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Long dhcp lease clearing. Stuck in RELEASE state

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  • 1.  Long dhcp lease clearing. Stuck in RELEASE state

    Posted 07-30-2019 23:27


    When executing command

    clear dhcp server binding

    In most cases lease is not fade away immediatly and time varies from 5 to 7 minutes to completly remove lease.     132696869   00:0f:ea:5e:28:8d  363         RELEASE    ae0.3222028424

    The maximum lease time is 10 minutes. All leases are subscriber manager clients so the network-services enhanced-ip turned on.

    rfc3203 doesn't turned onSmiley Happy

    > show configuration system services dhcp-local-server 
    traceoptions { ## Warning: 'traceoptions' is deprecated
        file dhcp.log size 5m files 5;
    pool-match-order {
    overrides {
    group internet {
        authentication {
            password coolPassw0rd;
            username-include {
                delimiter "@";
                option-82 circuit-id remote-id;
        dynamic-profile dhcp-local-server-profile;
        access-profile external-radius;
        interface ae0.0;
        interface ae1.0;
    interface ae2.0;
    interface ae3.0; }

  • 2.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 08-06-2019 08:01

    Hi !


    RELEASE is a valid state. It means that client is releasing the IP. Means MX is waiting for an ACK from client that the IP is rleased and can be assigned it to someone esle. 

    • RELEASE—Client is releasing IP address lease.

    It mostly depends on the router/ device that is getting the DHCP IP.


    you can do "monitor traffic interface <> deatail" to see what is happeninging once you issue the command to clear binding.  




  • 3.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 08-08-2019 05:12

    I know that it is valid state but I can not understand why time varies so much.

    I was trying to disable vlan facing BRAS so all clients cannot reach device but it shows different release times.

    Thank for explanation,  I'll try to test with "well known" client router.

  • 4.  RE: Long dhcp lease clearing. Stuck in RELEASE state
    Best Answer

    Posted 08-08-2019 06:46



    Just to add "remove-when-no-subscribers" removes the VLAN once all the subscribers under the VLAN has been logged out. 




    But in our case the IP itself is not released so subscriber is still online as per BRAS. 


    May be you can collect following :

    - Log out  the subscriber.

    Monitor the following : 

     1) show subscriber extensive (check if its not in terminating for long time, if its in terminating then its probably JUNOS who is taking time)


    2) show interface <subscriber interface> .Check if the traffic (in/out packets are inccreasing)


    3)  "monitor traffic interface <> deatail" .Do this for both subscriber interface , VLAN interface and the IFD (xe- or ge- or ae- interfae) 


    Also share your config if possible.


    (Note : Kudos are always appreciated)




  • 5.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 08-08-2019 11:35

    Thanks for your reply,

    I can share config it's not a secret:

    > show configuration interfaces ae20
    auto-configure {
        vlan-ranges {
            dynamic-profile vlan-autosense-profile {
                accept dhcp-v4;
                ranges {
                } } }
    encapsulation flexible-ethernet-services;
    aggregated-ether-options {
        load-balance {

    Remove when no subscribers is turned on.

    By the way I am using single vlan tagging not stacked vlans model.


    I'll do testing what you proposed to me and share results (I should select time to not disturb my customers too much), thanks.

  • 6.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 08-17-2019 07:19
      |   view attached

    Because I'm not using QinQ scheme I've clear all dhcp addresses in vlan.

    Thaere are up to 6 addresses stuck in RELEASE state.

    Monitor traffic with

    monitor traffic interface demux0.3221368208 detail    


    shows nothing.

    Next command shows


    show interfaces ae20.3221367934 

    That some input/output packets counters are raising.



    lease_slow.txt   8 KB 1 version

  • 7.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 08-19-2019 08:24

    Hi Schadel !


           I was under the impression that ae20.3221367934 is your subscriber interface but it seems that this is the vlan interface. 

           And the subscriber inteave is demux0.3XXXXXXX.

          (Please confirm if my understanding is correct or not)      

          Please attach the complete configuration , it seems that somethings are messed up. 


        Also please share :

    show subscriber extensive interface <ae20.3221367934 or similar>

    show subscriber extensive interface <demux0.3XXXXXXX >




  • 8.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 08-22-2019 00:50



    Yes you are absolutely right, this dynamic interface binded to one vlan.

    And I've included BRAS part of the configuration.


    Thanks in advance.


    show_ifs.txt   2 KB 1 version
    jun_bras_config.txt   3 KB 1 version

  • 9.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 08-22-2019 08:21

    Hi !


     Thanks for sharing the data !

    Your config looks fine. I'm worndering that its the 3 service profiles that are taking some time in clean up. 


    For Data points , please try the following :


    (1) Logout a subscriber using "clear dhcp server binding <>" and collect following multiple time till the subscriber is gone :

    show subscribers extensive <>

    show network-access aaa subscribers username <username> (you will get the user from "show subscribers extensive" >

    show network-access aaa subscribers session-id detail <session-id> (you will get the session id from "show subscribers extensive" >



    (2) also try clearing a user IP using the follwing command :


    clear network-access aaa subscriber username <username >


    clear network-access aaa subscriber session-id <session-id>

    Now check the binding and see if it cleared soon or not ?




  • 10.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 09-24-2019 14:46
      |   view attached

    During maintanance window I've done test you have told me.

    All my service stuch in Service State: SvcVolAcctFinalWait


    Looks like accounting is a problem, am I right?

    Full listing in attachment file.


    long_dhcp_clear.txt   11 KB 1 version

  • 11.  RE: Long dhcp lease clearing. Stuck in RELEASE state

    Posted 09-26-2019 07:46

    Its not actually accounting problem , it seems that process is taking some time to clean up multiple service session attached to this subscriber. 


    Once susbcriber is logged out ; accounting stop is send to radius (for each service session) and a response is required for MX (for each service session) to clean the subscriber.


    Not sure why its taking this much time.


    Please file a JTAC case to get this investigated.