Modifying Network Configuration¶

This page documents the f5insight-netconfig utility and common workflows for managing host network settings.

Overview¶

Use f5insight-netconfig when you need to update management networking from the command line, especially during initial deployment or recovery scenarios.

Primary Use Case: Set Static IPv4 Without DHCP¶

Use this workflow when your environment does not provide DHCP and you must assign a fixed management IP.

Before You Start¶

Run these commands from the F5 Insight host console or over SSH.
Collect required values from your network team:
- Static IPv4 address and prefix length (example: 192.0.2.54/24)
- Default gateway (example: 192.0.2.1)
- One or more DNS servers (example: 203.0.113.53 203.0.113.54)

Example Command¶

sudo f5insight-netconfig set-static \
  --ipv4 192.0.2.54/24 \
  --ipv4-gateway 192.0.2.1 \
  --dns 203.0.113.53

Sample output:

[2026-03-11 15:22:00] Setting static IP configuration...
[2026-03-11 15:22:00]   Interface: ens3
[2026-03-11 15:22:00]   IPv4: 192.0.2.54/24
[2026-03-11 15:22:00]   IPv4 Gateway: 192.0.2.1
[2026-03-11 15:22:00]   IPv6: none
[2026-03-11 15:22:00]   IPv6 Gateway: none
[2026-03-11 15:22:00]   DNS: 203.0.113.53
[2026-03-11 15:22:00] Generated IPv4 config: /etc/netplan/61-f5insight-ipv4.yaml

================================================
New network configuration:
  IPv4: 192.0.2.54/24 (gateway: 192.0.2.1)
  DNS:  203.0.113.53
================================================

Apply these settings? [y/N] y
[2026-03-11 15:22:02] Applying network configuration...
System will be available at 192.0.2.54
[2026-03-11 15:22:07] Updating K3s node-ip configuration...
[2026-03-11 15:22:07] K3s configuration updated successfully
[2026-03-11 15:22:07] Network configuration confirmed and saved.

================================================
Network configuration confirmed!
The new settings are now permanent.
[2026-03-11 15:22:07] Restarting K3s to apply new node-ip...
K3s has been restarted with the new node-ip.
================================================

After set-static, the utility prompts for confirmation before applying changes.

If your build uses different flags, check:

f5insight-netconfig --help

Verify The Change¶

Review the active configuration:

sudo f5insight-netconfig show

Sample output:

Current network configuration:
  IPv4: 192.0.2.54/24
  IPv4 Gateway: 192.0.2.1
  IPv6: none
  DNS: 203.0.113.53

Confirm the new address on the host:

ip -4 addr

Sample output:

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    inet 192.0.2.54/24 brd 192.0.2.255 scope global dynamic ens3
       valid_lft 43199sec preferred_lft 43199sec

Confirm routing:

ip route

Sample output:

default via 192.0.2.1 dev ens3 proto kernel scope link src 192.0.2.54
192.0.2.0/24 dev ens3 proto kernel scope link src 192.0.2.54

Confirm DNS resolution:

getent hosts github.com

Sample output:

140.82.114.3 github.com
140.82.114.4 github.com

Validate SSH reachability from your workstation:

badssh admin@192.0.2.54

Sample output:

Connected to f5-insight01 (192.0.2.54)

Common Additional Use Cases¶

Switch Back To DHCP¶

sudo f5insight-netconfig set-dhcp

Switch To DHCP IPv4 Only¶

sudo f5insight-netconfig set-dhcp4

Switch To DHCP IPv6 Only¶

sudo f5insight-netconfig set-dhcp6

Dual-Stack Static (IPv4 + IPv6)¶

sudo f5insight-netconfig set-static \
  --ipv4 198.51.100.100/24 \
  --ipv4-gateway 198.51.100.1 \
  --ipv6 2001:db8::100/64 \
  --ipv6-gateway 2001:db8::1 \
  --dns 203.0.113.53

Manual Rollback¶

sudo f5insight-netconfig rollback

Troubleshooting¶

If you lose connectivity after applying changes, use the VM console to correct settings.
If an address does not appear, verify the subnet/prefix and gateway values.
If DNS fails, confirm UDP/TCP 53 egress is allowed to the configured resolvers.
If SSH fails to connect to 192.0.2.54, verify local routing and firewall policy between your workstation and that management subnet.

Notes¶

Keep a maintenance window when changing remote management addresses.
Prefer a reserved IP in your management subnet to avoid overlap with other systems.

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