When having VLAN without IPv6 address on L3 enabled switch, no RA is passed through VLAN unless there is IPv6 address assigned to the VLAN. Static assigments however are reachable fine.
Switch(config)#interface Vlan 3 no ipv6 address autoconfig # RA from mikrotik not working ipv6 address autoconfig # RA from mikrotik suddenly starts working no ipv6 address autoconfig # IPMI immediately losts SLAAC IPv6 address and become unresponsive
-> Uplink -> Cisco (L3 routing to VLANs) -> Servers
I receive non routed /27 IPv4 and /48 IPv6 routed via single /64 on uplink (vlan 1). Cisco therefore does IPv6 routing to VLANs, where each VLAN is assigned unique /64 range with RA enabled. Everyone who needs IPv4 is assigned second port with (mode access + vlan 1).
VLAN 3 is however special as it is delegated through mikrotik (firewall) and the same cisco is then used as L2 switch (access vlan 3). In that case traffic passes cisco twice.
-> Uplink -> Cisco -> (Gi0/2 VLAN 2 -> ether1) Mikrotik (ether2 -> Gi0/3 VLAN 3) -> Cisco -> IPMI
IPMI are then connected to VLAN 3 and delegated IPv6 is expected to be managed via mikrotik.
When we connect IPMI directly to mikrotik, it works without any issue.
Switch Ports Model SW Version SW Image ------ ----- ----- ---------- ---------- * 1 52 WS-C3560G-48TS 15.0(2)SE4 C3560-IPSERVICESK9-M
version 15.0 ipv6 unicast-routing interface GigabitEthernet0/1 # uplink port ! interface GigabitEthernet0/2 # ether1 to mikrotik switchport access vlan 2 switchport mode access ! interface GigabitEthernet0/3 # ether2 from mikrotik, which manages IPv6 RA switchport access vlan 3 switchport mode access ! .... interface GigabitEthernet0/27 # Example of server uplink switchport access vlan 10 switchport mode access ! interface GigabitEthernet0/28 # Example of IPMI uplink switchport access vlan 3 switchport mode access ! interface GigabitEthernet0/41 # Example of port with IPv4 switchport access vlan 1 switchport mode access ! ... interface Vlan1 # Uplink VLAN no ip address ipv6 address 2001:db8:0:ffff::1/64 ipv6 nd ra suppress all ! interface Vlan2 # Mikrotik prefix delegation network no ip address ipv6 address 2001:db8:0:1::1/64 ipv6 nd ra suppress all ! interface Vlan3 # IPMI VLAN - IP addresses are managed by mikrotik no ip address ! interface Vlan10 # VLAN for servers no ip address ipv6 address 2001:db8:0:10::1/64 ipv6 nd managed-config-flag ipv6 nd other-config-flag ipv6 dhcp relay destination ....... ! ... ipv6 route 2001:db8:0:3::/64 2001:db8:0:1::2 # Prefix delegation to mikrotik ipv6 route ::/0 2001:db8:0:ffff::2 ipv6 address autoconfig
show sdm prefer
The current template is "desktop IPv4 and IPv6 routing" template. The selected template optimizes the resources in the switch to support this level of features for 8 routed interfaces and 1024 VLANs. number of unicast mac addresses: 1.5K number of IPv4 IGMP groups + multicast routes: 1K number of IPv4 unicast routes: 2.75K number of directly-connected IPv4 hosts: 1.5K number of indirect IPv4 routes: 1.25K number of IPv6 multicast groups: 1.125k number of directly-connected IPv6 addresses: 1.5K number of indirect IPv6 unicast routes: 1.25K number of IPv4 policy based routing aces: 0.25K number of IPv4/MAC qos aces: 0.5K number of IPv4/MAC security aces: 0.5K number of IPv6 policy based routing aces: 0.25K number of IPv6 qos aces: 0.625k number of IPv6 security aces: 0.5K