We have noticed an issue on v7.6 and 7.7RC3 where IPv6 OSPF does not seem to use the cost on interfaces when setting up routes.
We have 80+ routers with 2 connections, one to each core with a cost of 20. The cores are also connected to each other with a cost of
5. The cores are then connected to our edge routers with a cost of 10.
IPv4 routing table shows 1 route for each one of our networks in the core, pointing back to the respective router attached to it.
IPv6 shows a route back to the respective router and an OSPFv3 route pointed back to each and every other router. You can imagine how big our routing tables get before OSPFv3 crashes on the core routers. All the alternative routes show up as ECMP. Usually the distance is 110 for the OSPFv3 routes and 0 for the directly attached ones but by using traceroutes, we have noticed half of our traffic is getting redirected across the OSPFv3 routes and not the directly attached ones. That traffic gets stuck bouncing between the wrong routers and the cores until it finally dies. We are not sure what is causing this or how to keep it from happening. Also, when OSPFv3 does crash with too many routes, OSPF crashes also.
Code: Select all
Core
/routing ospf instance
add disabled=no name=ospf-v2 router-id=100.78.0.3
add disabled=no name=ospf-v3 router-id=100.78.0.3 version=3
/routing ospf area
add disabled=no instance=ospf-v2 name=ospfv2
add disabled=no instance=ospf-v3 name=ospfv3
/routing ospf interface-template
add area=ospfv2 disabled=no interfaces=LoopBack networks=100.78.0.3/32 passive
add area=ospfv3 disabled=yes interfaces=LoopBack networks=XXXX:XXXX::78:0:3/128 passive
#Crossoconnect to other core
add area=ospfv2 cost=5 disabled=no interfaces=qsfp28-2-1 networks=100.76.0.72/30 type=ptp
add area=ospfv3 cost=5 disabled=yes interfaces=qsfp28-2-1 networks=XXXX:XXXX::76:18:0/112 type=ptp
#Uplink to Edge Router
add area=ospfv2 cost=10 disabled=no interfaces=vlan901 networks=100.77.0.68/30 type=ptp
add area=ospfv3 cost=10 disabled=yes interfaces=vlan901 networks=XXXX:XXXX::77:17:0/112 type=ptp
#Link to customer router
add area=ospfv2 cost=20 disabled=no interfaces=vlan3364 networks=100.77.1.0/30 type=ptp
add area=ospfv3 cost=20 disabled=yes interfaces=vlan3364 networks=XXXX:XXXX::77:64:0/112 type=ptp
Customer router
/routing ospf instance
add disabled=no name=default-v2 out-filter-chain=ospfv2-out router-id=100.78.0.58
add disabled=no name=default-v3 out-filter-chain=ospfv3-out router-id=100.78.0.58 version=3
/routing ospf area
add disabled=no instance=default-v2 name=backbone-v2
add disabled=no instance=default-v3 name=ospf-v3
add area-id=0.0.0.2 disabled=no instance=default-v2 name=ospfv2_2
/routing ospf interface-template
add area=backbone-v2 auth-id=1 auth-key="" cost=10 disabled=no interfaces=LoopBack networks=100.78.0.58/32 passive priority=1
add area=backbone-v2 auth-id=1 auth-key="" cost=10 disabled=no interfaces=vlan3164 networks=100.76.1.0/30 priority=1 type=ptp
add area=backbone-v2 auth-id=1 auth-key="" cost=10 disabled=no interfaces=vlan3364 networks=100.77.1.0/30 priority=1 type=ptp
add area=ospf-v3 disabled=no interfaces=LoopBack networks=XXXX:XXXX::78:0:58/128 passive
add area=ospf-v3 disabled=no interfaces=vlan3164 networks=XXXX:XXXX::76:64:0/112 type=ptp
add area=ospf-v3 disabled=no interfaces=vlan3364 networks=XXXX:XXXX::77:64:0/112 type=ptp