mannetworkingReviewed July 15, 2026

DHCP, DNS, and libvirt virtual networks

Managed libvirt networks can provide bridge creation, DHCP, DNS, NAT, and firewall integration. Libvirt launches scoped dnsmasq instances from network XML. Inspect the network service Persistent reservation Use a stable

dnsmasqdhcpdnsleases

Managed libvirt networks can provide bridge creation, DHCP, DNS, NAT, and firewall integration. Libvirt launches scoped dnsmasq instances from network XML.

Inspect the network service

BASH

virsh net-list --all
virsh net-info default
virsh net-dumpxml default
virsh net-dhcp-leases default
ps -ef | grep '[d]nsmasq.*libvirt'

Persistent reservation

Use a stable guest MAC and a <host> entry in the network DHCP range. Apply changes with virsh net-update when supported, or redefine and restart in a controlled window.

Failure isolation

BASH

ip address show virbr0
ss -lunp | grep -E ':53|:67'
journalctl -u virtnetworkd -u libvirtd --since -30m
nft list ruleset

Differentiate a missing lease, DNS failure, bridge failure, forwarding policy, and guest firewall. They produce similar symptoms from inside the VM but require different repairs.

mannetworkingReviewed July 15, 2026

DHCP, DNS, and libvirt virtual networks

dnsmasqdhcpdnsleases

Managed libvirt networks can provide bridge creation, DHCP, DNS, NAT, and firewall integration. Libvirt launches scoped dnsmasq instances from network XML.

Inspect the network service

BASH

virsh net-list --all
virsh net-info default
virsh net-dumpxml default
virsh net-dhcp-leases default
ps -ef | grep '[d]nsmasq.*libvirt'

Persistent reservation

Use a stable guest MAC and a <host> entry in the network DHCP range. Apply changes with virsh net-update when supported, or redefine and restart in a controlled window.

Failure isolation

BASH

ip address show virbr0
ss -lunp | grep -E ':53|:67'
journalctl -u virtnetworkd -u libvirtd --since -30m
nft list ruleset

Differentiate a missing lease, DNS failure, bridge failure, forwarding policy, and guest firewall. They produce similar symptoms from inside the VM but require different repairs.