DHCP options#

General information#

The Dynamic Host Configuration Protocol (DHCP) is a standard for passing configuration information to hosts on a TCP/IP network.

In addition to the service parameters, a cloud DHCP server always communicates the following options:

  • Router (option 3) – the first subnet address used;

  • Address Time (option 51) – the lease duration for the address (1 hour);

  • Hostname (option 12) – in the following format: ip-<IP address separated by hyphens>;

  • Domain Name (option 15) – <vpc-id>.internal is used by default.

Additionally, you can specify values for the following options:

  • Domain Server (option 6) – the DNS server address;

  • NTP Servers (option 42) – the NTP server addresses;

  • Domain Name (option 15) – the DNS domain name;

  • NETBIOS Name Srv (option 44) – the NETBIOS server name;

  • NETBIOS Node Type (option 46) – the NETBIOS node type.

When you create a VPC in K2 Cloud, an empty DHCP parameter set is automatically created. You can create your own DHCP parameters for your VPC.

Create/delete DHCP parameters#

To create a set of custom DHCP parameters, go to Virtual machines Networking DHCP options and click Create.

You may specify just those parameters that your DHCP parameter set requires. An empty DHCP parameter set is created by default. You may assign your own domain name to your instances and use up to four of your own DNS servers.

Here is the list of supported DHCP parameters:

  • Domain name

  • DNS servers – List of IP addresses of domain name servers or AmazonProvidedDNS. We recommend using only one of the two parameters.

  • NTP servers – the IP addresses of Network Time Protocol (NTP) servers. You can specify up to four IP addresses.

  • WINS servers – the IP addresses of WINS servers. You can specify up to four IP addresses.

  • NetBIOS node type – the NetBIOS node type (1, 2, 4, or 8):

    • 1 – Broadcast (no WINS)

    • 2 – Peer-to-peer (WINS)

    • 3 – Mixed mode (broadcast then WINS)

    • 8 – Hybrid (WINS then broadcast)

You can also assign the Name tag and additional tags to a DHCP parameter set.

Once a DHCP parameter set is created, it cannot be changed. To have the VPC use a different DHCP parameter set, create a new set and assign it to your VPC.

To delete unnecessary DHCP parameter sets, click Delete. Make sure that VPCs are now assigned another parameter set instead of the one they used.

Assign/reset DHCP parameters#

To assign the created DHCP parameter set to a VPC, go to Virtual machines Networking DHCP options and click Assign.

After you assign a new parameter set to a VPC, all existing instances and any new instances you start in the VPC will use the new parameters. The applied DHCP options will be given back/returned by the DHCP server at the next access to it.

To reset the created DHCP parameter set and assign the default parameters, click Reset.

Assigning tags#

To add, modify or delete tags for a DHCP parameter set:

  1. Go to the Access and security section DHCP options.

  2. In the resource table, find the DHCP parameter set for which tags should be edited and click on the ID of the DHCP parameter set to go to its page.

  3. Open the Tags tab.

  4. To add a tag, click Add tag and specify the Key and Value fields.

    To modify a tag, edit the required fields (Value and/or Key) of the respective tag.

    To delete a tag, click the icon next to the tag you no longer need.

    Note

    If no tags have been set earlier, you can add the Name tag by clicking Add Name tag and specifying its value.

    Note

    You can also modify the Name tag in the Information tab by editing the corresponding field.

  5. Click Apply to save the changes.

Information about DHCP parameters#

General information about DHCP options can be viewed in the resource table in Virtual machines Networking DHCP options. To open a page with a particular set of DHCP options, click its ID in the resource table in the DHCP options subsection.

The Information tab displays the main parameters of the DHCP options set:

  • Name tag;

  • domain name;

  • list of DNS servers;

  • list of NTP servers;

  • list of WINS servers;

  • NetBIOS node type;

  • number of VPCs to which the DHCP options set is assigned.

Here you can modify the Name tag and delete the DHCP options set by clicking Delete.

The VPC tab displays a table with details of the VPCs to which the selected DHCP options set is assigned:

  • ID;

  • name;

  • state;

  • CIDR.

Here you can assign or reset DHCP options.

The Tags tab displays all tags assigned to the resource. You can add new, modify existing, and delete no-longer-needed tags.