[c-nsp] WARNING: Netflow Hardware assisted NAT not supported on 65xx on the same interface even with Sup2T
Hi all, I leave it here JFTR, to prevent someone else to make the same error as I did with NAT, Netflow and Sup2T (just as Matthew Huff did before me with Sup720). According to Cisco because of CSCud36118, enabling NAT (ip nat outside) and Flexible NetFlow (ip flow monitor MonitorFlow input) on the same interface force NAT traffic to be software switched even with Sup2T. Although TAC states that this is software limitation, I've been told that there it no plan to support this feature combination in hardware. HTH -Original Message- From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Matthew Huff Sent: Friday, August 26, 2011 10:26 AM To: 'cisco-nsp at puck.nether.net' Subject: [c-nsp] WARNING: Netflow Data Export Hardware assisted NAT not supported on 76xx/65xx on the same interface Last winter we purchased a pair of 7606 routers to use out at the NYSE colo facility. We connect via a 1gb fiber to the SFTI LCN for market data and FIX traffic. We fully expected to be able to use hardware assisted NAT and NDE to monitor the traffic. The netflow output we get is random, sporadic and very incomplete. After dealing with our Sales team and TAC, we have finally got them to admit that it doesn't work when NAT and NDE are configured on the same interface. Nowhere in the Cisco marketing literature, Cisco Documentation, or even Cisco bug lists does it mention this. There are some caveats listed regarding NDE and NAT (flow mask conflicts, and fragments), but even given that, the caveats imply that it will work if the caveats don't apply or the flowmask conflicts are resolved. Also, there are no warnings when configuring it. The feature manager shows no errors or conflicts, etc... At every step, in my opinion, cisco has been reluctant to admit that it doesn't work. Only when confronted with the evidence, they did finally admit it. Had we known of this limitation, we would have purchased different hardware including possibly another vendor's solution. I'm looking at using SPAN to replicate the data and send it to a linux box to then create netflow data exports, however, given the nature of the data (high bandwidth and microburst), I'm not sure that the Linux box will work accurately. I assumed the PFC would be doing the exports in hardware giving us the most accurate realtime look at the market data. Evidently I was wrong. I'm sending this so that no one else will make the same mistake we did as well as being in the nsp archives. Matthew Huff | 1 Manhattanville Rd Director of Operations | Purchase, NY 10577 OTA Management LLC | Phone: 914-460-4039 aim: matthewbhuff| Fax: 914-460-4139 ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] WARNING: Netflow Hardware assisted NAT not supported on 65xx on the same interface even with Sup2T
FYI, At least cisco went back end and added caveats to the documentation about this limitation. Since I had combed through all the documentation beforehand, had the caveat been there, it would have been likely we would have purchased a different set of hardware. Matthew Huff | 1 Manhattanville Rd Director of Operations | Purchase, NY 10577 OTA Management LLC | Phone: 914-460-4039 -Original Message- From: cisco-nsp [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of oldnick Sent: Friday, October 11, 2013 2:46 AM To: cisco-nsp@puck.nether.net Subject: [c-nsp] WARNING: Netflow Hardware assisted NAT not supported on 65xx on the same interface even with Sup2T Hi all, I leave it here JFTR, to prevent someone else to make the same error as I did with NAT, Netflow and Sup2T (just as Matthew Huff did before me with Sup720). According to Cisco because of CSCud36118, enabling NAT (ip nat outside) and Flexible NetFlow (ip flow monitor MonitorFlow input) on the same interface force NAT traffic to be software switched even with Sup2T. Although TAC states that this is software limitation, I've been told that there it no plan to support this feature combination in hardware. HTH -Original Message- From: cisco-nsp-bounces at puck.nether.net [mailto:cisco-nsp-bounces at puck.nether.net] On Behalf Of Matthew Huff Sent: Friday, August 26, 2011 10:26 AM To: 'cisco-nsp at puck.nether.net' Subject: [c-nsp] WARNING: Netflow Data Export Hardware assisted NAT not supported on 76xx/65xx on the same interface Last winter we purchased a pair of 7606 routers to use out at the NYSE colo facility. We connect via a 1gb fiber to the SFTI LCN for market data and FIX traffic. We fully expected to be able to use hardware assisted NAT and NDE to monitor the traffic. The netflow output we get is random, sporadic and very incomplete. After dealing with our Sales team and TAC, we have finally got them to admit that it doesn't work when NAT and NDE are configured on the same interface. Nowhere in the Cisco marketing literature, Cisco Documentation, or even Cisco bug lists does it mention this. There are some caveats listed regarding NDE and NAT (flow mask conflicts, and fragments), but even given that, the caveats imply that it will work if the caveats don't apply or the flowmask conflicts are resolved. Also, there are no warnings when configuring it. The feature manager shows no errors or conflicts, etc... At every step, in my opinion, cisco has been reluctant to admit that it doesn't work. Only when confronted with the evidence, they did finally admit it. Had we known of this limitation, we would have purchased different hardware including possibly another vendor's solution. I'm looking at using SPAN to replicate the data and send it to a linux box to then create netflow data exports, however, given the nature of the data (high bandwidth and microburst), I'm not sure that the Linux box will work accurately. I assumed the PFC would be doing the exports in hardware giving us the most accurate realtime look at the market data. Evidently I was wrong. I'm sending this so that no one else will make the same mistake we did as well as being in the nsp archives. Matthew Huff | 1 Manhattanville Rd Director of Operations | Purchase, NY 10577 OTA Management LLC | Phone: 914-460-4039 aim: matthewbhuff| Fax: 914-460-4139 ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] WARNING: Netflow Hardware assisted NAT not supported on 65xx on the same interface even with Sup2T
On 11/10/13 14:11, Matthew Huff wrote: FYI, At least cisco went back end and added caveats to the documentation about this limitation. Since I had combed through all the documentation beforehand, had the caveat been there, it would have been likely we would have purchased a different set of hardware. Have they pulled that great Cisco trick of updating the docs but not updating the last edited timestamp, fooling you into thinking it's always been there? ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
Re: [c-nsp] WARNING: Netflow Hardware assisted NAT not supported on 65xx on the same interface even with Sup2T
No idea. I didn't check at the time. Since the document is updated regularly, I doubt they needed any subterfuge. The last modified date is now July 30th, 2013. It's in Configuring NetFlow and NDE in the Cisco 7600 Series Router Software Configuration Guide Cisco IOS Release 15S documentation. This is what was added: Note NDE and NAT configuration on the same interface is not supported. NDE requires flows to age out periodicaly for it to export its statistics. NAT installs hardware shortcuts that do not age. Hence, NDE for NAT'd flows does not work correctly. Matthew Huff | 1 Manhattanville Rd Director of Operations | Purchase, NY 10577 OTA Management LLC | Phone: 914-460-4039 -Original Message- From: cisco-nsp [mailto:cisco-nsp-boun...@puck.nether.net] On Behalf Of Phil Mayers Sent: Friday, October 11, 2013 11:24 AM To: cisco-nsp@puck.nether.net Subject: Re: [c-nsp] WARNING: Netflow Hardware assisted NAT not supported on 65xx on the same interface even with Sup2T On 11/10/13 14:11, Matthew Huff wrote: FYI, At least cisco went back end and added caveats to the documentation about this limitation. Since I had combed through all the documentation beforehand, had the caveat been there, it would have been likely we would have purchased a different set of hardware. Have they pulled that great Cisco trick of updating the docs but not updating the last edited timestamp, fooling you into thinking it's always been there? ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ ___ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/