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Cloud routers

With a cloud router, you can:

  • route traffic between private subnets. All private subnets connected to the same router can exchange traffic and use the router IP address as a default route;
  • configure internet access for devices in a private subnet (outbound traffic) and from the internet (inbound traffic); for details, see the Configure access to and from the internet instructions. The cloud router performs 1:1 NAT via the external IP address allocated when connecting the router to the internet: it provides internet access from the private subnet and processes inbound traffic packets for public IP addresses.

You can configure static routes on a cloud router.

A cloud router can only be used within one project and one pool.

There are traffic limits for cloud routers — bandwidth. You can view it in the Bandwidth table.

You can work with cloud routers in the control panel, using the OpenStack CLI or Terraform.

Cloud router types

Two router types are available:

  • Basic — consists of one instance. In case of failure, connectivity through the router will be disrupted;

  • With redundancy — consists of primary and backup instances located in different segments of the pool and grouped via VRRP.

    Redundancy works in Active-Passive mode: one instance is active at a time — the primary one; upon failure, traffic switches to the backup instance. Switching takes up to 10 seconds, connections are interrupted and re-established on the backup instance. Instances swap roles — the backup becomes the primary. If the router has a firewall, its settings are preserved.

You can select the router type when creating a router. After creation, you can change its type only via the OpenStack CLI — enable redundancy or disable redundancy.

Create a cloud router

  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to Network → the Cloud Routers tab.
  3. Click Create Router.
  4. Select the location where the cloud router will be created.
  5. Select the router type. You can change the router type after creation — enable redundancy or disable redundancy.
  6. Enter a router name.
  7. Optional: select the Connect router to the internet checkbox — an external IP address will be allocated for the router.
  8. Click Create.

Connect a subnet to a cloud router

For devices in private subnets of the same pool to exchange traffic, the subnets must be connected to the same cloud router. The subnets must not overlap — they must not contain identical IP addresses.

To configure access to and from the internet for devices in private subnets, follow the Configure access to and from the internet instructions.

  1. In the control panel, in the top menu, click Products and select Cloud Servers.

  2. Go to the Network section → the Cloud Routers tab.

  3. Open the router page.

  4. Click Connect Subnet.

  5. Select a private subnet.

  6. Optional: enter the router IP address — any available IP address from the subnet. If you do not specify an IP address, it will be automatically selected from the available subnet addresses.

    For devices in the subnet to access the internet without configuring additional routes, the cloud router's IP address must match the private subnet gateway. If the subnet gateway is already occupied, you will need to configure a static route via the cloud router in the subnet to access the internet.

    You can view the subnet gateway in the control panel: in the top menu, click Products → Cloud Servers → Network → the Private Networks tab → the network page → the Subnets tab → the subnet card → the Automatic Network Settings section → the Subnet Gateway field.

  7. Click Connect.

Disconnect a subnet from a cloud router

You cannot disconnect a subnet from a cloud router if:

  • the router processes traffic for public IP addresses of devices in this subnet;
  • the router has static routes that specify IP addresses in this subnet as the next-hop.
  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to the Network section → Cloud Routers tab.
  3. Open the router page → Ports tab.
  4. In the row of the desired subnet port, click .
  5. Click Delete.

Connect a cloud router to the internet

To configure internet access for devices in a private subnet, the subnet must be connected to a cloud router with internet access. For internet access, the router is connected to an external network (external-network), and an external IP address is allocated for it, through which the router will perform the 1:1 NAT function. The external IP address of the router does not change as long as the router is connected to the internet.

You cannot access devices behind the router from the internet using the router's external IP address. It is only used for devices to access the internet through the router.

To configure access from the internet to devices, use a public IP address or a public subnet; for details, see the Configure access to and from the internet⁠ instructions.

  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to Network → the Cloud Routers tab.
  3. In the cloud router menu, select Connect to internet.

