Cisco Says, “No PBR for You, We’re Going with Miller Lite…”

I just found out through working with a TAC Engineer on an issue where our brand spanking new Catalyst 4900M won’t accept the command to place a Policy Based Route map on a vlan interface that PBR will not be supported until an upcoming IOS release, most likely in June.   Ugh.  This is not the first weirdness we’ve had with our 4900M’s.  The first was with one of the 4900M’s we have deployed in our new datacenter core.  This switch displayed some weird behavior when we were troubleshooting what appeared to be an issue with a fiber uplink in a twingig module we had plugged into one of the ten-gigabit ports.  We shuffled around some known-good GBICs in these twingigs and next thing we knew, the ports had error-disabled due a Cisco “feature” that keeps you from using illegal hardware, giving us an error of “Unapproved GBIC” in the output of a show interface status.  A reboot got us our ports back, but to this day one of the ports still shows that error even though it works and TAC hasn’t been able to help us be rid of it.  Apparently, on most of the higher-end switches, the database that keeps track of GBIC serial numbers times out entries after a certain period so that you can reuse a GBIC from one module in the switch to another without much trouble…in the 4900M’s they have yet to perfect this.

Don’t get me wrong, the 4900M’s are definitely good hardware and allow you to double your port density in modules you don’t want to use TenGigabit in by using the twingig modules that give you 2 1Gig ports instead, while still giving you the option down the road of using half as many tengigabit ports.  That can be a very handy feature when combined with the port density they already have and is the reason we have 4 of them in the core of our datacenter.  I just wish Cisco had worked out a few more kinks before releasing them.

But enough complaining…it’s good to have job security in these uncertain times!  My BCMSN studies are coming along well and I’m up to chapter 8 in the self-study guide.  That doesn’t sound like much, but the self-study guide’s chapters are all pretty meaty.  I also managed to watch 4 hours straight of CBT Nuggets this weekend before needing a nap.  My lab setup is almost finished and I hope to get it accessible from my desk as soon as there is a lull in the datacenter cabling.  Until then, I hope to keep pushing on my reading.  I’ve already really enjoyed some of the information on MST, which allows you to combine multiple instances of spanning tree into one instance, saving resources and allowing you to more easily use redundant links for load-balancing instead of just leaving them in blocking.  I’ve also really enjoyed the section on etherchannel, particularly doing more sophisticated load-balancing over multiple etherchannel links.

Back to BCMSN!

Well, I have survived both the first part of the data center move as well as the first game of the softball season, so I am ready for a new exam to study for.  I am going next for the BCMSN and I received my copy of the BCMSN self-study guide from Cisco Press.  It’s definitely the heftiest of my Cisco books right now, even outweighing Routing TCP/IP vol 1.  I’ve just started digging into the first chapter and already, from judging the table of contents, I’m wishing I’d read this one about 6 months ago!  There is an entire chapter on dhcp snooping, something which was giving me fits at one of our autonomous wireless sites a few months ago.  It would have been easier then if I’d been familiar with the concept of dhcp snooping.  Oh well!  I always feel like I’m 1 exam behind what I’m doing at work.

This ought to be a great exam for me to study for right now.  We don’t have many routers in our enterprise, but mostly rely on big layer 3 switches.  We use HSRP heavily and have rapid-spanning tree implemented.  These are all things I’ve worked with in practice but never had the time to dig deeper into how they actually work.  My studies for the CCNA-Wireless ought to also make the wireless portion of this exam a little easier to handle and I’m thinking that having already taken the ONT will help with the QoS portion.  There really is a good amount of overlap in some sections of these exams, which might be why everyone thinks their last 1 or 2 CCNP exams are the easiest of the bunch.

This weekend is all about resting up and relaxing.  I’m planning to do some reading, some grilling, and maybe playing catch with the family, but nothing hardcore.  The past 2 weeks have involved a lot of physical work in the datacenter installing switches, running cables, and labeling the heck out of everything.  The payoff is a brand new datacenter with a 10 gig backbone which hopefully will lead to fewer calls of “application slowness” when I’m on call!