steps to repro:

==============

Create N1(Dualstack),N2(Dual stack)
Create Router and associate all IPv6 subnet to router and verify FIB and data path.
Create L3VPN and associate Router to it and verify data path
Associate all IPv4 subnet to Router and Verify data path
Delete L3VPN alone and verify fib-show.

Though vpn is deleted all entries are displayed vpn-id which ideally should be the router-id as the vpn has got deleted.

 opendaylight-user@root>fib-show
RD Prefix NextHop Label Origin
-------------------------------------------------------------------
1:1 2001:db8:0:2:f816:3eff:fedc:ea45/128 192.168.56.215 100037 l
1:1 2001:db8:0:2::/64 192.168.56.215 100034 c
1:1 2001:db8:0:2::1/128 0.0.0.0 100036 l
1:1 3001:db8:0:3:f816:3eff:fef9:7306/128 192.168.56.215 100040 l
1:1 10.0.0.3/32 192.168.56.215 100045 l
1:1 20.0.0.1/32 0.0.0.0 100047 l
1:1 20.0.0.2/32 192.168.56.215 100048 l
1:1 10.0.0.1/32 0.0.0.0 100043 l
1:1 20.0.0.5/32 192.168.56.215 100049 l
1:1 3001:db8:0:3::/64 192.168.56.215 100035 c
1:1 10.0.0.0/24 192.168.56.215 100042 c
1:1 20.0.0.0/24 192.168.56.215 100046 c
1:1 10.0.0.8/32 192.168.56.215 100044 l
1:1 2001:db8:0:2:f816:3eff:fe7b:533c/128 192.168.56.215 100038 l
1:1 3001:db8:0:3::1/128 0.0.0.0 100039 l
1:1 3001:db8:0:3:f816:3eff:feb3:6f2f/128 192.168.56.215 100041 l
opendaylight-user@root>