Failed to send 300 byte long packet over fallback interface.

[William Sharlow]

I just noticed this in my messages log... I get these every 10 seconds.  Is this normal?

May 15 08:13:47 host kernel: Firewall: *UDP_OUT Blocked* IN= OUT=eth0 SRC=10.128.0.2 DST=169.254.XXX.XXX LEN=328...
May 15 08:13:47 host dhclient[466]: DHCPREQUEST on eth0 to 169.254.XXX.XXX port 67
May 15 08:13:47 host dhclient[466]: send_packet: Operation not permitted
May 15 08:13:47 host dhclient[466]: dhclient.c:2688: Failed to send 300 byte long packet over fallback interface.

[Marilu (Cloud Platform Support)]

Hi William,

As per the error message, it appears that you have setup some firewall rules, at instance level, that is blocking outgoing UDP packets to 169.254.XXX.XXX if the size is bigger than 300 bytes.

If the IP address is the 169.254.169.254, that is the metadata server, I'll recommend reviewing your instance's firewalls and consider allowing traffic for it, so your instance can reach this server.

I hope this helps,

Marilu 

[William Sharlow]

Thank you Marilu - I'm running CSF and I was inadvertently blocking the metadata server

On Tuesday, May 16, 2017 at 3:04:28 PM UTC-4, Marilu (Cloud Platform Support) wrote:

Hi William,

As per the error message, it appears that you have setup some firewall rules, at instance level, that is blocking outgoing UDP packets to 169.254.XXX.XXX if the size is bigger than 300 bytes.

If the IP address is the 169.254.169.254, that is the metadata server, I'll recommend reviewing your instance firewalls and consider allowing traffic for it, so your instance can reach this server.

[Bruno M]

Hi,

I had the same problem here. Can VM stay offline if the block continues? My VM stayed off line 2 times and the only record I found in the logs was this.

Thanks