eth0 default route metric (200) overrides col0 (300) after DHCP lease

[viswatejan]

Description

I am not able to pull images due to the routing conflict. I always have to restart the colima instance to pull the images.

Details:
I am seeing a routing conflict where the eth0 interface is assigned a default route with a lower metric than col0. This causes the VM to lose internet connectivity (or route through the wrong interface).

Reproduction Steps:

1. Start Colima with --network-address.
2. Wait for a DHCP lease or network change.
3. Run ip route inside the VM.

Actual Behavior:
Two default routes exist, but eth0 has a metric of 200, making it the preferred path over col0 (metric 300).

Routing Table (After Issue):

default via 192.168.5.2 dev eth0 proto dhcp src 192.168.5.1 metric 200
default via 192.168.0.1 dev col0 proto dhcp src 192.168.0.78 metric 300

Suggested Fix:
Ensure that the col0 interface is always assigned a lower metric (e.g., 50 or 100) or ensure eth0 is configured with ipv4.never-default or a significantly higher metric.

Version

colima version 0.10.1
git commit: ed90520

runtime: docker
arch: aarch64
client: v29.3.1
server: v29.2.1
limactl version 2.1.1
zsh: command not found: qemu-img

Operating System

• macOS Intel <= 13 (Ventura)
• macOS Intel >= 14 (Sonoma)
• Apple Silicon <= 13 (Ventura)
• Apple Silicon >= 14 (Sonoma)
• Linux

Output of colima status

colima status
INFO[0000] colima is running using macOS Virtualization.Framework
INFO[0000] arch: aarch64
INFO[0000] runtime: docker
INFO[0000] mountType: virtiofs
INFO[0000] address: 192.168.0.78
INFO[0000] docker socket: unix:///Users//.colima/default/docker.sock
INFO[0000] containerd socket: unix:///Users//.colima/default/containerd.sock

Reproduction Steps

1. Start Colima with --network-address.
2. Wait for a DHCP lease or network change.
3. Run ip route inside the VM.

Expected behaviour

col0 should be the preferred route always.

Additional context

No response

[abiosoft]

Try with --network-preferred-route.

colima start --network-address --network-preferred-route

[viswatejan]

Seems like that fixed it. Thank you!

[viswatejan]

The following is the exact command using to start the colima instance and the issues seems happening after a while:

colima start \                                                          
    --cpu 4 --memory 8 --disk 48 \
    --vm-type vz --vz-rosetta \
    --network-mode bridged --network-interface en1 --network-address --network-preferred-route \
    --dns 1.1.1.1 --dns 8.8.8.8 \
    --mount-type virtiofs  \
    --verbose

Logs:

Error response from daemon: failed to resolve reference "ghcr.io/immich-app/immich-machine-learning:v2.7.3": failed to do request: Head "https://ghcr.io/v2/immich-app/immich-machine-learning/manifests/v2.7.3": dial tcp 140.82.113.33:443: connect: network is unreachable.

colima ssh -- ip route
default via 192.168.0.1 dev col0 proto dhcp src 192.168.0.78 metric 100
default via 192.168.5.2 dev eth0 proto dhcp src 192.168.5.1 metric 200
68.105.28.11 via 192.168.0.1 dev col0 proto dhcp src 192.168.0.78 metric 100
68.105.29.11 via 192.168.0.1 dev col0 proto dhcp src 192.168.0.78 metric 100
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown
172.18.0.0/16 dev br-e016664112f7 proto kernel scope link src 172.18.0.1
172.19.0.0/16 dev br-e13f971812cb proto kernel scope link src 172.19.0.1
172.20.0.0/16 dev br-30e305a28b7c proto kernel scope link src 172.20.0.1
192.168.0.0/24 dev col0 proto kernel scope link src 192.168.0.78 metric 100
192.168.0.1 dev col0 proto dhcp scope link src 192.168.0.78 metric 100
192.168.5.0/24 dev eth0 proto kernel scope link src 192.168.5.1 metric 200
192.168.5.2 dev eth0 proto dhcp scope link src 192.168.5.1 metric 200

colima ssh -- cat /etc/resolv.conf
# Generated by Colima
nameserver 192.168.5.1

colima ls
PROFILE STATUS ARCH CPUS MEMORY DISK RUNTIME ADDRESS
default Running aarch64 4 8GiB 48GiB docker 192.168.0.78

colima status
INFO[0000] colima is running using macOS Virtualization.Framework
INFO[0000] arch: aarch64
INFO[0000] runtime: docker
INFO[0000] mountType: virtiofs
INFO[0000] address: 192.168.0.78
INFO[0000] docker socket: unix:///Users/userid/.colima/default/docker.sock
INFO[0000] containerd socket: unix:///Users/userid/.colima/default/containerd.sock