dhcp server dropping external ip

schurt · 07-07-2004, 06:33 AM

after so many hours the dhcp server just drops the external ip and i am unable to ping outside of network. ive read up on the leases part of the dhcp configuration but not exactly sure if that is my problem or not, is there anything i need to check as to why the connection to the outside world is being dropped randomly?

here is my dhcpd.conf file

subnet 192.168.1.0 netmask 255.255.255.0 {
option routers 192.168.1.100;
option subnet-mask 255.255.255.0;

option domain-name "nc.rr.com";
option domain-name-servers 24.25.4.109;

option time-offset -18000;

host server1 {
option host-name "server1.servbox.com";
hardware ethernet 00:08:A1:73:E8:44;
fixed-address 192.168.1.100;
}

host flea {
option host-name "flea.servbox.com";
hardware ethernet 00:60:08:C7:84:69;
fixed-address 192.168.1.10;
}

}

thanks

ppuru · 07-07-2004, 06:50 AM

please post the output of

/sbin/ifconfig (or ipconfig /all)

from one of your client pcs.

This does not appear to be a dhcp related problem.

Can you give is more information about your network - how you hook up to the internet, whether the dhcp-server is your gateway to the internet?

Is ipforwardng enabled

cat /proc/sys/net/ipv4/ip_forward

has iptables been configured for MASQUERADE-ing internal connections?

schurt · 07-07-2004, 06:07 PM

this is basically what i run on the server to restart dhcp to pick up the outside ip again.

Code:

[root@rdu57-89-125 dhcp]# dhclient
Internet Software Consortium DHCP Client V3.0pl2
Copyright 1995-2001 Internet Software Consortium.
All rights reserved.
For info, please visit http://www.isc.org/products/DHCP

Listening on LPF/lo/
Sending on   LPF/lo/
Listening on LPF/eth1/00:08:a1:73:e8:44
Sending on   LPF/eth1/00:08:a1:73:e8:44
Listening on LPF/eth0/00:01:02:ea:c5:bb
Sending on   LPF/eth0/00:01:02:ea:c5:bb
Sending on   Socket/fallback
DHCPDISCOVER on lo to 255.255.255.255 port 67 interval 3
DHCPDISCOVER on eth1 to 255.255.255.255 port 67 interval 8
DHCPOFFER from 192.168.1.100
DHCPREQUEST on eth1 to 255.255.255.255 port 67
DHCPACK from 192.168.1.100
bound to 192.168.1.100 -- renewal in 20685 seconds.
[root@rdu57-89-125 dhcp]# ls -alt
total 12
-rw-r--r--    1 root     root          964 Jul  7 19:00 dhclient.leases
drwxr-xr-x    2 root     root         4096 Jul  7 19:00 .
drwxr-xr-x   18 root     root         4096 Jul  4 16:04 ..
[root@rdu57-89-125 dhcp]# ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:01:02:EA:C5:BB
          inet addr:66.57.89.125  Bcast:255.255.255.255  Mask:255.255.252.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3712552 errors:0 dropped:0 overruns:0 frame:0
          TX packets:306037 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:692057628 (659.9 Mb)  TX bytes:25607649 (24.4 Mb)
          Interrupt:11 Base address:0xac00

eth1      Link encap:Ethernet  HWaddr 00:08:A1:73:E8:44
          inet addr:192.168.1.100  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:356821 errors:0 dropped:0 overruns:0 frame:0
          TX packets:513708 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:30207433 (28.8 Mb)  TX bytes:499937236 (476.7 Mb)
          Interrupt:15 Base address:0x2000

lo        Link encap:Local Loopback
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:26863 errors:0 dropped:0 overruns:0 frame:0
          TX packets:26863 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:8886618 (8.4 Mb)  TX bytes:8886618 (8.4 Mb)

schurt · 07-07-2004, 07:37 PM

ps, using shorewall for MASQ, and yes ip_forward is enabled in /etc/sysctl.conf

schurt · 07-08-2004, 06:42 AM

im starting to see some errors in dhclient like

send_packet: operation not permitted

any clues?

schurt · 07-09-2004, 03:31 PM

anyone?

ppuru · 07-10-2004, 05:54 AM

Sorry for the delayed response ...

Quote:

im starting to see some errors in dhclient like

send_packet: operation not permitted

This could point to firewall configuration.

Are you unable to get to the Internet from any of your machines or a select few?
Your dhcpserver IP is in the IP pool of 192.168.1.1 - 192.168.1.254. This could be a problem area. Change the pool from say, 192.168.1.26 to 192.168.1.200. That will leave you with unallocated IPs for your servers.

schurt · 07-11-2004, 10:29 PM

ok ill try that, but yea it's from any workstation machine going through the server housing dhcp