RB750 Switch Hardware - Broadcast and Multicast Behavior
Posted: Fri Jun 18, 2010 6:06 pm
I am hoping that somebody has explored the behavior of the Atheros switching hardware that forms the ports of the RB750. Under the default v4.10 configuration, ether1 is set to be a WAN gateway, ether2 is a master port and ether3 to -5 are set as slaves to ether2. The purposes of this is to make the behavior of 2 through 5 be identical for the internal LAN.
Unfortunately, the behavior does not appear to be identical. For example, it seems that broadcast and multicast messages, as well as router advertisements are available on ether2, but their appearance on ether3 -5 are erratic or missing. We haven't done extensive testing on this, but the effect is obvious if one simply substitutes an external switch connected only to ether2 in place of direct connections to the RB750.
Symptoms that led to this investigation include failure of Bonjour advertising and lost router discovery messages (IPV6).
The wiki on this subject is helpful overall ( http://wiki.mikrotik.com/wiki/Manual:Sw ... p_Features ), but it does not suggest a solution. We've confirmed that the configuration of the switch is factory (i.e., software) default, and there are no switch rules.
Under the circumstances, unless this can be explained and documented, the RB750 would appear to be useful as a two port router in the "SOHO" default application.
Unfortunately, the behavior does not appear to be identical. For example, it seems that broadcast and multicast messages, as well as router advertisements are available on ether2, but their appearance on ether3 -5 are erratic or missing. We haven't done extensive testing on this, but the effect is obvious if one simply substitutes an external switch connected only to ether2 in place of direct connections to the RB750.
Symptoms that led to this investigation include failure of Bonjour advertising and lost router discovery messages (IPV6).
The wiki on this subject is helpful overall ( http://wiki.mikrotik.com/wiki/Manual:Sw ... p_Features ), but it does not suggest a solution. We've confirmed that the configuration of the switch is factory (i.e., software) default, and there are no switch rules.
Under the circumstances, unless this can be explained and documented, the RB750 would appear to be useful as a two port router in the "SOHO" default application.