[lug] dhcpcd lease issue

D. Stimits stimits at attbi.com
Tue Aug 20 17:04:03 MDT 2002


Chuck Wiechman wrote:
> That is my question the same box (for whatever reason) decides to give up
> its ip address and get a new one. I did not reboot the box, for whatever
> reason it is just does this by itself. There aren't any other machines on
> this lan to cause a duplicate IP, and there are no sub-interfaces on the
> laptop either.
> 
> For whatever reason it has managed to keep its ip of .53 for the last few 
> hours. I tried running the /sbin/fuser -v -u -n tcp "68" -n udp "68" 
> command and it gave no output.

This means that the standard port for DHCP client has nothing listening. 
The machine without a port 68 listener is probably a machine that does 
not exist, so far as the DHCP server is concerned. With nothing 
listening, there is no possibility of the DHCP client 
succeeding...though the server will keep trying. Perhaps your interface 
was using the right IP due to prior setup, but the server does not 
believe it, so it retries...port 67 on the server could be seeing the 
request, then it will reply to port 68, and the lights are on but nobody 
is home.

Go to /etc/sysconfig/network-scripts/ (not where people usually tell me 
to go, smirk), and find the ifcfg-whatever that corresponds to your 
ethernet device. Looks like eth0, so ifcfg-eth0. What are the contents? 
It should be something similar to:
DEVICE=eth0
ONBOOT=yes
BOOTPROTO=dhcp

If that is not there, comment out the old entries (lead with '#'), and 
add that in. Then cd to /etc/rc.d/init.d/, and run "./network restart". 
See what happens, and monitor /var/log/messages in another window while 
you do it.

