Mitel IP System DHCP Issues

Discussion in 'VOIP' started by Dragon8, Feb 18, 2004.

  1. Dragon8

    Dragon8 Guest


    We have started to implement a MItel solution using 3300ICP
    controllers and 5201,5215 and 5220 handsets. Our network design is 2
    w2k DHCP servers with multiple scopes set up and split over the 2
    servers these include all the voice and data scopes. we have multiple
    stub vlans setup through 2 layer 3 switches (Allied Telesyn Rapiers)
    with Layer 3 interfaces on each vlan to allow routing between the
    vlans all vlans come back to the same to servers for DHCP using the IP
    Helper setup on the Rapiers.

    The problem is with the phones hanging at boot the boot method is
    below this is taken from the Mitel site

    This is the normal sequence of events for a dual port IP Phone, where
    VLANs are implemented:
    Power up
    Run ‘Boot' code
    Request IP address (untagged) through DHCP
    Receive IP address from default VLAN (data VLAN) and specific phone
    and system options
    Check VLAN information
    Relinquish IP address (untagged)
    Request IP address on voice VLAN (tagged)
    Receive IP address from voice VLAN and specific phone and system
    again Check VLAN information matches, if not repeat until it is.
    Locate TFTP server
    Get running code
    Register with call control
    The phone does a double fetch of information, so it is important to
    have the same VLAN and priority information in the DHCP server
    associated with the data VLAN as it is for the DHCP server associated
    with the voice VLAN, i.e. copy the option data. The engineering
    guideline that can be highlighted here is that this sequence works
    with either multiple DHCP servers on each VLAN, or that the
    router/Layer3 switch connecting the VLANs has DHCP forwarding

    the phone will receive 2 DHCP offers from the data scope (
    (1 from each server) it will then request one of the addresses and
    then release it and move to the voice vlan where it will do a DHCP
    discover and receive another 2 offers from the voice scope
    ( from each server)

    the offers that the servers are making depend on which server issued
    the first address on the data vlan if the address is taken by the
    phone then the server will allocated the correct address for the voice
    vlan. however the address that was not taken from the 2nd DHCP server
    will be reused on the voice vlan even though it is from the wrong


    phone - discover
    server1- offer
    server2- offer
    phone - request
    server1 - dhcpack
    phone - release (phone then moves to voice vlan and dhcp is routed
    through rapier using IP Helper

    phone- discover
    server2 -offer
    server1- offer
    phone- request
    server2- DHCPNACK ( this causes the phone to hang)

    I know this is long and complicated and if you have read as far as
    this thanks a lot but I could really do with some help on this


    James Howie CCNA
    Dragon8, Feb 18, 2004
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  2. Dragon8

    DPGumby Guest

    I'm no expert and I have never used two DHCP servers on one VLAN, so I don't
    know how much help I will be.

    The boot sequence looks good although I thought it was DHCP discover,
    receive IP address from DHCP server along with opt 3 ( router IP address ),
    option 128 (TFTP server address ), option 129 (RTC address on 3300 ), opt
    130 MITEL IP PHONE, opt 132 Priority and opt 133 VLAN ( usually the same
    VLAN that contains the 3300 ) . The phone looks for option 130 and if not
    exactly as shown drops address and goes into DHCP discovery again and again
    until it gets MITEL IP PHONE. If option 130 is correct then it compares the
    IP address it receives with the IP address of the RTC to see if they are on
    the same subnet. If they are not it drops all but the VLAN and priority and
    issues DHCP discovery again. This time the DHCP discovery should be issued
    on the voice VLAN.

    This is where I get a bit confused on the routing etc ( in general not with
    what you have done ). I thought the IP helper at layer 3 would send the DHCP
    request back over to the data VLAN and the original DHCP servers. That DHCP
    servers would see the request as coming from the 10.1.200.x subnet and would
    then send back an IP address from that scope rather then the 192.x.x.x
    scope. The phone would then see the 10.1.200.x address and all of the above
    options from the DHCP server. It would check option 130 as above and compare
    its address with the RTC address and should be happy. Next it would contact
    the TFTP server for the boot code and then contact the RTC to register. At
    that point it should work.

    Hmmm!I don't know. If the phone receives an offer of a 10.1.200.x address
    and a 192.168.1.x address and accepts the 192.168.1.x address is the hang
    due to the fact the phone now has 192.168.1.x as an address and it can't see
    the TFTP server or RTC addresses which should be 10.1.200.x addresses. I
    would think though it should reject the 192.168.1.x address and try again
    until it gets a 10.1.200.x address.

    Anyway I'll ask around for ideas.
    DPGumby, Feb 19, 2004
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  3. Dragon8

    Guest Guest

    The sequence in the first reply sounds correct. We've put in a number of the
    Mitel 3300 but usually have the server DHCP on VLAN1 and use the 3300 as the
    DHCP on VLAN2. I can see the phone getting confused when it reboots and
    request an IP address on VLAN2 put gets a response from VLAN1, even if it
    isn't a valid address. You might want to reconfigure the network so that the
    300 is providing DHCP to VLAN2 for the phones. You know what they say Keep
    it Simple.
    Guest, Feb 19, 2004
  4. Dragon8


    May 4, 2009
    Likes Received:


    Did you finally manage to work your Mitel ICP over Allied Telesyn Rappier Switches using the Helper command??

    I tried the Helper command but never made it to work, I had to use the ADD BOOTP RELAY=<IP of my DHCP Server> instead.

    How did you make it to work with the Helper??? What port(s) did you specify, 67, 68????


    danramirez, May 6, 2009
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