I agree as far as the traffic source. However I think queue- thresholding is relevant only for incoming traffic. So what we are talking about is what happens between the control-plane and the tx- ring. Packets generated by the cp for IGP traffic has internal tag of pak_priority. This should go into a special queue and has the most direct access to the tx-ring.
On May 14, 2010, at 2:52 PM, Adrian Brayton <[email protected]> wrote: > I think the direction that you want to head in is "Control Plane"... > > > On May 14, 2010, at 12:16 PM, Paul Stewart wrote: > >> Maybe priority queue is a misuse of the term. But my understanding >> is that in IOS, there is a special queue for packets tagged >> internally as pak_priority (all routing protocols except bgp). This >> shields them from going to class-default and effectively gives them >> access to the 100% - max reservable bandwidth. Therefore they get >> priority to the tx-ring(but not necessarily cassified in the >> priority queue I suppose?). I'm not sure how different the ASA is >> in this regard. >> >> >> >> On May 14, 2010, at 11:41 AM, Brandon Carroll >> <[email protected]> wrote: >> >>> I'd have to revisit this, because it's been some time since I've >>> done anything with it, but I recall something from the old QOS >>> class about the max-reservable bandwidth is defaulted to 75% of >>> the link bandwidth so that routing protocols and other traffic can >>> have a little breathing room. Like I said, I'll have to revisit >>> this, but I think this may be the case. I don't think routing >>> protocol traffic actually uses the "priority" queue on Cisco >>> routers, unless you classify the traffic and put it there. >>> >>> Sorry if I'm off base here, just thinking out loud. >>> >>> >>> >>> Regards, >>> >>> Brandon Carroll - CCIE #23837 >>> Senior Technical Instructor - IPexpert >>> Mailto: [email protected] >>> Telephone: +1.810.326.1444 >>> Live Assistance, Please visit: www.ipexpert.com/chat >>> eFax: +1.810.454.0130 >>> >>> IPexpert is a premier provider of Self-Study Workbooks, Video on >>> Demand, Audio Tools, Online Hardware Rental and Classroom Training >>> for the Cisco CCIE (R&S, Voice, Security & Service Provider) >>> certification(s) with training locations throughout the United >>> States, Europe, South Asia and Australia. Be sure to visit our >>> online communities at www.ipexpert.com/communities and our public >>> website at www.ipexpert.com >>> >>> Platinum Solutions Group (PSG) provides high-end consulting >>> services with a primary emphasis on Cisco's Data Center Solutions, >>> Service Provider Solutions, Unified Communications and Security- >>> enabled infrastructures. Be sure to visit www.platinumsolutionsgroup.com >>> . >>> >>> >>> >>> On May 14, 2010, at 5:37 PM, Paul Stewart wrote: >>> >>>> I think this is not just an ASA thing. It seems that routing >>>> protocol >>>> traffic is always handled by the priority queue on a router as >>>> well. >>>> >>>> >>>> >>>> On May 14, 2010, at 3:06 AM, Anantha Subramanian Natarajan >>>> <[email protected] >>>>> wrote: >>>> >>>>> Hi All, >>>>> >>>>> Was reading through Chapter 11(QOS) on the Cisco ASA:All-in-One >>>>> Firewall,IPS,Anti-X, and VPN Adaptive security appliance" book and >>>>> inferring >>>>> the below sentence from that >>>>> >>>>> "Certain critical keep-alive packets such as EIGRP hello packets >>>>> are >>>>> never >>>>> dropped even if they are not prioritized in the shaped traffic" >>>>> >>>>> Have a question on that, >>>>> >>>>> 1) Is all protocols hello packets treated that way in Cisco ASA >>>>> and >>>>> if so, >>>>> how Cisco ASA keeps track of that to have this exception. >>>>> >>>>> Thanks for the help >>>>> >>>>> Regards >>>>> Anantha Subramanian Natarajan >>>>> >>>> _______________________________________________ >>>> For more information regarding industry leading CCIE Lab >>>> training, please visit www.ipexpert.com >> > _______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
