LAN Routing
1753523 Members
11490 Online
108795 Solutions
New Discussion

Complete IP pool is marked as conflicting on DHCP request

 
SOLVED
Go to solution
graphite
Occasional Contributor

Complete IP pool is marked as conflicting on DHCP request

 I am setting up a DHCP server running on one of MSR3012 interfaces:

 

>display interface GigabitEthernet 0/1 brief 
...
Interface Link Protocol Primary IP Description 
GE0/1 UP UP 192.168.202.1 Workstations

>display dhcp server pool 
...
Network: 192.168.202.0 mask 255.255.255.0 
address range 192.168.202.100 to 192.168.202.200
expired 1 0 0 0
gateway-list 192.168.202.1

 

I don't see any problem here, but when an actual DHCP request comes in the router marks all of the IPs in the pool as conflicting:

*Sep 14 23:16:09:005 2018 Main router DHCPS/7/PACKET: 
From 0.0.0.0 port 68, interface GigabitEthernet0/1
Message type: REQUEST (1)
Hardware type: 1, Hardware address length: 6
Hops: 0, Transaction ID: 1891928330
Seconds: 0, Broadcast flag: 0
Client IP address: 0.0.0.0 Your IP address: 0.0.0.0
Server IP address: 0.0.0.0 Relay agent IP address: 0.0.0.0
Client hardware address: <stripped>
Server host name: not configured
Boot file name: not configured
DHCP message type: DHCPDISCOVER (1)
*Sep 14 23:16:09:005 2018 Main router DHCPS/7/EVENT: Receive a DHCPDISCOVER message from GigabitEthernet0/1.
*Sep 14 23:16:09:005 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.100.
*Sep 14 23:16:09:005 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.101.
*Sep 14 23:16:09:005 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.102.
*Sep 14 23:16:09:005 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.103.
*Sep 14 23:16:09:006 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.104.
*Sep 14 23:16:09:006 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.105.
*Sep 14 23:16:09:006 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.106.
...
*Sep 14 23:16:09:006 2018 Main router DHCPS/7/EVENT: Add a conflict IP 192.168.202.200.

After this DHCP server is not able to offer a lease to any clients. Any ideas why this could happen:?

5 REPLIES 5
graphite
Occasional Contributor

Re: Complete IP pool is marked as conflicting on DHCP request

Few more notes. I use the latest firmware, I can see all IPs as free in the pool before DHCP request arrives, the client is a single Ubuntu laptop connected directly to the router, it works fine with a static IP from the same subnet outside of the pool or with other DHCP servers. The problem is reproducible: if I reset IP conflicts all IPs become available and then are marked as conflicting simultaneously as soon as another DHCP request arrives.

akg7
HPE Pro

Re: Complete IP pool is marked as conflicting on DHCP request

Hi,

Could you please share the current configuration of the MSR Router, specially all DHCP configuration?

Thank You!

I am an HPE Employee

Note: While I am an HPE Employee, all of my comments (whether noted or not), are my own and are not any official representation of the companyAccept or Kudo
graphite
Occasional Contributor

Re: Complete IP pool is marked as conflicting on DHCP request

Thank you for looking into it! I will post all the configuration ASAP. In the meantime, is there any particular command that can display complete DHCP configuration or I need to output all of it separately (IP pools, interfraces, DHCP server status, etc)?

akg7
HPE Pro

Re: Complete IP pool is marked as conflicting on DHCP request

Hi,

Try this 

display current-configuration | include dhcp

or

display current-configuration begin dhcp

if it will not work then share full.

 

Thank You!

I am an HPE Employee

Note: While I am an HPE Employee, all of my comments (whether noted or not), are my own and are not any official representation of the companyAccept or Kudo
graphite
Occasional Contributor
Solution

Re: Complete IP pool is marked as conflicting on DHCP request

And thank you again!

I found out what the problem was: misconfigured static NAT had IP pool that was overlapping with DHCP pool. The problem manifested in a rather strange way, but apparently DHCP assigned IP was indeed conflicting with IPs that router was supposed to use for NAT.