packetqueue.net

Musings on computer stuff, and things... and other stuff.

Cisco

Cisco Live!

Read­ing Time: 1 minute

I just want­ed to drop a quick note here to let every­one know that I plan on blog­ging a lit­tle more fre­quent­ly this week, as I’ll be in Las Vegas for the annu­al North Amer­i­can Cis­co con­fer­ence: Cis­co Networkers/Live. I can’t promise I’ll be in my room slav­ing over long, elab­o­rate break­downs of technology–maybe an in depth review of whiskey selec­tions by bar–but I will try to post some pic­tures and infor­ma­tion about what I’m see­ing and hear­ing dur­ing the show. In years where I haven’t been able to attend the show, I always liked see­ing and hear­ing from folks who did. Now it’s my turn to give back some­thing, so watch this space…

Oh, and keep up with real-time infor­ma­tion on twit­ter where I hide behind the han­dle @someclown, or G+ where I can be found at: http://gplus.to/someclown.

Share

Uncategorized

Nostalgia

Read­ing Time: 1 minute

So, nos­tal­gia about com­put­ers and the “good ole’ days” gets strong with me when­ev­er I turn on my old Apple II, or pull out any old mag­a­zines from the ear­ly 80’s or 90’s. My wife laughs at me because I still get goose­bumps and a light in my eye describ­ing how I felt when I first saw the Apple IIgs or the Ami­ga 1000, and how bad I want­ed them. It takes me back to when com­put­ers were fun, mag­i­cal, and rep­re­sent­ed a brave new world to my young mind (with apolo­gies to Aldous Hux­ley).

So it is with great excite­ment that I now have in my pos­ses­sion a book on that ear­ly time, writ­ten about one of the pio­neer­ing com­pa­nies sub­ject to more his­tor­i­cal revi­sion­ism than most peo­ple real­ize.

“Com­modore, a com­pa­ny on the edge” by Bri­an Bag­nall is an in-depth, inter­est­ing, and more his­tor­i­cal­ly accu­rate por­tray­al of the ear­ly his­to­ry of micro­com­put­ers in gen­er­al, but Com­modore in par­tic­u­lar, than many I’ve read. Most ear­ly his­to­ries are writ­ten by revi­sion­ist authors like Robert Cringe­ly and tend to dra­mat­i­cal­ly over­state Apple and IBM’s con­tri­bu­tions at the expense of Com­modore and Atari, among oth­ers.

I’ll post a com­plete review when I’m done with the book, but just what I’ve read so far has me pin­ing for sim­pler times. Before I knew acronyms like CCIE, OSPF, NX-OS and had a glob­al enter­prise net­work to tame, I had my Apple II, the Com­modore 64, the Ami­ga 1000 and the Atari ST. They say you can’t go back again, but I’m try­ing.

Share

Cisco

IPv6 Half-truths

Read­ing Time: 2 min­utes

This post will be a short one, and most­ly just comes from a dis­cus­sion I had the oth­er day with anoth­er engi­neer.  It turns out that even among peo­ple who are com­fort­able with IPv6, and maybe even have expe­ri­ence deploy­ing it, a lot of mis­in­for­ma­tion still per­sists.  Hope­ful­ly I can cor­rect a cou­ple of those today.  I also tossed in a hot-pota­to at the end just to see how many folks get hopped up.  Dis­cus­sion is wel­come, and in addi­tion to com­ments here I can be found on twit­ter hid­ing behind the han­dle: @someclown.

You must turn on IPv6 by using the IPv6 uni­cast-rout­ing com­mand.

Not true.  This is one of the more per­sis­tent, yet wild­ly incor­rect, pieces of infor­ma­tion regard­ing IPv6.  I have even seen many train­ing cen­ters and instruc­tors at the CCIE lev­el get this one wrong and it falls into the cat­e­go­ry of atten­tion to detail.  What this com­mand actu­al­ly does is enable uni­cast rout­ing for IPv6, just as it says.  To actu­al­ly enable IPv6 you sim­ply need to go to any inter­face and use the ipv6 enable com­mand.  And yes, you can enable IPv6 on the inter­face with­out enabling uni­cast rout­ing.  Of course, it would be help­ful to have an address on the inter­face as well.

Yes, but if you don’t turn on uni­cast rout­ing you can’t route IPv6 traf­fic.

Not strict­ly speak­ing true.  You can still set up a default route for IPv6 traf­fic and get it off of your sys­tem.  To the extent that you want to argue whether or not this is actu­al­ly rout­ing is fine, but you can move IPv6 traf­fic off of your local device using a default route, and nev­er have enabled rout­ing for IPv6.

Using a /127 address on point-to-point links is wrong, wrong, wrong.

This is an inter­est­ing one, and usu­al­ly sparks a fair amount of debate.  Up until very recent­ly, the rec­om­men­da­tion across the board (RFC 4291) was to use /64 address­es even on point-to-point links, osten­si­bly because the IPv6 space is so big any­how, and because sev­er­al pro­to­cols will break (notably sub­net-router any­cast, spec­i­fied in RFC 3627).  While I’m not dis­put­ing that this is what the cur­rent best-prac­tices reflect, I will say that RFC 6164 which has a sta­tus of Pro­posed Stan­dard makes a fair­ly com­pelling case for using /127 on point-to-point links.  I’m sure this won’t be resolved any­time soon, stan­dards or no, but I would say that if you have a com­pelling rea­son for using /127 and know what you’re doing it for, go for it.  Just be aware that stan­dards can change, and you don’t want to leave a steam­ing pile for the poor per­son who has to fol­low you.

