• We created a fti interface and tunnels on lab router. Example of the fti0.27

labroot@jtac-mx10003-re0> show configuration interfaces fti0 unit 27 
tunnel {
  encapsulation vxlan-gpe {
    source {
      address 10.2.146.131;
    }
    destination {
      address 40.84.7.168;
    }
    tunnel-endpoint vxlan;
    destination-udp-port 65330;
    vni 972876;
  }
}
family inet {
  address 130.151.36.7/28;
}
family inet6;

• Next, we deleted the same config using the following commands-

delete interfaces fti0 unit 27 tunnel encapsulation vxlan-gpe source address 10.2.146.131
delete interfaces fti0 unit 27 tunnel encapsulation vxlan-gpe destination address 40.84.7.168
delete interfaces fti0 unit 27 tunnel encapsulation vxlan-gpe tunnel-endpoint vxlan
delete interfaces fti0 unit 27 tunnel encapsulation vxlan-gpe destination-udp-port 65330
delete interfaces fti0 unit 27 tunnel encapsulation vxlan-gpe vni 972876
delete interfaces fti0 unit 27 family inet address 130.151.36.7/28
delete interfaces fti0 unit 27 family inet6

• When trying to delete the fti interface and tunnels in the reverse order of set statements of config, customer was seeing error.

labroot@jtac-mx10003-re0# commit check 
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'source'                         <<<<<------------
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'destination'                    <<<<<------------
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'tunnel-endpoint'
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'destination-udp-port'
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'vni'
error: configuration check-out failed: (missing mandatory statements)

• But instead of all these delete commands, if you directly delete the fti interafce unit 27, it will be accepted.

[edit]
labroot@jtac-mx10003-re0# delete interfaces fti0 unit 27 

[edit]
labroot@jtac-mx10003-re0# show | compare 
[edit interfaces fti0]
-  unit 27 {
-    tunnel {
-      encapsulation vxlan-gpe {
-        source {
-          address 10.2.146.131;
-        }
-        destination {
-          address 40.84.7.168;
-        }
-        tunnel-endpoint vxlan;
-        destination-udp-port 65330;
-        vni 972876;
-      }
-    }
-    family inet {
-      address 130.151.36.7/28;
-    }
-    family inet6;
-  }
 

[edit]
labroot@jtac-mx10003-re0# commit check 
configuration check succeeds                                        <<<<<------------

• To understand it more, I just configured a single parameter for fti0.27 - the tunnel encapsulation to vxlan-gpe and tried to commit, it threw me the same error.

labroot@jtac-mx10003-re0# set interfaces fti0 unit 27 tunnel encapsulation vxlan-gpe 

 
[edit]
labroot@jtac-mx10003-r2007-re0# commit check 
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'source'
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'destination'
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'tunnel-endpoint'
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'destination-udp-port'
[edit interfaces fti0 unit 27 tunnel encapsulation]
 'vxlan-gpe'
  Missing mandatory statement: 'vni'
error: configuration check-out failed: (missing mandatory statements)

• This is because in case of fti tunnels, all these parameters have to be mandatorily configured else the configuration is invalid.
• So, setting just the tunnel encap throws error as rest of the parameters are not set.
• Likewise, deleting the single source address will throw the error that rest parameters are not included.

Solution:

• Delete the complete tunnel instead of deleting each parameter. Example- delete interfaces fti0 unit 27