Wireless Access

Hi,

After upgrading my 7220 from 6.5.1.7 to 6.5.1.10, I see an huge amount of continues DHCP messages being flood in the controller.

When doing a 'show log network all', I get the following output:

|dhcpdwrap| |dhcp| Received DHCP packet from Datpath, Flags 0x42, Opcode 0x5a, Vlan xxx, Ingress pc1, Egress vlan xxx, SMAC xx:xx:xx:xx:xx:xx

Does/did anyone experience the same?

Make sure you don't have a loop in your network.

Type "show cpuload current" to see if the CPU is high.

Hi Colin, thanks for your reply.

Just checked the cpu load, nothing wrong here:

user 0.5%, system 1.8%, idle 97.7%, iowait 5667

I've checked other DHCP stats but nothing unusaul from my point of view:

(xxx) #show ip dhcp data

DHCP disabled

(xxx) #show ip dhcp statistics

DHCPv4 disabled; DHCPv6 disabled

DHCP Pools
----------
Network Name  Type  Active  Configured leases  Active leases  Free leases  Expired leases  Abandoned leases
------------  ----  ------  -----------------  -------------  -----------  --------------  ----------------
 
Current leases          0
Total leases            10240
 
NOTE: To make a DHCPv6 pool active, ensure that the pool name is added in vlan interface

(xxx) #show ip dhcp binding   

(xxx) #show ip dhcp vlan   

DHCP User Table
---------------
VLAN  ADDR            MASK             OPtion-82
----  ----            ----             ---------
xxx   xxx.xxx.xxx.xxx  255.255.255.0    Disabled

Any other suggestions? As far as I've noticed this message wasn't there in the previous release. Could be either the message wasn't there or the message was there but no being reported in the logging.

That logging message has to do with DHCP traffic observed, not served up by the controller.  If the controller simply is on a wired VLAN where it can see DHCP traffic, you will see that message.  It is not cause for alarm.

Thanks for the reply Colin.

I'm aware the messages are only observed by the controller, it's just that I didn't notice them in the previous code and now there is a large portion to be found in the log which concerned me a little bit.

As long as it doesn't impact the controller to much, it is of good use knowing what is going on regarding DHCP behaviour.

Still investigating the root cause why several systems keep requesting for DHCP instead of once and using that.