Controller Based WLANs

Are the VRRP advertisements (Multicast dest.ip=224.0.0.18, IP protocol=112) sent out to the air?

Environment Information  :  

 

Any Aruba Controller
Any Access Point
Any Aruba OS 

 

 

Symptoms  :  If we want clients to learn ARP from VRRP advertisements, we don't see the VRRP advertisements sent to the clients in the same VLAN as the VR IP. 

 

Cause  :  Sending out the VRRP advertisement over the air just for another VRRP member to join, would create a lot of unnecessary traffic for the wireless clients and hence reduces the air bandwidth on all APs. 

 

Resolution  :  Although destined to a Multicast IP address, the VRRP Advertisement is only for the VRRP member to take part.  Sending out the VRRP advertisement over the air just for another VRRP member to join, would create a lot of unnecessary traffic for the wireless clients and hence reduces the air bandwidth on all APs.  Morever clients should not be learning the arp via VRRP advertisement.  Hence Aruba Controller wil ensure VRRP Advertisement packets will not be sent out to the air.  This is not to be confused with ICMP echo frames, we may see the frames sent to the air when we test 'ping 224.0.0.18' on a wired client connected to the wireless vlan.   VRRP advertisement will not be sent to the air even though all BC/MC filters are disabled (bcmc-optimizaiton, broadcast-filter all/arp). 

 

 

Answer  :  Although destined to a Multicast IP address, the VRRP Advertisement is only for the VRRP member to take part.  Sending out the VRRP advertisement over the air just for another VRRP member to join, would create a lot of unnecessary traffic for the wireless clients and hence reduces the air bandwidth on all APs.  Morever clients should not be learning the arp via VRRP advertisement.  Hence Aruba Controller wil ensure VRRP Advertisement packets will not be sent out to the air.  This is not to be confused with ICMP echo frames, we may see the frames sent to the air when we test 'ping 224.0.0.18' on a wired client connected to the wireless vlan.   VRRP advertisement will not be sent to the air even though all BC/MC filters are disabled (bcmc-optimizaiton, broadcast-filter all/arp).

   

 

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Last update:
‎07-10-2014 05:47 PM
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