Re: dhcpd assign duplicated IP address
Bill Moran 写道: In response to Zhang Weiwu <[EMAIL PROTECTED]>: P.S. In recent days we some times got another network problem and I'm not sure if it's related to this DHCP server behavior. It happens on both Linux and Windows hosts that a host suddenly is no longer accessible (Ping no response). Check 'arp -a' on other hosts shows the host being accessed have wrong Mac Address. e.g. yesterday 218.193.55.195 suddenly become in-accessible, this host is Linux and we got this behavior on a nearby host: sappho # arping 218.193.55.195 Unicast reply from 218.193.55.195 [00:0F:EA:4B:82:58] 0.638ms Unicast reply from 218.193.55.195 [00:0F:EA:4B:82:58] 0.637ms Sent 113 probes (1 broadcast(s)) Received 113 response(s) sappho # arp -a 218.193.55.195 ? (218.193.55.195) at 00:02:2A:C1:53:87 [ether] on eth0 arping reply is different from arp cache. This host become accessible the next day. Strange. Are these two problems related? You have something seriously wrong somewhere. They may be related but there's not enough information here to be sure. Consider installing arpwatch on one or more systems and see if the reports it sends narrow down the problem. I have followed Jeffrey's suggestion and reconfigured dhcpd.conf to make sure no host with specified IP address is within dynamic assigned IP range. I was mislead by my previous experience with Microsoft DHCP server configuration where a host with fixed IP address should be within the range. After updated dhcpd.conf I haven't see an IP conflict yet, I'll watch a few days. For the ARP issue, thanks for suggesting arpwatch. I'd like to take a deeper look into how ARP works later. Thanks! ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: dhcpd assign duplicated IP address
In response to Zhang Weiwu <[EMAIL PROTECTED]>: > > P.S. In recent days we some times got another network problem and I'm > not sure if it's related to this DHCP server behavior. It happens on > both Linux and Windows hosts that a host suddenly is no longer > accessible (Ping no response). Check 'arp -a' on other hosts shows the > host being accessed have wrong Mac Address. e.g. yesterday > 218.193.55.195 suddenly become in-accessible, this host is Linux and we > got this behavior on a nearby host: > > sappho # arping 218.193.55.195 > Unicast reply from 218.193.55.195 [00:0F:EA:4B:82:58] 0.638ms > Unicast reply from 218.193.55.195 [00:0F:EA:4B:82:58] 0.637ms > Sent 113 probes (1 broadcast(s)) > Received 113 response(s) > sappho # arp -a 218.193.55.195 > ? (218.193.55.195) at 00:02:2A:C1:53:87 [ether] on eth0 > > arping reply is different from arp cache. This host become accessible > the next day. Strange. Are these two problems related? You have something seriously wrong somewhere. They may be related but there's not enough information here to be sure. Consider installing arpwatch on one or more systems and see if the reports it sends narrow down the problem. -- Bill Moran http://www.potentialtech.com ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: dhcpd assign duplicated IP address
On Apr 18, 2007, at 9:24 PM, Zhang Weiwu wrote:
I am not sure if I understood DHCP correctly. I have this
configuration
in my /usr/local/etc/dhcpd.conf (Using FreeBSD 6.1):
subnet 218.193.55.192 netmask 255.255.255.192 {
range 218.193.55.194 218.193.55.254;
option routers 218.193.55.193;
}
[snip]
host sappho.realss.com {
hardware ethernet 80:00:20:B0:99:31;
fixed-address 218.193.55.196;
option routers 218.193.55.193;
}
And I think this means the DHCP server should not assign IP address
218.193.55.196 to any hosts that do not have MAC address of
"80:00:20:B0:99:31".
No, it doesn't mean that. You have configured dhcpd to have two ways
of assigning the address 218.193.55.196. One is through the dynamic
mechanism and the other is through the fixed address.
You should set your fixed address to be outside of your dynamic pool
range.
Cheers,
-j
--
Jeffrey Goldberghttp://www.goldmark.org/jeff/
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