D. Stimits, stimits AT attbi.com

> 
> 
>>From the laptop:
> 
> eth0      Link encap:Ethernet  HWaddr 00:10:A4:E0:43:DF  
>           inet addr:10.1.1.53  Bcast:10.1.1.255  Mask:255.255.255.0
>           UP BROADCAST NOTRAILERS RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:60 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:48 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:100 
>           RX bytes:8422 (8.2 Kb)  TX bytes:10594 (10.3 Kb)
>           Interrupt:11 Base address:0x4000 
> 
> 
> 
> 
> On Tue, 20 Aug 2002, John Hernandez wrote:
> 
> 
>>|>>Aug 20 11:57:00 firewall dhcpd: already acking lease 10.1.1.51
>>|>>Aug 20 11:57:00 firewall dhcpd: Abandoning IP address 10.1.1.51:
>>pinged before offer
>>
>>It looks like the DHCP server is getting flooded with DISCOVER messages
>>from that same MAC address.  Are there subinterfaces on the client that
>>are also requesting DHCP addresses?
>>
>>Could there be boxes on the network that have statically assigned
>>(stolen) addresses out of the DHCP pool?
>>
>>Chuck Wiechman wrote:
>>| The dhcp server (yes the output below came from the serer) is on the same
>>| net with IP address 10.1.1.1, there is no firewalling on that interface.
>>|
>>|
>>| On Tue, 20 Aug 2002, D. Stimits wrote:
>>|
>>|
>>|>Chuck Wiechman wrote:
>>|>
>>|>>I recently upgraded my laptop from redhat 7.1 to 7.3. After the upgrade,
>>|>>the laptop is having issues keeping the same IP address. For some reason
>>|>>it keeps requesting a new IP, and giving up its old one. I am pretty
>>sure
>>|>>there is nothing wrong with the dhcp server (redhat 7.2 it has been
>>|>>running for months just fine), and it exhibits the same behavior at
>>work
>>|>>with a debian dhcp server.
>>|>>
>>|>>The only difference that I can see is that 7.3 uses dhcpcd instead
>>of the
>>|>>pump client. I don't see any patches for dhcp on redhats page. Is
>>this a
>>|>>know bug? Should I go back to pump?
>>|>
>>|>I just installed dhcp client on my machine for cable modem, RH 7.3. I
>>|>could not get pump to work, but dhcpc worked without any effort. The one
>>|>thing that initially hurt was having the firewall block
>>|>non-Internet-routable addresses...it turns out that AT&T uses one of
>>|>those to talk via dhcp to users. The output below is from the dhcp
>>|>server (I hope it isn't running on the laptop...it could be trying to
>>|>serve itself), I wonder if "abandoned" can be caused by a blocked port
>>|>or address? Did your upgrade change anything at all to do with
>>firewalling?
>>|>
>>|>D. Stimits, stimits AT attbi.com
>>|>
>>|>
>>|>>
>>|>>dhcpd.leases
>>|>>---------------------------------------------------
>>|>>lease 10.1.1.51 {
>>|>>        starts 2 2002/08/20 17:57:00;
>>|>>        ends 2 2002/08/20 17:57:00;
>>|>>        abandoned;
>>|>>}
>>|>>lease 10.1.1.50 {
>>|>>        starts 2 2002/08/20 01:20:46;
>>|>>        ends 2 2002/08/20 01:20:48;
>>|>>        hardware ethernet 00:10:a4:e0:43:df;
>>|>>        uid 01:00:01:02:79:2d:87;
>>|>>}
>>|>>lease 10.1.1.64 {
>>|>>        starts 2 2002/08/20 01:19:42;
>>|>>        ends 2 2002/08/20 01:19:42;
>>|>>        abandoned;
>>|>>}
>>|>>lease 10.1.1.53 {
>>|>>        starts 2 2002/08/20 17:57:10;
>>|>>        ends 2 2002/08/20 21:57:10;
>>|>>        hardware ethernet 00:10:a4:e0:43:df;
>>|>>        uid 01:00:01:02:79:2d:87;
>>|>>}
>>|>>lease 10.1.1.53 {
>>|>>        starts 2 2002/08/20 17:57:11;
>>|>>        ends 2 2002/08/20 21:57:11;
>>|>>        hardware ethernet 00:10:a4:e0:43:df;
>>|>>        uid 01:00:01:02:79:2d:87;
>>|>>}
>>|>>
>>|>>
>>|>>
>>|>>Aug 20 09:56:59 firewall dhcpd: DHCPDISCOVER from 00:10:a4:e0:43:df
>>via eth0
>>|>>Aug 20 09:57:00 firewall dhcpd: DHCPOFFER on 10.1.1.51 to
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 09:57:00 firewall dhcpd: DHCPDISCOVER from 00:10:a4:e0:43:df
>>via eth0
>>|>>Aug 20 09:57:00 firewall dhcpd: DHCPOFFER on 10.1.1.51 to
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 09:57:00 firewall dhcpd: DHCPREQUEST for 10.1.1.51 from
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 09:57:00 firewall dhcpd: DHCPACK on 10.1.1.51 to
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 11:57:00 firewall dhcpd: DHCPDISCOVER from 00:10:a4:e0:43:df
>>via eth0
>>|>>Aug 20 11:57:00 firewall dhcpd: DHCPDISCOVER from 00:10:a4:e0:43:df
>>via eth0
>>|>>Aug 20 11:57:00 firewall dhcpd: already acking lease 10.1.1.51
>>|>>Aug 20 11:57:00 firewall dhcpd: Abandoning IP address 10.1.1.51:
>>pinged before offer
>>|>>Aug 20 11:57:08 firewall dhcpd: DHCPDISCOVER from 00:10:a4:e0:43:df
>>via eth0
>>|>>Aug 20 11:57:09 firewall dhcpd: DHCPOFFER on 10.1.1.52 to
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 11:57:09 firewall dhcpd: DHCPDISCOVER from 00:10:a4:e0:43:df
>>via eth0
>>|>>Aug 20 11:57:10 firewall dhcpd: DHCPOFFER on 10.1.1.53 to
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 11:57:10 firewall dhcpd: DHCPREQUEST for 10.1.1.53 from
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 11:57:10 firewall dhcpd: DHCPACK on 10.1.1.53 to
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 11:57:11 firewall dhcpd: DHCPREQUEST for 10.1.1.53 from
>>00:10:a4:e0:43:df via eth0
>>|>>Aug 20 11:57:11 firewall dhcpd: DHCPACK on 10.1.1.53 to
>>00:10:a4:e0:43:df via eth0






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