CNR DHCP relay problem 05991

Unanswered Question
Mar 17th, 2010

Hi! Using CNR Release as DHCP server trying to get IP address through DHCP relay agent. CNR shows the following log:

FileName Match Line Number Log Number
name_dhcp_1_log 4103 1
03/17/2010 15:32:02 name/dhcp/1 Info Failover 0 05991 Received
DHCPDISCOVER packet from client Host: 'RoverbookU100' CID:
01:00:21:85:51:b9:33 but failover load balancing in state of normal did
not allow network ''to respond to this client. Dropping

What could be the problem of this?

I have this problem too.
0 votes
  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
lakradha Thu, 03/18/2010 - 03:19

I have few queries from your mail.

#1  Since failover load balancing is enabled.  Have you noticed the following issuse in both the DHCP servers (main and backup) ?

      Have you verified the log in the failover partner ?

#2   Do you have relevant scopes configured in the DHCP server for the incoming DHCP request packet ?

DHCP log files from both the failover partners will help us to scrutinize the issue ?

If you have cisco account, then please post your queries to [email protected] mailing alias



[email protected]

vinbalak Thu, 03/18/2010 - 03:48

Hi there,

This message is perfectly normal which means that you have configured failover Load Balancing and the request is not being processed by this server as it is expecting the failover partner to process the request.

Now, you should find this processed in the failover partner (as that is how load balancing works). If you dont find the corresponding message on the partner, this indicates a misconfigured relay-agent. (i.e. one that wasn't relaying the DHCP traffic to both failover partners) and they could be locally connected clients which means the clients are on the same interface to which the servers are connected which in turn would imply that the DHCPDISCOVERs sent were not broadcast, but unicast to the server which violates the DHCP protocol. Remember, the DHCPDISCOVERs are always broadcast.!!



This Discussion