Learn DragonFlyBSD - Networking & Network Configuration

#Introduction

In episode 9 you created snapshots, dedup, and encryption on HAMMER2. Now we move to another dimension: getting this system to talk to the outside world. Networking is the lifeblood of modern servers — without correct network configuration, there's no SSH, no services, no remote management.

DragonFlyBSD handles networking in a distinctly BSD way: all persistent configuration lives in /etc/rc.conf, while direct operations are done with ifconfig and route. What's interesting is what runs beneath the surface: newbee — the custom network stack that's one of the architectural differentiators of DragonFlyBSD.

#Basic Network Configuration

#Interfaces in /etc/rc.conf

All persistent network configuration is written in /etc/rc.conf. Variable names follow the ifconfig_<interface> pattern. For DHCP:

ifconfig_em0="DHCP"

For a static address, include the IP address, netmask, and broadcast:

ifconfig_em0="inet 192.168.1.10 netmask 255.255.255.0"
defaultrouter="192.168.1.1"

defaultrouter sets the default gateway. After writing it, apply the configuration by restarting the network or rebooting:

service netif restart
service routing restart

#ifconfig: Viewing and Configuring Interfaces

ifconfig is the main tool for inspecting and changing interfaces directly:

ifconfig
ifconfig em0
ifconfig em0 inet 192.168.1.10 netmask 255.255.255.0

ifconfig without arguments shows all active interfaces; ifconfig em0 details a single one. Changes made with ifconfig are temporary — for persistence they must be written in rc.conf.

#route: The Routing Table

Viewing and managing the routing table:

route show
route add default 192.168.1.1
route delete default 192.168.1.1

route show displays the routing table; route add default sets the gateway. Most routing changes can be described in one sentence: "packets that don't know their destination are sent to the gateway."

#/etc/resolv.conf: DNS

Name resolution is handled by /etc/resolv.conf:

nameserver 1.1.1.1
nameserver 8.8.8.8
search internal.example.com

When using DHCP, this file is usually filled in automatically. For static configuration, write it manually. Verify resolution with:

ping -c 2 dragonflybsd.org
host dragonflybsd.org

#The Custom Network Stack: newbee

Working beneath these familiar commands is newbee — DragonFlyBSD's custom network stack project. Its goal: replace the legacy network stack with a more modern design that's easier to understand and better supports virtualization and tunneling features. As an administrator, you don't see newbee directly — ifconfig, route, and standard tooling are still used. What you feel is stability and flexibility in advanced network scenarios, especially those involving the bridge, VLAN, and tunneling we're about to discuss.

#Advanced Interfaces

#Interface Aliases

One physical interface can hold many IP addresses — useful for multi-vhost hosting on a single NIC:

ifconfig em0 alias 192.168.1.11/24

In rc.conf, add several ifconfig_em0_aliasN lines with increasing indexes.

#VLAN

VLANs split one physical switch into many logical networks. A VLAN interface is created by riding on top of a physical interface:

ifconfig vlan10 create
ifconfig vlan10 vlan 10 vlandev em0
ifconfig vlan10 inet 192.168.10.2/24

In rc.conf, register the vlan interfaces:

cloned_interfaces="vlan10"
ifconfig_vlan10="vlan 10 vlandev em0 inet 192.168.10.2/24"

#lagg: Bonding

lagg combines several NICs into one link for redundancy and bandwidth:

ifconfig lagg0 create
ifconfig lagg0 laggproto failover laggport em0 laggport em1
ifconfig lagg0 inet 192.168.1.10/24

The failover mode is active-standby; loadbalance mode spreads the load. This is the foundation for reliable production networking — we'll dig into it in episode 16.

#bridge: Connecting Interfaces

A bridge connects interfaces transparently, like a software switch — the basis for virtualization (episode 18) and home networking devices:

ifconfig bridge0 create
ifconfig bridge0 add em0 add tap0
ifconfig bridge0 up

#IPv6

DragonFlyBSD has full IPv6 support. Configuration in rc.conf uses the inet6 form:

ifconfig_em0_ipv6="inet6 accept_rtadv"
ifconfig_em0="inet6 2001:db8::10/64"

With accept_rtadv, your IPv6 address is taken from router advertisements (SLAAC) — the most common way to get IPv6 on modern networks.

#Closing

In this episode 10 you mastered basic DragonFlyBSD networking: DHCP and static interface configuration in /etc/rc.conf, ifconfig and route operations, laying out /etc/resolv.conf, an introduction to the newbee network stack, plus interface aliases, VLAN, lagg bonding, bridge, and IPv6.

Key takeaways:

• ifconfig_<if> variables in /etc/rc.conf store the configuration; defaultrouter sets the gateway.
• ifconfig for inspection and direct changes; route show for the routing table.
• /etc/resolv.conf handles DNS; ping and host for verification.
• newbee is the custom network stack working behind familiar tooling.
• VLAN, lagg, and bridge extend a single NIC's capabilities — the key to production networking.

In the next episode, episode 11, we return to data: data management & backup. You'll care for the filesystem with hammer2 info, hammer2 status, and fsck_hammer2, get to know dump/restore, then build a backup strategy with HAMMER2 snapshots, hammer2 send, tar, and rsync.