In certain cases, GRE interfaces are missing the "RUNNING" flag at bootup and will not function
Still trying to gather information but this has been directly observed on a customer system.
GRE tunnel configured and an interface assigned, with IP configured. The gre0 interface is marked "UP" at boot time but it does NOT have the "RUNNING" flag. In this state, the GRE tunnel will not accept nor initiate traffic over the tunnel. If you run "ifconfig gre0 up" it will then have the RUNNING flag and function as expected.
So far I have not been able to reproduce this in a VM, but it seems to only affect 2.1 and was not a problem on 2.0.
In the observed problem case, the GRE interface was configured, assigned with an IP set, gateway configured, and the GRE gateway was set as the default gateway. There was a static route set to reach the far-side GRE endpoint via a different local gateway. pf was disabled.
Workaround: Adding a shellcmd to "ifconfig gre0 up" at boot time allows it to function.
Updated by Chris Buechler over 7 years ago
- Status changed from Resolved to New
- Target version changed from 2.1.1 to 2.2
Have a config from a customer that can replicate on all 2.1x versions. In projects git repo, redmine-3281.xml. That's a slightly modified customer config, changing the tunnel endpoint IPs to private IPs so it's not possible to bring up that config and potentially mess with their production setup. It has 5 GRE tunnels in that config, none of which get the RUNNING flag at boot time.
Root cause of this seems to be:
Updated by James Field over 6 years ago
I have 2.2-RC (amd64) built on Fri Jan 09 09:55:04 CST 2015 FreeBSD 10.1-RELEASE-p3 installed on Hyper-v 2012 R2
I am currently experiencing this issue, after a reboot the GRE tunnel is "up" but not "running". I need to type ifconfig gre0 up at the shell to get the tunnel working.