Share

Cisco

Home CCIE Study Lab

Read­ing Time: 2 min­utes
So, a lot of peo­ple who are work­ing towards their CCIE cer­ti­fi­ca­tions end up build­ing home labs for study­ing.  The rea­sons are many and var­ied, but mine boiled down to two pri­ma­ry ones:

 

(1) My study hours don’t always match well with what slots the online rack ven­dors have avail­able.

(2) I just like phys­i­cal equip­ment and the flex­i­bil­i­ty it pro­vides in both study­ing and in research.

Also, I just wan­na.

With that said, one of the next things peo­ple want to know is what gear it is that I have, and how do I have it con­fig­ured.  There­fore, with the recent post­ing fre­quen­cy here severe­ly lack­ing, writ­ing about my lab is a nice way to get some­thing fresh on the blog and hope­ful­ly it pro­vides some­thing use­ful to some­one out there.  I’m going to break this down into two gen­er­al cat­e­gories: equip­ment that I have pure­ly for my Cis­co CCIE lab, and oth­er equip­ment that I have either for my home net­work or for ran­dom rea­sons.

Ran­dom Non-Lab Spe­cif­ic Equip­ment List:

  1. WS-2950T-24 switch
  2. Two 1142N access points
  3. Wire­less Con­troller Mod­ule (NME-AIR-WLC6-K9) which is pret­ty fun, but breaks bon­jour and so is the bane of my exis­tence (see pre­vi­ous post here.)
  4. ASA 5505 with IPS mod­ule, run­ning bot-net fil­ter and some oth­er things.  This is also the main gate­way for the home net­work, con­nect­ing up to the cable modem.  It’s also the IPsec end­point for my always-on con­nec­tion to the office and seg­ments my home net­work, lab net­work, work net­work, etc.
  5. Com­cast Cable Modem, made by Motorol­la
  6. Ran­dom doohick­ey for my “Whole-Home DVR” with DirecTV
  7. Sun Sun­Fire v240 Serv­er with StorEdge 3300 stor­age array

Non-plugged in Equip­ment

  1. Sun Enter­prise 3500
  2. Two Cis­co 3550 switch­es
  3. Two PIX 501

Com­put­er stor­age:

  1. Sea­gate 750GB exter­nal dri­ve (USB)
  2. Iomega 1TB exter­nal (eSA­TA)
  3. Drobo S with 5 2TB dri­ves for 10TB raw (eSA­TA)

Cis­co Lab Equip­ment:

  1. Four 3560‑X switch­es, with four-gig uplink mod­ules (might still get the 10 at some point), ful­ly licensed with IPSer­vices and run­ning 12.2(53) SE2.
  2. Eight 2801 routers, all run­ning 12.4(22)T5 Advanced Enter­prise, and all with at least one Wic-2T smart ser­i­al card which pro­vides two smart ser­i­al con­nec­tions.  Four of the 2801 have two Wic-2T cards, and a cou­ple oth­ers have a mix­ture of 1‑Wic-DSU-T1 cards, FXO cards, and FXS cards (most­ly left­overs and hand-me downs, but there are some inter­est­ing pos­si­bil­i­ties.)
  3. One 2811 run­ning the same IOS as the 2801 routers, used as a back­bone router for inject­ing routes and some oth­er misc. stuff.
  4. One 2621 run­ning some­thing-or-oth­er and act­ing as anoth­er back­bone router.
  5. One 3845 run­ning the same Advanced Enter­prise as the oth­ers.  This has five Wic-2T cards and acts as the frame switch. It also has an HWIC-16A card and does reverse-tel­net to every­thing else (ter­mi­nal serv­er).  It also hous­es some ran­dom stuff includ­ing the wire­less con­troller men­tioned above.

All of this is cabled and wired almost iden­ti­cal­ly to the CCBoot­Camp lab topol­o­gy.  This is because I have all of their work­books and want­ed to be able to study with my own equip­ment.  A cou­ple of the details are dif­fer­ent, most­ly around inter­face num­bers and the specifics of the back­bone routers and such.  Also, the switch­es I have are way overkill but sat­is­fy the lab require­ments.  Giv­en the actu­al topol­o­gy from just about any main­stream train­ing provider, I can copy it with the equip­ment I have, and that’s exact­ly what I want­ed to be able to do.  As always, con­tact me here or on twit­ter with ques­tions and com­ments.

Pic­tures of the lab and sun­dries are includ­ed below.

Share

Cisco

Cisco Live 11 Schedule

Read­ing Time: 1 minute

Every­one has been post­ing their sched­ules for Cis­co Live to Twit­ter, Face­book and wher­ev­er else, so I thought I’d bet­ter jump in with the cool kids and pub­lish mine as well.  I can’t guar­an­tee this won’t change, but for now it stands as my best guess and cur­rent planned sched­ule.

Share