Disconnect a cloud router from the internet

If you disconnect the cloud router from the internet, its external IP address will return to the address pool. After reconnecting, the IP address will change.

A cloud router cannot be disconnected from the internet if it processes traffic for public IP addresses.

  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to Network → the Cloud Routers tab.
  3. In the cloud router menu, select Disconnect from internet.
  4. Click Disconnect.

Assign a firewall to a cloud router port

warning

Inbound and outbound traffic that is not allowed by the cloud firewall rules will be blocked on the cloud router port. Active sessions on the router that are not allowed by the new rules will be terminated.

You cannot assign more than one firewall to a single router port.

  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to Network → the Cloud Routers tab.
  3. Open the cloud router page.
  4. In the row of the private subnet port for which you need to configure traffic filtering, in the Firewall field, click .
  5. Select a firewall.
  6. Click Save.

Detach a firewall from a cloud router port

warning

The cloud firewall rules will no longer apply — all inbound and outbound traffic passing through the cloud router port will be allowed.

  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to Network → the Cloud Routers tab.
  3. Open the router page.
  4. In the row of the private subnet port for which traffic filtering was configured, in the Firewall field, click .
  5. Select No firewall.
  6. Click Save.

Enable cloud router redundancy

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Active sessions on the router will be interrupted for the duration of the operation.

You can enable redundancy. The router type will change to With redundancy, and an additional instance will be added to the router.

  1. Open the OpenStack CLI.

  2. Shut down the cloud router:

    openstack router set <router> --disable

    Specify <router> — name of the cloud router, can be viewed using the openstack router list command.

  3. Enable redundancy. An additional instance will be added to the router:

    openstack router set <router> --ha

    Specify:

    • <router> — ID or name of the cloud router, can be viewed using the openstack router list command;
    • optional: --availability-zone-hint <availability_zone> — pool segments where router instances will be located. The <availability_zone> parameter is a pool segment, for example ru-6a. Specify at least two segments, each in a separate parameter, for example --availability-zone-hint ru-6a --availability-zone-hint ru-6b.

  4. Turn on the cloud router:

    openstack router set --enable <router>

    Specify <router> — ID or name of the router, can be viewed using the openstack router list command.

    Connections that were interrupted when the router was shut down will be restored automatically on its original instance.

Disable cloud router redundancy

warning

Active sessions on the router will be interrupted for the duration of the operation.

You can disable redundancy. The router type will change to Basic, and the router backup instance will be deleted.

  1. Open the OpenStack CLI.

  2. Shut down the cloud router:

    openstack router set <router> --disable

    Specify — name of the cloud router, can be viewed using the <router> openstack router list command.

  3. Disable redundancy. The backup router instance that was inactive before shutdown will be deleted:

    openstack router set <router> --no-ha

    Specify:

    • <router> — ID or name of the cloud router, can be viewed using the openstack router list command.

  4. Turn on the cloud router:

    openstack router set --enable <router>

    Specify <router> — ID or name of the router, can be viewed using the openstack router list command.

    Connections that were interrupted when the router was shut down will be restored automatically.

Turn on a cloud router

  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to Network → the Cloud Routers tab.
  3. In the cloud router card, turn on the router.

Turn off a cloud router

A router cannot be shut down if it processes traffic for a public IP address.

  1. In the control panel, in the top menu, click Products and select Cloud Servers.
  2. Go to Network → the Cloud Routers tab.
  3. In the cloud router card, turn off the router.

Delete a cloud router

  1. In the control panel, in the top menu, click Products and select Cloud Servers.

  2. Go to Network → the Cloud Routers tab.

  3. Disconnect all connected subnets from the router by removing all subnet ports from the router:

    3.1. Open the router page → the Ports tab.

    3.2. In the row of any port, click .

    3.3. Click Delete.

    3.4. Repeat steps 3.2–3.3 for all remaining ports.

  4. In the router menu, select Delete router.

  5. Click Delete.