--- title: "Configuring DHCP Options" description: "Exoscale VPC: Configure DHCP Options" url: https://community.exoscale.com/product/networking/vpc/how-to/configuring-dhcp-options/ product: "VPC" section: product last_updated: 2026-10-28 --- > For AI agents: the documentation index is at https://community.exoscale.com/llms.txt. Every page is available as markdown at `index.md` or with `Accept: text/markdown`. # Configuring DHCP Options With VPC, it's possible to configure the virtual DHCP server to pass some DHCP options. This can be useful to easily configure your instances from a single place. The following options are available: - [DHCP Option 6] DNS Servers. - [DHCP Option 42] NTP Servers. - [DHCP Option 119] Domain Search List. > [!WARNING] > These DHCP options apply globally to the entire instance, not just the VPC interface. > For example, depending on your instance configuration, all DNS queries may be > forwarded to the DNS server set in the VPC config. ## Set DHCP Options when creating a VPC You can create a VPC directly with DHCP options configured. ```console $ exo networking vpc create my-vpc --dns-server 8.8.8.8 --dns-server 1.1.1.1 --ntp-server 162.159.200.1 --ntp-server 216.239.35.0 --domain-search myorg.internal --domain-search exoscale.gva2.internal ✔ Creating VPC "my-vpc"... 0s ┼──────────────┼────────────────────────────────────────────────────────────┼ │ VPC │ │ ┼──────────────┼────────────────────────────────────────────────────────────┼ │ ID │ ebd4b6c9-3a10-4850-983f-2411b650fa1f │ │ Name │ my-vpc │ │ Description │ │ │ Default │ false │ │ Zone │ ch-gva-2 │ │ Created At │ 2026-10-27 15:32:22 +0000 UTC │ │ DHCP options │ │ │ │ DNS Servers 8.8.8.8, 1.1.1.1 │ │ │ NTP Servers 162.159.200.1, 216.239.35.0 │ │ │ Domain Search myorg.internal, exoscale.gva2.internal │ │ │ │ │ Labels │ n/a │ │ Subnets │ - │ ┼──────────────┼────────────────────────────────────────────────────────────┼ ``` Then you can create a subnet and attach an instance to it. ```console $ exo networking vpc subnet create my-vpc my-subnet --address-family inet4 --address-space private --ipv4-block 10.0.0.0/24 ✔ Creating Subnet "my-subnet"... 0s ┼────────────────┼──────────────────────────────────────┼ │ VPC SUBNET │ │ ┼────────────────┼──────────────────────────────────────┼ │ ID │ 22a213de-8805-4d85-a0d2-ec0f01833bc6 │ │ Name │ my-subnet │ │ Description │ │ │ Zone │ ch-gva-2 │ │ Created At │ 2026-10-27 15:52:55 +0000 UTC │ │ Address Family │ inet4 │ │ Address Space │ private │ │ IPv4 Block │ 10.0.0.0/24 │ │ Labels │ n/a │ │ Instances │ - │ ┼────────────────┼──────────────────────────────────────┼ $ exo compute instance attach-to-subnet my-instance my-vpc my-subnet ✔ Attaching instance "my-instance" to Subnet "my-subnet"... 