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Cumulus Linux VRF aware loopback interface


The following article is a quick note to indicate how to define a loopback interface which is VRF aware under Cumulus Linux. The following topic is documented under the VRF section of the Cumulus documentation: https://docs.cumulusnetworks.com/cumulus-linux/Layer-3/Virtual-Routing-and-Forwarding-VRF/

auto test
iface test
    vrf-table auto
    address 2.2.2.2/32
cumulus@switch:~$ net show interface
State  Name           Spd   MTU    Mode          LLDP                Summary
-----  -------------  ----  -----  ------------  ------------------  -------------------------
<snipped>
UP     test		      N/A   65536  VRF                               IP: 2.2.2.2/32
<snipped>

The loopback interface is in fact a VRF interface. The IP is defined under a VRF interface statement. Note that this prefix can be advertised by a routing protocol (like BGP).