North American Network Operators Group

Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical

SUMMARY: bw usage?

  • From: David M. Ramsey
  • Date: Fri Jul 28 09:50:42 2000

Thanks to everyone who shared thoughts, ideas and experience 
regarding monitoring bandwidth usage on Ethernet switch ports
without including broadcast traffic.

EVERYONE tends to agree that a separate VLAN for each co-located
customer is the only professional way to do things "right".  

I agree, and plan to move in that direction, fast.  Then I won't 
have to worry about broadcast traffic, either!  

Other recommended solutions included:

   - MRTG 
     This is great (I use it elsewhere) but it doesn't directly 
     address the issue I have of *not* including broadcast traffic

   - Cisco 6500 switches apparently support "Private VLANS", which
     don't burn up IP addresses.  Sounds cool, wish I had a 6500 ;-)

   - AUI port -- several people pointed out that an unused AUI port
     on a switch will log broadcast traffic and no other; I can subtract
     that from traffic monitored on all other ports.  Some people
     said that an unused VLAN1 has same behavior.

   - dumb hub -- by plugging in a dumb, passive Ethernet hub with 
     nothing connected, it will receive broadcast traffic.  I can 
     then subtract that ports byte counters from others. 

   - Cisco NetFlow / cflowd ( http://www.caida.org/tools/measurement/cflowd/ )
     Seems very thorough, overkill for me right now.

   - RMON counting of unicast-Octets only

   - Extracting SNMP # multicast/broadcast packets, using average packet 
     size and subtracting product from total byte count
     
   - HPOV + SNMPv2
   
Regards to all, --dmr

David Ramsey
Charlotte, NC