This article describes the situation where we see IPv6 Unicast NH for IPv4 service routes representation. There is a display issue with IPv6 over IPv4 underlay. When we have IPv6 over IPv4 underlay, nexthops will be shared by both IPv4 and IPv6 routes.
For example, please refer the show outputs for IPv4 route 2.3.4.0/32 and IPv6 route ::4.3.2.6/128.
The list nexthop is shared between IPv4 and IPv6 hierarchies.
In such case, we can have a display issue in PFE where IPv4 nexthops' address family will be displayed as IPv6. This is because the nexthops are shared and the address family of parent hierarchy is inherited by the children nexthops which are IPv4.Please note that this has no functional impact.
IPv4 RPD Hierarchy:
{master}[edit] root@DUT-VPTX-01_re# run show route 2.3.4.0 extensive expanded-nh inet.0: 73 destinations, 134 routes (73 active, 0 holddown, 0 hidden) 2.3.4.0/32 (4 entries, 1 announced) Installed-nexthop: List (0xd7b4b48) Index:2097255 Indr (0xc63de34) 4.3.2.0 Krt_inh (0xc559b84) Index:2097224 PNH: 4.3.2.0 List (0xd739894) Index:2097315 Chain EVPN (0xc6413b8) Index:704 IPoIP src 10.20.30.40 dest 1.2.3.6-101<c> tunnel-endpoint 1.2.3.6 Frr_inh (0xc64128c) Index:2097266 PNH: 1.2.3.6-101<c> List (0xd7b2ca8) Index:2097179 <==== Shared Unilist Nexthop Frr_inh (0xc64862c) Index:2097177 PNH: 1.1.2.1 List (0xd737054) Index:2097160 Router (0xc649d38) Index:583 81.2.4.4 via et-0/0/1:0.0 Router (0xc6442fc) Index:584 82.2.4.4 via et-0/0/2:0.0 Router (0xc649c70) Index:610 83.2.4.4 via et-1/0/1:0.0 Router (0xc641034) Index:608 84.2.4.4 via et-1/0/2:0.0 Frr_inh (0xc6483d4) Index:2097178 PNH: 1.1.3.1 List (0xd737134) Index:2097165 Router (0xc648f28) Index:586 91.2.4.4 via et-0/0/3:0.0 Router (0xc63971c) Index:585 92.2.4.4 via et-0/0/4:0.0 Router (0xc640d78) Index:611 93.2.4.4 via et-1/0/3:0.0 Router (0xc63f414) Index:612 94.2.4.4 via et-1/0/4:0.0 ::4.3.2.6/128 (4 entries, 1 announced) Installed-nexthop: List (0xd73acb4) Index:2097442 Indr Indexed list (0xc646048) ::ffff:1.2.3.50-112<c6> Krt_cnh (0xbd32cf0) Index:739 IPoIP src 10.20.30.40 dest 1.2.3.50-112<c> tunnel-endpoint 1.2.3.50 Krt_inh (0xc56eb84) Index:2097392 PNH: ::ffff:1.2.3.50-112<c6> List (0xd7b2ca8) Index:2097179 <==== Shared Unilist Nexthop Frr_inh (0xc64862c) Index:2097177 PNH: 1.1.2.1 List (0xd737054) Index:2097160 Router (0xc649d38) Index:583 81.2.4.4 via et-0/0/1:0.0 Router (0xc6442fc) Index:584 82.2.4.4 via et-0/0/2:0.0 Router (0xc649c70) Index:610 83.2.4.4 via et-1/0/1:0.0 Router (0xc641034) Index:608 84.2.4.4 via et-1/0/2:0.0 Frr_inh (0xc6483d4) Index:2097178 PNH: 1.1.3.1 List (0xd737134) Index:2097165 Router (0xc648f28) Index:586 91.2.4.4 via et-0/0/3:0.0 Router (0xc63971c) Index:585 92.2.4.4 via et-0/0/4:0.0 Router (0xc640d78) Index:611 93.2.4.4 via et-1/0/3:0.0 Router (0xc63f414) Index:612 94.2.4.4 via et-1/0/4:0.0 root@DUT-VPTX-01_re# run request pfe execute command "show nhdb id 2097442 recursive" target fpc0 SENT: Ukern command: show nhdb id 2097442 recursive 2097442(Unilist, IPv4, ifl:0:-, pfe-id:0) 739(Compst, IPv6, ifl:0:-, pfe-id:0, comp-fn:Tunnel) 2097392(Indirect, IPv6, ifl:74:et-0/0/1:0.0, pfe-id:0, i-ifl:0:-) 2097179(Unilist, IPv4, ifl:0:-, pfe-id:0) <==== Shared Unilist Nexthop 2097177(Indirect, IPv6, ifl:74:et-0/0/1:0.0, pfe-id:0, i-ifl:0:-) <==== Displayed as IPv6 2097160(Unilist, IPv4, ifl:0:-, pfe-id:0) 583(Unicast, IPv6, ifl:74:et-0/0/1:0.0, pfe-id:0) <==== Displayed as IPv6 584(Unicast, IPv6, ifl:75:et-0/0/2:0.0, pfe-id:0) <==== Displayed as IPv6 610(Unicast, IPv6, ifl:81:et-1/0/1:0.0, pfe-id:8) <==== Displayed as IPv6 608(Unicast, IPv6, ifl:82:et-1/0/2:0.0, pfe-id:8) <==== Displayed as IPv6 2097178(Indirect, IPv6, ifl:76:et-0/0/3:0.0, pfe-id:0, i-ifl:0:-) <==== Displayed as IPv6 2097165(Unilist, IPv4, ifl:0:-, pfe-id:0) 586(Unicast, IPv6, ifl:76:et-0/0/3:0.0, pfe-id:0) <==== Displayed as IPv6 585(Unicast, IPv6, ifl:77:et-0/0/4:0.0, pfe-id:0) <==== Displayed as IPv6 611(Unicast, IPv6, ifl:83:et-1/0/3:0.0, pfe-id:8) <==== Displayed as IPv6 612(Unicast, IPv6, ifl:84:et-1/0/4:0.0, pfe-id:8) <==== Displayed as IPv6