[ovs-discuss] Port satturation?

Vladimir Nikolić vladimir.nikolic at amis.si
Wed Oct 12 07:27:54 UTC 2011

Yes, you are right.
It never occured to me that arp timeout could be the problem. Probably
because we never had that issue with Cisco switches (ours have 4 hours
default arp timeout) and VMware ESXi internal switch (don't know what is
default arp timeout).
Is it possible the change arp timeout on OVS? Or to enter static mac
addresses into switch mac address table?
Thanks for you help.


On 12. 10. 2011 02:52, Jesse Gross wrote:
> 2011/10/11 Vladimir Nikolić <vladimir.nikolic at amis.si>:
>> The switch should learn syslog server mac address from the arp response,
>> and send traffic only to uplink.
> It learns it and then it times out, just as I said in my first response.
> The problem is that your ARP cache timeout is longer than the switch's
> MAC learning timeout and there are no other transmissions.
> Open vSwitch uses a 60 second MAC table timeout, many physical
> switches use 300 seconds but in both cases it is shorter than the 1200
> seconds that you are using for your ARP cache.  That's why you see
> this behavior.

Vladimir Nikolic | Sistemski administrator / System Administrator

Amis | Trzaska cesta 85 | 2000 Maribor | Slovenija
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