3
votes
dhcpd server invalid MAC detection
It depends on what you use to parse it, one can argue that it is completely valid to leave out prefix zeroes, and that is what we do most of the time because there is no definition of how many digits ...
3
votes
Unable to add forward map ...: SERVFAIL
it was indeed the jnl files. I had selinux issues earlier and in the process of resolving them it evidently left the empty files. Because of all the queries being logged, and the way I was filtering ...
2
votes
How can I assign an IP by UID in DHCPd
It is possible by using DUID-UUID.
On the server side it is required to identify the host by option dhcp-client-identifier like below:
host example {
option dhcp-client-identifier FF:II:II:II:II:00:...
2
votes
Accepted
CentOS 7 DHCP server fails to start (won't enable on specified port)
Your second interface (enp2s0) has no IP address. Set him up with address from defined network - ip addr add 192.168.100.1/24 dev enp2s0 and then run dhcp service again. IP address of that interface ...
2
votes
DHCP Client starts sending DHCP Discover messages upon receiving a NAK from another DHCP server
No. The screen shot you have provided is not a DHCPRequest renewal. Renewals are unicast to the DHCP server IP address. The screenshot shows a broadcast. Any DHCP server may respond to a broadcast ...
2
votes
Accepted
Exclude subnets from distribution?
Simple - don't add a range.
# servers
subnet 192.168.91.0 netmask 255.255.255.0 {
option routers 192.168.91.1;
}
And then later in your config, you can give out specific IPs in that subnet to ...
2
votes
Accepted
Edgerouter DNSmasq send updates to BIND
With a suggestion from @Tom I figured out a way to do this without using a BIND server.
The solution is to configure each ERX as the authoritative DNS server for its local subnet and create server ...
2
votes
Accepted
Multiple IPv6 routers on the same network
IPv4
The reason IPv4 behaves the way you have observed is that it wasn't originally intended to support more than one IP address on an interface. Hence the DHCP client will just wait for the first ...
2
votes
isc-dhcp-server: Using option dhcp-client-identifier in host declaration to identify a client
I had a similar issue with ISC DHCP 4.4.1, which I got working by prepending the id with a 0xff, i.e.:
host TestHost {
option dhcp-client-identifier ff:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:...
1
vote
Accepted
DHCP failover with PXE
I found an answer after much experimenting: It turns out that the order of the access-control statements within a pool matters.
Here's a repeat of the class definitions in my original post:
class &...
1
vote
dhcpd server invalid MAC detection
This is not an answer, but I just want to share this configuration. Where the DHCP server sets bootfile-name (option 67) to contain the mac-address of the client. But the mac is changed to end with 00 ...
1
vote
isc-dhcp-server: Using option dhcp-client-identifier in host declaration to identify a client
I've been facing this as well, and from what I've gathered the option is not officially supported in ISC DHCP 4.1 through 4.4. I've been playing with this as well as I have a trunk from my switch to ...
1
vote
dhcpd unexpectedly destributes a useless route for another subnet as a default gateway
I don't have enough reputation points to ask a couple of questions via comment. It would help to see your entire dhcpd.conf file and your network interfaces config as well as what distribution you ...
1
vote
How can I configure DHCP server to issue the same fixed-address by matching with the client identifier in the discover message
I think you have the syntax wrong.
Here is how I do it (based on a readable client id)
host aaa {
option dhcp-client-identifier = "XYZ-aaa";
fixed-address 123.123.123.123;
}
The "aaa" and "...
1
vote
Option 81 in DHCP
Two locations:
Configure the Primary DNS Suffix for a Client Computer.
Configure a Connection-Specific DNS Name
1
vote
CentOS 7 DHCP server fails to start (won't enable on specified port)
Configure enp2s0 interface with static ip address 192.168.100.1 in /etc/sysconfig/network-scripts/ifcfg-enp2s0 .
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/...
1
vote
Accepted
How can I clear the DHCP GUI in OSX Server? Ghost clients in the building
The ghosts have been captured.
The real lesson here
...is to always fully research, overview, and document all new hardware in your networks.
Make time to proactively volunteer to set ...
1
vote
ISC dhcpd dynamic bootfile-name. Is this possible?
110022334455 becomes 11022334455 in the ASCII output
see also: https://kb.isc.org/article/AA-01039/0/Formatting-MAC-addresses-in-dhcpd-or-why-does-binary-to-ascii-strip-leading-zeroes.html
1
vote
Accepted
DHCPD clean leases on client disconnect
If I correctly understood, to make a static lease you have something like this in your config:
host static-1 {
hardware ethernet 00:01:02:03:04:05;
fixed-address 192.168.1.40;
}
This will ...
1
vote
DHCPDISCOVER/DHCPOFFER, but no DHCPACK
In my case, the client was able to broadcast the DHCPDISCOVER and the server was able to reply with the DHCPOFFER, but the offer included a gateway IP for a router that didn't exist, so when the ...
1
vote
DHCPDISCOVER/DHCPOFFER, but no DHCPACK
In my case, my AP Controller has DHCP Protection enabled. It makes sure no AP forwards any DHCP replies that is not initiated from the specified IP/MAC.
Took me half a day to find this feature and ...
Only top scored, non community-wiki answers of a minimum length are eligible
Related Tags
dhcpd × 82dhcp × 30
isc-dhcp × 26
dhcp-server × 22
bind × 11
linux × 10
centos × 7
dhcp-option × 6
domain-name-system × 5
ddns × 5
pxe-boot × 4
ubuntu × 3
ip × 3
ipv6 × 3
wifi × 3
tftp × 3
networking × 2
debian × 2
iptables × 2
firewall × 2
centos7 × 2
cisco × 2
hostname × 2
static-ip × 2
cobbler × 2