Hello.
I am trying to understand the exact meaning of
“Limit broadcasts”
“Limit unknown unicasts”
“Limit unknown multicasts”
in Switch - Port properties (RB4011iGS+), but can’t find it in online manual.
I would like to know if word “limit” means some threshold or block entirely.
If it is threshold, then where do I set that.
Thanks a lot in advance.
unknown-multicast-flood (yes | no; Default: yes)
When enabled, bridge floods unknown multicast traffic to all bridge egress ports. When disabled, drops unknown multicast traffic on egress ports. Multicast addresses that are in /interface bridge mdb are considered as learned multicasts and therefore will not be flooded to all ports. Without IGMP Snooping all multicast traffic will be dropped on egress ports. Has effect only on an egress port. This option does not limit traffic flood to the CPU. Note that local multicast addresses (224.0.0.0/24) are not flooded when unknown-multicast-flood is disabled, as a result some protocols that rely on local multicast addresses might not work properly, such protocols are RIPv2m OSPF, mDNS, VRRP and others. Some protocols do send a IGMP join request and therefore are compatible with IGMP Snooping, some OSPF implementations are compatible with RFC1584, RouterOS OSPF implementation is not compatible with IGMP Snooping. This property should only be used when igmp-snooping is set to yes.
unknown-unicast-flood (yes | no; Default: yes)
When enabled, bridge floods unknown unicast traffic to all bridge egress ports. When disabled, drops unknown unicast traffic on egress ports. If a MAC address is not learned in /interface bridge host, then the traffic is considered as unknown unicast traffic and will be flooded to all ports. MAC address is learnt as soon as a packet on a bridge port is received, then the source MAC address is added to the bridge host table. Since it is required for the bridge to receive at least one packet on the bridge port to learn the MAC address, it is recommended to use static bridge host entries to avoid packets being dropped until the MAC address has been learnt. Has effect only on an egress port. This option does not limit traffic flood to the CPU.
thank you very much for quick comprehensive response
It says default for broadcast-flood is yes.
I have “Limit broadcasts” checked on all ten ports of RB4011 and I am sure I did not set it like that.
How that that checkmark got set to non-default value?
Thanks a lot in advance.
Hi,
in ROS 6.49.6 I turned on IGMP snooping on the bridge. The bridge has no IP. The egress ports in the bridge all have unknown-multicast-flood=no (except for the ingress-port), unknown-unicast-flood=no, unknown-broadcast-flood=no, but all multicast traffic goes from the multicast source to all ports, although only one desired IGMP group is learned on an egress port in the bridge mdb.
Why? The traffic should only be forwarded to the learned port of the learned mdb Group…
christian