All in all a reasonably productive long weekend. Hope everyone's was similar.
I've managed to get through quite a bit of the Cisco 12.1 IOS QoS configuration guide - 250 pages of .... well, that's tonight's homily. 250 pages of what exactly? Repetition. I wish I had a dollar for every time the docs states that the default bandwidth available to various QoS mechanisms is 75% of the interface bandwidth. Frustration. Not with the quality in general, but with stupid little configuration details and explanations that are obviously in error. For example, if you were to look at the following command, what would you conclude about the PVC? frame-relay map ip 110.1.1.1 16 broadcast probably not the same thing that the documentation states, I'll wager. OK. That's fine. We all know by now that one must view any reference and study materials with a skeptical eye. Surprise. Pleasant surprise Once I started reading, I was pleasantly surprised at how understandable most of this stuff is. Sure there is the bits versus Bytes in the various command lines. But even that is overcome once you get into the mindset. Test Psyching. I can't say it enough - one should never bet on what they think may or may not be testing in the CCIE Lab. But after a while, one cannot help but notice statements like "SBM is not supported currently on Token Ring LANs" and wonder - is this a hint that one might expect to configure this on an ethernet LAN device? Nothing in the 3550 Command Reference or Config Guide regarding RSVP or SBM. But I don't see the most recent documentation on CCO either - just the new image release. Irregardless of the CCIE Lab, I can see where SBM would be of interest in certain client networks. Questions. Lots of questions. The Guide I'm reading is recent. But throughout it talks about using the ToS bits. I may be mistaken - I've read quite a bit of this stuff since Friday, but isn't it the DiffServ field now? Yes it's supposed to be somewhat backwards compatible, but not if you start using all 63 of the possible DiffServ values, or even just Assured Forwarding, which has only 12 possible values. I might be misreading the packet here. DSCP uses bits 0-5 of the old ToS field, with bits 6 and 7 reserved for future use, and looking like they will become the EC bits. This merits further consideration. I'll make a note to carefully examine the QoS configs and commands as I study. It may make no difference whatsoever on the CCIE Lab, but it never hurts to know. Feeling good. Yes, feeling good after a long weekend where I could put in some book time and also spend some time with the family. Takes some of the strain off during these final weeks of preparation. Can't wait to power up the routers and try out some of this stuff. Cool breezes. Still waters. Hot weather, with the hint of autumn. Goodnight, everyone. -- www.chuckslongroad.info like my web site? take the survey! PS - 19 straight! Take that, Mariners, Angels, and Red Sox!!!!! Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=52582&t=52582 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
