Test on Cisco 720xVXR NSE-1

Jason Ackley jason at Ackley.NET
Wed Feb 14 18:11:36 UTC 2001





On Wed, 14 Feb 2001, Michael Kim wrote:

> I have done some performance test on Cisco 720xVXR NSE-1 and the result
> I got in my test do not match with the performance test done by Cisco.
> Is anybody done test on 720xVXR NSE-1?

What particular features on the NSE1 are you trying to use?

After using the NSE1 for some NAT work and still noticing a high CPU
load at ~35Mbits/sec, I dug into it a bit more and discovered a
cisco NAT 'feature'.

If you have a large amount of DNS traffic(src/dst 53) from your 'inside'
to the 'outside' of the NAT box then all the DNS packets are sent to the
main CPU to see if they need to be re-written. Cisco supports rewriting
DNS packets as part of its NAT feature set.

Bug ID CSCdt31360 has been opened to see if Cisco will add a on/off switch
for this particular DNS rewrite feature for platforms with PXF, it is
still Status: N. :(

I did do a simple netperf test (single or multiple TCP connections
running) before putting it in place and did get 100Mbit/sec wire speeds
with very low CPU utilization. Only in the prod environment with DNS
activity do I see a high(er) CPU load. It is not a problem yet, but
I would rather tackle it before it turns into one :)


Hope it helps!!

cheers,

--
jason






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