Routing

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Routing and prefix delagation

  • 1.  Routing and prefix delagation

    Posted 12-03-2020 13:53
    Hello
    We want to implement IPv6 prefix delegation to CPE (SRX300), a dhcpv6 server is locate on a server and service provider PE will act as relay dhcp, see image attached below that is showing our case.
    How can we configure SRX300 as client dhcpv6, so that SRX can allocate IPv6 to customer LAN ?
    I have configured PE as below:
    set forwarding-options dhcp-relay dhcpv6 group IPv6_CLIENTS interface <interface_name>
    set forwarding-options dhcp-relay dhcpv6 server-group DHCPv6_SERVER <DHCPv6_IPv6_address>
    set forwarding-options dhcp-relay dhcpv6 active-server-group DHCPv6_SERVER

    My last question, how can I indicate in the configuration IPv6 address that PE can use in order to send dhcpv6 sollicit message coming from SRX to dhcpv6 server ?
    Thank you for your support.
    Best regards,



  • 2.  RE: Routing and prefix delagation

     
    Posted 12-04-2020 04:49
    Hello,

    Find in the below KB an example for Configuring the SRX as a DHCPv6 client with auto-prefix delegation
    Configuring the SRX as a DHCPv6 client with auto-prefix delegation - Juniper Networks



    Regrading the PE configuration, you can c
    onfigure DHCP relay server to use the configured loopback address as the source address in both the IP header and in DHCP messages relayed to the server using "relay-source" knob
    relay-source


     
    ​I would advise you to check all possible PE configuration parameters in the below link 
    dhcpv6 (DHCP Relay Agent)



    Best wishes and Good luck,
    Bemwa


  • 3.  RE: Routing and prefix delagation

    Posted 12-05-2020 15:11
    Hello bbeshay
    Thank your for your reply. I want to share some others information in order to make good understanding.
    CPE is connected to PE-A into VRF-A, DHCPv6  is connected to PE-B into VRF-B, MPLS is running between PE-A and PE-B, IPv6 routes between VRF-A ans VRF-B are exchange without any problem, VRF-A as lo0.1 with IPv6 address, ping inet6 is OK from VRF-A source IPv6 lo0.1 address to DHCPv6 located on VRF-B.

    Then I want from DHCPv6 server point of view, customers DHCPv6 request/Sollicit come with VRF-A lo0.1 IPv6 address so DHCPv6 Server will to reply to lo0.1 of VRF-A and at his turn will deliver the reply to customers CPE.

    So my configuration is exactly this:
    set routing-instances VRF-A forwarding-options dhcp-relay dhcpv6 group IPv6_CLIENTS interface <interface_name>
    set routing-instances VRF-A forwarding-options dhcp-relay dhcpv6 server-group DHCPv6_SERVER <DHCPv6_IPv6_address>
    set routing-instances VRF-A forwarding-options dhcp-relay dhcpv6 active-server-group DHCPv6_SERVER

    I have used the option overrides relay-source like this :

    set routing-instances VRF-A forwarding-options dhcp-relay dhcpv6 overrides relay-source lo0.1

    this has not worked,  also I remarked, when I plut ? at the end of this command:

    MX-204# set routing-instances VRF-A forwarding-options dhcp-relay dhcpv6 overrides relay-source ?
    Possible completions:
    <relay-source> Interface for relay source
    fxp0
    lo0
    xe-0/0/0
    xe-0/1/0
    xe-2/0/0
    {master}[edit]

    I did not get VRF-A interfaces sub interfaces, these interfaces displayed above belongs to Master (default) routing instance.

    Please if any ideas dont hesitate to share.

    Others questions: as we want IPv6 prefix delagation, do IPv6 global address have to be setup between CPE and PE-A link ?

    Thank you.


  • 4.  RE: Routing and prefix delagation

     
    Posted 12-07-2020 06:07
    Hello,

    Your find out is Right, The interface-name must be lo0.0 ONLY!

    so you may think in other ways like below but routing changes is needed
    - replace-ip-source-with
    - DHCP Relay Proxy

    Regards,
    Bemwa


  • 5.  RE: Routing and prefix delagation

     
    Posted 12-08-2020 16:50
    @sambill

    Did Bemwa's guidance help you? I'd like to know if this is working for you now before I dig into it myself.

    Also, thank you for leaving a comment on my YouTube channel!​