3s ┼─────────────────────────────────────────┼──────────────────────────────────────┼ │ COMPUTE INSTANCE │ │ ┼─────────────────────────────────────────┼──────────────────────────────────────┼ │ ID │ 325b1bc1-5867-4c28-8aa0-d4ed49441e8f │ │ Name │ my-instance │ │ Creation Date │ 2026-10-27 15:50:18 +0000 UTC │ │ Instance Type │ standard.medium │ │ Template │ Linux Ubuntu 26.04 LTS 64-bit │ │ Zone │ ch-gva-2 │ │ Anti-Affinity Groups │ n/a │ │ Deploy Target │ - │ │ Security Groups │ default │ │ Private Instance │ No │ │ Elastic IPs │ n/a │ │ Public IP │ inet4 │ │ IP Address │ 85.217.162.215 │ │ IPv6 Address │ - │ │ Vpc │ my-vpc │ │ Vpc Subnets │ my-subnet 10.0.0.143 │ │ Private Networks │ n/a │ │ Ip Forwarding │ false │ │ SSH Keys │ mykey │ │ Disk Size │ 50 GiB │ │ State │ running │ │ Labels │ n/a │ │ Secure Boot │ false │ │ Tpm │ false │ │ Reverse DNS │ │ │ Application-Consistent Snapshot enabled │ false │ ┼─────────────────────────────────────────┼──────────────────────────────────────┼ ``` Finally you can verify that the DHCP options are correctly propagated to the instances. For instances using systemd-networkd as network manager you can do: ```console $ networkctl status eth1 ● 3: eth1 Link File: /usr/lib/systemd/network/99-default.link Network File: /run/systemd/network/zzzz-dracut-default.network State: routable (configured) Online state: online Type: ether Path: pci-0000:00:06.0 Driver: virtio_net Vendor: Red Hat, Inc. Model: Virtio network device Alternative Names: enp0s6 ens6 enx0e000006432f Hardware Address: 0e:00:00:06:43:2f MTU: 1500 (min: 68, max: 65535) QDisc: mq IPv6 Address Generation Mode: eui64 Number of Queues (Tx/Rx): 2/2 Auto negotiation: no Address: 10.0.0.143 (DHCPv4 via 10.0.0.1) fe80::c00:ff:fe06:432f DNS: 8.8.8.8 1.1.1.1 Search Domains: myorg.internal exoscale.gva2.internal NTP: 162.159.200.1 216.239.35.0 Activation Policy: up Required For Online: yes DHCPv4 Client ID: 0e:00:00:06:43:2f DHCPv6 Client DUID: DUID-EN/Vendor:0000ab11b02448dc497bb0e5 Oct 27 15:54:11 my-instance systemd-networkd[1004]: eth1: Configuring with /run/systemd/network/zzzz-dracut-default.network. Oct 27 15:54:11 my-instance systemd-networkd[1004]: eth1: Link UP Oct 27 15:54:11 my-instance systemd-networkd[1004]: eth1: Gained carrier Oct 27 15:54:11 my-instance systemd-networkd[1004]: eth1: DHCPv4 address 10.0.0.143/32 acquired from 10.0.0.1 Oct 27 15:54:13 my-instance systemd-networkd[1004]: eth1: Gained IPv6LL ``` ## Set DHCP Options of an existing VPC > [!WARNING] > For the moment, you can only update DHCP Options on VPCs with no instance attached. > Support for all VPCs is coming soon. ```console # Update the VPC to keep only one domain search $ exo networking vpc update my-vpc --domain-search myorg.internal ┼──────────────┼─────────────────────────────────────────────────┼ │ VPC │ │ ┼──────────────┼─────────────────────────────────────────────────┼ │ ID │ ebd4b6c9-3a10-4850-983f-2411b650fa1f │ │ Name │ my-vpc │ │ Description │ │ │ Default │ false │ │ Zone │ ch-gva-2 │ │ Created At │ 2026-10-27 15:32:22 +0000 UTC │ │ DHCP options │ │ │ │ DNS Servers 8.8.8.8, 1.1.1.1 │ │ │ NTP Servers 162.159.200.1, 216.239.35.0 │ │ │ Domain Search myorg.internal │ │ │ │ │ Labels │ n/a │ │ Subnets │ │ │ │ my-subnet 10.0.0.0/24 │ │ │ │ ┼──────────────┼─────────────────────────────────────────────────┼ ``` ## Limits The DHCP options are subject to the following limits per VPC: - DNS Servers: maximum 5 allowed. - NTP Servers: maximum 5 allowed. - Domain Search List: limited to 255 octets post RFC3397 compression.