failed to set GRE remote IP address after interface was created

It is impossible to change a remote IP address for a GRE interface if it was initially created without specifying a remote address.

E.g. if the interface was created by command "ip tunnel add gre1 mode gre key 123", it is impossible to specify a remote IP address:

"ip tunnel change gre1 remote 1.1.1.1" gives invalid argument error.

I was able to reproduce the behavior in modern Debian and Ubuntu systems.

Is it impossible to change "point-to-point" GRE interface to "point-to-multipoint" and vice versa? I just was unable to find this bug description/ticket.


Alexander Muravev