for all 5 contexts in the router.

    Obviously this isn't working and frankly I'm confused about this set up. Any ideas? Thanks...

  • #2
    Re: DHCP Between Firewall Contexts

    If you can draw me a diagram of layer 3 (showing each firewall context) and of layer 2, I'll try and help. I think I follow.
    Brian Desmond
    Microsoft MVP - Directory Services


    • #3
      Re: DHCP Between Firewall Contexts

      ip helper-address command wasn't needed on the router. An ACL between the contexts solved the problem.