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Overview

The DHCP agent provides IP address assignment, DNS resolver delivery, and host route injection for tenant subnets. Multiple DHCP agents can serve the same network for high availability — when the active agent fails, a standby takes over without disrupting existing DHCP leases.
Administrator Access Required — This operation requires the admin role. Contact your Xloud administrator if you do not have sufficient permissions.
Prerequisites
  • Admin credentials sourced from admin-openrc.sh
  • At least one running DHCP agent (verify with openstack network agent list --agent-type dhcp)

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View Networks Served by an Agent

Log in to the Xloud Dashboard (https://connect.<your-domain>) as an administrator and navigate to Admin → Network → Agents. Click the agent ID of a DHCP agent. The Networks tab lists all networks this agent is currently serving.

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Schedule a Network to a DHCP Agent

Navigate to Admin → Network → Agents, click a DHCP agent, then click Add Network in the Networks tab. Select the network from the list.

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Remove a Network from an Agent

Remove network from a specific DHCP agent
openstack network agent remove network --dhcp <agent-id> <network-id>
Remove the network from a DHCP agent only after confirming another healthy agent is serving it. Run openstack network list --agent <standby-agent-id> to verify the standby agent shows the network before removing the primary.

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DHCP Agent HA Architecture

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Troubleshoot DHCP Issues

Cause: DHCP agent is down, subnet DHCP is disabled, or allocation pool is exhausted.Resolution:
  1. Confirm DHCP is enabled on the subnet:
    Check subnet DHCP status
    openstack subnet show <subnet-name> -f json | grep enable_dhcp
  2. Verify the DHCP agent is alive:
    Check DHCP agent health
    openstack network agent list --agent-type dhcp
  3. Check the allocation pool size vs. current port count:
    Count ports on network
    openstack port list --network <network-name> | wc -l
Cause: Subnet DNS or gateway was updated but running instances have stale DHCP leases.Resolution: Force DHCP renewal on the affected instance:
Renew DHCP lease on Linux guest
sudo dhclient -r eth0 && sudo dhclient eth0
Alternatively, restart the network interface or reboot the instance.

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Next Steps

Network Agent Management

Monitor and manage the full set of SDN agents across your cluster

Subnets

Configure DHCP allocation pools, DNS, and host routes at the subnet level

DNS Configuration

Control DNS resolver delivery to instances through DHCP

Admin Troubleshooting

Resolve agent and connectivity issues with diagnostic commands