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waveruh
waveruh
New Member
January 8, 2011
Question

dhcp reserved-address doesn' t work

  • January 8, 2011
  • 4 replies
  • 5796 views
Hi! I have problem with reserved-address in dhcp. I configured my FG that: DHCP Server config system dhcp server edit " Int_dhcp" set default-gateway 172.3.56.1 set dns-server1 123.456.12.45 set dns-server2 194.204.152.34 set dns-server3 194.204.159.1 set domain " woo.dra.pl" set interface " internal" set lease-time 518400 set netmask 255.255.255.0 set start-ip 172.3.56.200 set end-ip 172.3.56.250 next end and reserved-address: configure system dhcp reserved-address edit " nick1" set ip 172.3.56.12 set mac 00:34:ca:4c:7f:3a set type regular next edit " nick2" set ip 172.3.56.14 set mac 00:34:ca:4c:7f:3b set type regular next .... end I have the following problem: When I try to connect to the internal interface FortiGate, I get address 172.3.56.200. I have mac address 00:34:ca:4c:7f:3a in my notebook. I should get address 172.3.56.12. What am I doing wrong. I reserved 48 addresses. My FortiGate is FGT80C with Firmware Version: 4.0.0

    4 replies

    ede_pfau
    SuperUser
    ede_pfau
    SuperUser
    January 9, 2011
    Hi, and welcome to the Forums! Reserved addresses have to be part of the DHCP scope - .12 is not. Your notebook still does DHCP but its request is always answered with the reserved IP. Your reserved IPs are not part of the DHCP range so they are never offered. Just change the starting IP of the DHCP server to 172.3.56.12, or move your reserved IPs to be >= .200.
    waveruh
    waveruhAuthor
    New Member
    January 9, 2011
    Thanks. It' s work :)
    jtfinley
    jtfinley
    New Member
    January 14, 2011
    I did that my first time also. A habit from Cisco, they allow the reservation of an address outside the scope which if you think about it is dumb. A DHCP reservation should be for an address with in the scope hence reservation - dumb Cisco. You wouldn' t reserve a hotel room and expect to stay at a different hotel? --Joe
    A
    Anonymous_User
    Contributor
    February 16, 2011
    Thanks ede_pfau for your clarify! I am curious how one reserved-address (IP) is in case of there are several dhcp servers, one dhcp server per interface. Let say there are four internal interfaces, each interfaces has assigned on separated subnets and the reserved-address (IP) is assigned in fourth interface and it is in range of fourth dhcp server. The Fortigate assigns that reserved-address (IP) to dedicated pc?! regardless the pc is connected to whatever/any interfaces. Thanks!
    ede_pfau
    SuperUser
    ede_pfau
    SuperUser
    February 16, 2011
    The Fortigate will assign the reserved address only when the PC is connected to the interface on which the DHCP server is running which offers the range of IPs such that the reserved address is included.(wow, no intention) Say, you have 4 interfaces with DHCP servers on them with ranges 192.168.1.10-20 for interface 1, 192.168.2.10-20 for interface 2, etc. Your PC has the reserved address 192.168.2.11 - so it' s within the range of DHCP server on interface 2. The PC will be assigned this address only when connected to interface 2. Initially after " link up" signal of its interface the PC will ask for a renewal of the last address it was assigned. The DHCP server will offer an address from within its range, be it the old address or any available. Only on interface 2 the DHCP server will recognize the MAC address and offer the reserved address. And only this one.
    A
    Anonymous_User
    Contributor
    February 18, 2011
    It works :). Confirmed! Thanks ede_pfau!
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