DHCP / Cisco IPhelper - Problem to get valid IP-Adresses

You are missing a critical element what is the configuration of the
subnet do you multinet (aka secondary)?
The 'ip helper-address' in the cisco's only cause the router to edit the
giaddr field of the DHCP packet, tear off the IP broadcast headers and
then resend them as unicast to the 'helper-address' as a destination.

Regards,
Tim Peiffer

The 192.168.4.2 is the address of the iphelper.
Are we doing something wrong on the dhcp-Severs (misconfiguration) or is this a
indicate of a IP-Helper / Cisco misconfiguration ?
What configuration infos about the Ciscos are further required, to adress the problem ?
I will try to get these, please let me know
>
Thank you,
>
Christian



--
Tim Peiffer
Network Support Engineer
of Information Technology
University of Minnesota/NorthernLights GigaPP

Christian Binder wrote:
>Thanks for your quick reply and sorry for my mistake. Here are my
>subnet-declaration parts:
>The Hosts are actually insdide the subnet declaration. If we move a
>client, we move his entry in the new one.
>
># Department001_192.168.3.0/24
>subnet 192.168.3.0 netmask 255.255.255.0 {
server-name "depot.company.de";
option subnet-mask 255.255.255.0;
option domain-name "company.de";
option domain-name-servers 192.168.1.64 , 192.168.1.4, 192.168.1.5;
option routers 192.168.3.1;
option broadcast-address 192.168.3.255;
option ntp-servers ntp01.company.de;
pool {
failover peer "dhcp-failover";
max-lease-time 1800;
range 192.168.3.10 192.168.3.15;
deny dynamic bootp clients;
}
#
host marpa352MF

}
>


Take some advice - move the host declarations out of the subnet
declarations as this setup WILL cause you headaches sooner or later.

Host statements are global in scope, as in they WILL match a host
even if the host is in a different subnet. However, what can happen
is that a client may match the host, get an IP address from the
dynamic range for the network where it is located, but inherit
options from the subnet where the host statement is declared.
I think you can see the scope for confusion when a host gets (say)
and address in the 192.168.3.0/24 subnet, but gets 192.168.4.1 as
it's router ! Yes, we have seen that problem on this list.

Hi all,

a few weeks ago I posted a message about a problem that I encountered.
I had a two server dhcp redundant/failover setup and I deleted the
dhcp.leases(~) files as I did not have enough room to save them. ( I
know a very stupid thing to do. no excuses).

I have been running on a single (with none failover) dhcp server and
want to return to a two server configuration. I am not doing DDNS, so I
don't have to worry about that now. The problem is that when I restart
both servers they STP offering IP addresses, and I see a lot of
recovering messages on the logs.

What do I have to do? reset a file, or delete files or anything to start
from scratch. When I first started with this configuration I had no
problem. Any Help is greatly appreciated as I don't feel good running
on a single server.

Thanks in advance.

Luis


Luis Fernando Lacayo
Chicago Public Schools
Senior Unix Administrator
ITS/ UNIX Infrastructure
: 773-553-3835
Cell: 773-203-4493

Luis Fernando Lacayo wrote:

>a few weeks ago I posted a message about a problem that I
>encountered. I had a two server dhcp redundant/failover setup and I
>deleted the dhcp.leases(~) files as I did not have enough room to
>save them. ( I know a very stupid thing to do. no excuses).
>
>I have been running on a single (with none failover) dhcp server and
>want to return to a two server configuration. I am not doing DDNS,
>so I don't have to worry about that now. The problem is that when I
>restart both servers they STP offering IP addresses, and I see a
>lot of recovering messages on the logs.

First thing to do is NT to hijack threads - your query is not
related to "DHCP / Cisco IPhelper - Problem to get valid IP-Adresses"
! It would be best if you went back and found a message in your own
earlier thread and replied to that - that way your 'sort of related'
query would get threaded with it.

simply start a new thread - it's not hard.


In reply to your query - first step in any situation like this is to
look in the logs, they are often informative of the problem.

So what do your logs say 1) when you start the servers, and 2) when a
client is attempting to get an address.

»¿

a few weeks ago I posted a message about a problem that I
encountered. I had a two server dhcp redundant/failover setup and I
deleted the dhcp.leases(~) files as I did not have enough room to
save them. ( I know a very stupid thing to do. no excuses).

I have been running on a single (with none failover) dhcp server and
want to return to a two server configuration. I am not doing DDNS,
so I don't have to worry about that now. The problem is that when I
restart both servers they STP offering IP addresses, and I see a
lot of recovering messages on the logs.


When I start the servers, the logs show the following:Jul 28 07:56:36
D4FWWC1 dhcpd: Sending on
Jul 28 07:56:36 D4FWWC1 dhcpd: Listening on

Jul 28 07:56:36 D4FWWC1 dhcpd: Sending on Socket/fallback/fallback-net
Jul 28 07:56:36 D4FWWC1 dhcpd: Sending on

Jul 28 07:56:36 D4FWWC1 dhcpd: failover peer co-wan03: I move from
recover to startup
Jul 28 07:56:36 D4FWWC1 dhcpd: Sending on Socket/fallback/fallback-net
Jul 28 07:56:37 D4FWWC1 dhcpd: failover peer co-wan03: I move from
recover to startup
Jul 28 07:56:37 D4FWWC1 dhcpd: dhcpd startup succeeded

skip a few lines and I see the same message for most of the subnets on
the dhcpd.conf file.


DHCPREQUEST for 10.129.77.204 from 00:12:3f:08:0d:e3 via 10.129.76.3: not responding (recovering).

Thanks,

Luis




--
Luis Fernando Lacayo
Chicago Public Schools
Senior Unix Administrator
ITS/ UNIX Infrastructure
: 773-553-3835
Cell: 773-203-4493