This seemed like overkill to me, we already wont come close to filling
the single /64 but this might be my IPv4 mindset confusing me.
Stop counting hosts, that's IPv4 thinking. Subnets come in one size fits all, enormous. A /64 can address every IP device ever made with plenty room to spare.
Yet the address space is even bigger such that a single site ...
First: get that /48. For security and manageability not putting everything in a single broadcast domain (VLAN) is good practice.
Second: for servers just configure the addresses statically. You can use SLAAC, DHCPv6 and static addresses on the same network if you want.
It's not very common to put IPv6 addresses of workstations in DNS, but there are use ...
Alternatively I have the option to ask the ISP for a /48, should I do
that and advertise a single /64 for local clients to get connectivity
and different /64 for static servers?
Absolutely ask your ISP for a /48. You cannot subnet a /64 without breaking all kinds of things (including SLAAC).
Your idea of putting servers and local clients on a different ...
You're mixing a few things together that aren't really directly related.
If all of your domain joined clients are in the 10.190.8.0/21 network then just add that to ADS&S. If at some point you subnet the 10.190.8.0/21 network into /24 subnets and you deploy Domain Controllers in those subnets then you can reconfigure ADS&S accordingly. That being ...
I feel that the centralized network management is a huge plus, but there are people here who are dead set against it.
I think a lot of people that want/need central management have moved towards the configuration management (Ansible/Chef/Puppet/DSC/etc) way of doing things. So an individual computer may be configured with a static address. But that static ...
You seem to be using ISC dhcpd. From its dhcpd.conf(5) man page:
The next-server statement is used to specify the host address of the server from which the initial boot file (specified in the filename statement) is to be loaded. Server-name should be a numeric IP address or a domain name.
Note that the server name indicated by the ...
I tried the registry fix and it worked for me.
reg add "HKLM\SYSTEM\CurrentControlSet\Services\Dhcp" /v RequiredPrivileges /d "SeChangeNotifyPrivilege"\0"SeCreateGlobalPrivilege"\0"SeImpersonatePrivilege"\0 /t REG_MULTI_SZ /f
Is defined on RFC 3927 section 1.9:
If a host finds that an interface that was previously configured with an IPv4 Link-Local address now has an operable routable address available, the host MUST use the routable address when initiating new communications, and MUST cease dvertising the availability of the IPv4 Link-Local address through whatever mechanisms ...
What I always use is this
Literally it is the first answer
Or if you were a bash type like myself.
In a file say checkipaddress.sh, easily made with
wget -q -O - checkip.dyndns.org | sed -e 's/.*Current IP Address: //' -e 's/<.*$//'
I suggest starting two terminals, one for monitoring and another for sending a request. Terminal1 will show responses from all existing DHCP servers including MAC address. This example was run on Ubuntu:
Terminal1 (for monitoring):
sudo tcpdump -nelt udp port 68 | grep -i "boot.*reply"
tcpdump: verbose output suppressed, use -v or -vv for full protocol ...
I have a home modem/router/gateway. To make it less findable with
hard-coded bad-actor scripts running inside my network, I wanted to
put the modem/gateway IP address in the middle of the DHCP pool of
What exactly is a "hard-coded bad-actor script"?
If a rogue entity has access to your network, putting the router on an ip address other than ...
The DHCP server is on one subnet. You have DHCP clients on other subnets. In order for the DHCP traffic from these other subnets to reach the DHCP server you need a DHCP relay agent running on your router that will forward the DHCP traffic from those other subnets to your DHCP server.
Your DHCP relay agent is currently configured to forward DHCP traffic to ...
RFC 2132 (DHCP Options and BOOTP Vendor Extensions), section 3.8 says:
The domain name server option specifies a list of Domain Name System
[...] name servers available to the client. Servers
SHOULD be listed in order of preference.
"Should", not "Must", so, it depends on the client...
For example, Windows tries the first one, and falls back ...
If you're saying you've installed a VM host machine, and now you're running VM guests on it, you should install all your services on the guests.
So if you've installed AD Domain Services on the VM host, remove it and install it on one of the guests. AD and DNS must co-exist. You may have DHCP on there as well, although this is really only recommended in a ...
My build agent VM is Ubuntu 20.04 LTS, it did not have DHCP
pre-configured when I made a snapshot.
It should have.
If the VM had a static IP address when you took a snapshot of it, all clones created from that snapshot will try to use the same network config when they boot. This should not work at all, even if you wait when deploying them.
What I think is ...
I think I've come up with a reasonable solution for this.
Make sure the laptops have "Register this connection's addresses in DNS" enabled on their VPN connections.
Set a DHCP User Class on all of their network adaptors:
ipconfig /setclassid * "MyClass"
Create a DHCP policy in the relevant scope which only applies to DHCP clients who have the ...
Unfortunately you can't realize such scenario on GCP at the moment. You can use described ways to manage internal IPs by following documentation like Using a static internal IP address for a secondary network interface.
As a possible workaround you can file feature request on Google Issue Tracker under this component.
The lease is reserved for the entire 2 hour period. None of the newly connected devices can get that reservation until it is released after 2 hours. This is why in networks with a lot of "churn" using a 2 hour lease is a really good idea, instead of the default 24 hour lease.
It is a kind of zero-configuration networking, probably done by a small DHCP/DNS/TFTP server called dnsmasq. The PTR record allows you to see the hostname of other machines connecting to your computer, which might be meaningful on a small network, where people know each other.
As for scanning the network, other technologies announce on broadcast or ...
As mentioned in the comments.
It sounds like you need to bridge your VM network with the local physical ethernet device. Details about bridged networks can be found in the libvirt docs here
You can configure the guest to use the bridged interface with:
It depends on the dhcp server implementation. If there is no communication between the servers then the address pools should not overlap. If there is a communication mechanism, such as ISC's dhcp server, then the address pools can overlap.
To assign a specific address to a host, this address must be in the subnet but not in the range.
A fixed address is not assigned by the pool mechanism and therefore does not benefit from the options of this pool.
And the routers and subnet-mask options are relative to the pool and not to the subnet.
The easiest way here is to assign the address 226 to the ...
Is the interface (enp2s0) up at all ?
It needs to have an ipv4 address added and then started (up)
It shouldn't matter if any clients is connected to the hub/switch.
Network Manager ?
I hate that thing with a passion, but either way: if the iface isn't up with a correct address dhcpd wont start, so you need to figure out how to with nmcli create a ...
I eventually figured this out. I've put together a complete write-up at https://blog.oddbit.com/post/2019-12-19-ovn-and-dhcp/ that walks through the whole process.
I think the key problem in my earlier test was that in order for the OVN DHCP service to respond you must set some mandatory options in the dhcp_options entry. These aren't documented anywhere, ...
$ sudo nmap --script broadcast-dhcp-discover
uses the script broadcast-dhcp-discover found here:
you should replace:
result_table["IP Offered"] = r.yiaddr_str
result_table["IP Offered"] = r.yiaddr_str
result_table["IP TFTP Server"] = r.siaddr_str
Alternatively you could also use
You can remove the failover relationship via PowerShell with the following command.
Remove-DhcpServerv4Failover -ComputerName <ServerName> -Name <DHCPFailoverRelationshipName> -Force
Once you run the command on both servers, you can re-create the failover relationship.
Why aren't more people moving to DHCP for their server environment? Is it because that's the way it has always been done, and people don't like change?
Obviously we can't know why people don't move. I'll reply here because I had this "conflict" many times with many customers in my professional career.
I'm one from "DHCP camp". Where the customer has not ...