I have a cluster of instances in Google Cloud Platform that was accessible. I ran updates on a VM, then rebooted it. I have not been able to access the VM since. SSH fails, saying it cant be reached. I also cannot ping the instance. When I connect via the console port, it is flooded with martian source logs.

martian source x.x.x.x <affected machine> from x.x.x.x <some other ip>, on dev eth0
ll header: 42:01:0a:8e:00:05:42:01:0a:8e:00:01:08:00
Jul 11 20:07:40 <servername> kernel: __ratelimit: 3 callbacks suppressed

It is only affecting the machines that have been updated and rebooted. The ones that have been updated but NOT rebooted are fine (so far). I also checked the firewall-rules, and there is the default SSH rule.

I did find that if I clone an affected VM and give it a new OS disk, I can access it afterwards.

Any ideas? I am at a loss as to what to do with the ones that have been (and have not been) updated.


I found the fix for me. A recent update has a known issue where it removes the default gateway from the iptables. To fix it, I have to go to the instance and select Edit. Scroll down, and under Custom Metadata put the following:

key: startup-script
value: route add default gw <gatewayIP> eth0

Save and restart the VM.

  • It took me a bit to figure this out - the IP of the Default Gateway is the second address in the primary IP range for the subnet. For example, if the primary IP range is, then the Default Gateway IP is VPC docs Oct 28 '18 at 19:24

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