Support Forum
The Forums are a place to find answers on a range of Fortinet products from peers and product experts.
waveruh
New Contributor

dhcp reserved-address doesn' t work

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
7 REPLIES 7
ede_pfau
SuperUser
SuperUser

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.
Ede Kernel panic: Aiee, killing interrupt handler!
Ede Kernel panic: Aiee, killing interrupt handler!
waveruh

Thanks. It' s work :)
jtfinley

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
rwpatterson
Valued Contributor III

ORIGINAL: jtfinley You wouldn' t reserve a hotel room and expect to stay at a different hotel?
LMAO! Now that' s funny!

Bob - self proclaimed posting junkie!
See my Fortigate related scripts at: http://fortigate.camerabob.com

Bob - self proclaimed posting junkie!See my Fortigate related scripts at: http://fortigate.camerabob.com
Not applicable

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
SuperUser

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.
Ede Kernel panic: Aiee, killing interrupt handler!
Ede Kernel panic: Aiee, killing interrupt handler!
Not applicable

It works :). Confirmed! Thanks ede_pfau!
Announcements

Select Forum Responses to become Knowledge Articles!

Select the “Nominate to Knowledge Base” button to recommend a forum post to become a knowledge article.

Labels
Top Kudoed Authors