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When Junos places a GRE interface into a custom virtual router, the VR routing table needs a static route for the remote tunnel endpoint (external host) towards the main routing instance (inet.0).

Below is a GRE tunnel between local IP 1.1.1.1 from interface ge-1/0/1.0 placed in inet.0 and some host on the internet: 2.2.2.2.

The GRE interface (gr-0/0/0.0) is placed in the "CUSTOM-VR" virtual router and a static route for 2.2.2.2 towards inet.0 is also designated.

[code]user@junos# top show interfaces gr-0/0/0.0
clear-dont-fragment-bit;
point-to-point;
tunnel {
source 1.1.1.1;
destination 2.2.2.2;
allow-fragmentation;
}
family inet {
mtu 1500;
address 172.16.0.34/30;
}

[edit routing-instances CUSTOM-VR]
user@junos# show
instance-type virtual-router;
interface gr-0/0/0.0;
routing-options {
static {
route 2.2.2.2/32 next-table inet.0;
}
autonomous-system 65520;
instance-import CUSTOM-VR-VR-direct;
}[/code]