Forum Discussion

maadavan's avatar
maadavan
Icon for Altocumulus rankAltocumulus
Jun 05, 2023

SSL Offloading for specific IPs or range of IPs

Current flow is as below

Client -> F5 LTM (SSL Proxying) -> On premise Application Servers (TLS Offloading).

Certificates that do TLS offloading has F5 LTM DNS as CN/SAN.

For a migration of my on premise application stack to cloud, I need to achieve below two cases.

Client -> F5 LTM (SSL offloading for specific client IPs & Reencrypt TLS) -> New Stack cloud Application

Client -> F5 LTM (SSL Proxying) -> On premise Application Servers (TLS Offloading).

I have went through Bypass ssl offloading to certain IPs - DevCentral (f5.com) & SSL Offloading using iRules - DevCentral (f5.com). But not the exact case. Would wanted to confirm with experts here in thr forum please. Can someone kindly shed some light & a small example please?

application delivery
iRules
offloading
ssl
  • JRahm's avatar
    JRahm
    Jun 05, 2023

    Something like this maybe (where offload_ips is a data-group with ip host and ip/mask as specified)

    when CLIENT_ACCEPTED priority 500 {
    if {[class match -- [IP::client_addr] equals offload_ips]} {
        SSL::enable
        pool new_stack_cloud_application
    } else {
        SSL::disable
        pool on_premise_applications_servers
    }
}

     

  • Daniel_Wolf's avatar
    Daniel_Wolf
    Jun 06, 2023

    JRahm, I beg to differ and offer a different solution. Not every problem requires an iRule to be solved. 🙂
    I'd rather create two virtual servers, one with pool_A and SSL Bridging configured and another one with pool_B and SSL Passthrough, and make use of K14800: Order of precedence for virtual server matching.  

    OrderDestinationSourcePort
    1(host address)(network address)(port)
    2(host address)*(port)

    For the source you can use an Address List as described in this Manual article: Configuring Multiple IP Addresses and Service Ports for a Virtual Server. This would replace the datagroup for matching the source IP address(es).

    KR
    Daniel 

  • JRahm's avatar
    JRahm
    Icon for Admin rankAdmin
    Jun 05, 2023

    Something like this maybe (where offload_ips is a data-group with ip host and ip/mask as specified)

    when CLIENT_ACCEPTED priority 500 {
    if {[class match -- [IP::client_addr] equals offload_ips]} {
        SSL::enable
        pool new_stack_cloud_application
    } else {
        SSL::disable
        pool on_premise_applications_servers
    }
}

     

    • Daniel_Wolf's avatar
      Daniel_Wolf
      Icon for MVP rankMVP
      Jun 06, 2023

      JRahm, I beg to differ and offer a different solution. Not every problem requires an iRule to be solved. 🙂
      I'd rather create two virtual servers, one with pool_A and SSL Bridging configured and another one with pool_B and SSL Passthrough, and make use of K14800: Order of precedence for virtual server matching.  

      OrderDestinationSourcePort
      1(host address)(network address)(port)
      2(host address)*(port)

      For the source you can use an Address List as described in this Manual article: Configuring Multiple IP Addresses and Service Ports for a Virtual Server. This would replace the datagroup for matching the source IP address(es).

      KR
      Daniel 

      • JRahm's avatar
        JRahm
        Icon for Admin rankAdmin
        Jun 06, 2023

        Daniel_Wolf HOW DARE YOU BEG TO DIFFER!! 😎

        But seriously, 💯 on only using iRules where necessary. maadavan, this solution is definitely the way to go!

      • JRahm's avatar
        JRahm
        Icon for Admin rankAdmin
        Jun 05, 2023

        untested...make sure to test in a lab! if you have trouble I might be able to mock up tomorrow.