Most likely GRE tunnel with local address 0.0.0.0 required a key.
No any tunnel
```
vyos@r1-roll# sudo ip tunnel show
[edit]
vyos@r1-roll#
```
Config:
```
set interfaces tunnel tun1 encapsulation gre
set interfaces tunnel tun1 source-address '0.0.0.0'
set interfaces tunnel tun1 address 10.10.10.1/30
set interfaces tunnel tun1 multicast 'enable'
```
Commit:
```
vyos@r1-roll# commit
Traceback (most recent call last):
File "/usr/libexec/vyos/conf_mode/interfaces-tunnel.py", line 155, in <module>
apply(c)
File "/usr/libexec/vyos/conf_mode/interfaces-tunnel.py", line 145, in apply
tun = TunnelIf(**tunnel)
File "/usr/lib/python3/dist-packages/vyos/ifconfig/tunnel.py", line 109, in __init__
super().__init__(ifname, **kargs)
File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 269, in __init__
self._create()
File "/usr/lib/python3/dist-packages/vyos/ifconfig/tunnel.py", line 134, in _create
self._cmd(cmd.format(**self.config))
File "/usr/lib/python3/dist-packages/vyos/ifconfig/control.py", line 51, in _cmd
return cmd(command, self.debug)
File "/usr/lib/python3/dist-packages/vyos/util.py", line 161, in cmd
raise OSError(code, feedback)
PermissionError: [Errno 1] failed to run command: ip tunnel add tun1 mode gre local 0.0.0.0 tos inherit ttl 64
returned:
exit code: 1
noteworthy:
cmd 'ip tunnel add tun1 mode gre local 0.0.0.0 tos inherit ttl 64'
returned (out):
returned (err):
add tunnel "gre0" failed: File exists
[[interfaces tunnel tun1]] failed
Commit failed
[edit]
vyos@r1-roll#
[edit]
vyos@r1-roll# sudo ip tunnel show
gre0: gre/ip remote any local any ttl inherit nopmtudisc
[edit]
vyos@r1-roll#
```