The Call of Cisco, Part 1
A Voyage to the Edge of Madness
(With sincere apologies to H. P. Lovecraft.)
It was in the depths of drear winter when I first sought to acquire that dark magic known only through fragments of ancient, incomprehensible legend as Veepee Enn. It is a dread name, and initiates speak of the thousandfold paths to attainment of its secrets, hinting often at some deep unknowable hierarchy through chains of characters concocted to discourage all but the most determined seeker. Lines of impenetrable seeming-nonsense serve to keep the novice from approaching the level of those who control the communications of a galaxy of possibilities, and unless the elect can decipher the meanings of the names of entities such as “The eight-hundred-and-seventy-seventh W, Gee Eee, K the Ninth,” he should abandon any wish he may have to attain true greatness.
Intrigued by the promise of the power held in the devices of the most mighty of those who speak with fire, the shadowy high priests and worshippers of the amorphous entity identified only by the cryptic designation of CISCOSYSTEMSINC, I slaved for many a day and night to acquire the knowledge and the mechanisms necessary, in order to learn the rites that I might one day master Veepee Enn. Little suspecting the horror that awaited me, I collected many strange and curious artifacts and tomes of deep lore, to be well prepared for my quest to speak with the power of lightning across the great gulfs of night. At long last, after many a false turn and mistaken track, I determined that the stars were correctly aligned and that I could begin the long toil known to those few who have survived as “Configuring a bloody Cisco router”.
I shall not speak of the appalling fate awaiting anyone foolish enough to attempt the dark rites of configuration whilst using a flaky ADSL connection. Suffice to say I escaped with little more than sorry shreds of my former sanity, and the howling terrors I encountered during that ordeal will haunt me unto the grave. Weeks later, after a period of recovery, and much weakened but undaunted, I returned to my labours and sank once more into my great work. I sought out those arcane works of O’Rlyeh treating of the deepest and most mysterious incantations, long forgotten by all but the most unfortunate. Slowly I progressed, and as the days passed unheeded my power grew ever greater, until I felt sure that I would soon be able to attain my final object.
The first stage of my ultimate task would be to create a beacon, that those who sought to communicate with me across the abyss might find me more easily, and accordingly I arranged with the appointed authorities a name by which I might be identified to all the universe. Thus prepared, I approached the altar humbly and made the prescribed obeisances, but to no avail: dynamic DNS updates set up via the SDM on a Cisco 877w router don’t actually work. There was nothing else for it; I must venture into the darksome reaches of what is ominously named “The Terminal”.
The oracle spake thus:
Authorized access only!
Disconnect IMMEDIATELY if you are not an authorized user!
Fortunately I knew the correct response and thereby avoided the horrors saved for those unable to commune with the primal forces of IOS. I proceeded carefully through the rite, describing in sigils of white fire the ancient, obscure words of command.
cisco877w>enable
cisco877w#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
cisco877w(config)#ip ddns update method DynDNS
cisco877w(DDNS-update-method)#http
cisco877w(DDNS-HTTP)#add http://username:password@members.dyndns.org/nic/update?hostname=<h>*
cisco877w(DDNS-HTTP)#interval maximum 28 0 0 0
cisco877w(DDNS-update-method)#exit
cisco877w(config)#interface Dialer0
cisco877w(config-if)#ip ddns update hostname myhostname.dyndns.org
cisco877w(config-if)#ip ddns update DynDNS host members.dyndns.org
cisco877w(config-if)#exit
cisco877w(config)#exit
All that remained was to permit access from without through the eightieth portal for the members of the organisation of Dyndns:
access-list [NNN] permit tcp host [IP of members.dyndns.org] eq www any
As the great Networknomicon of O’Rlyeh advises, even the wisest of initiates would wish to carry out this last step by uploading text files at the very least, in order to avoid ACL-retyping induced brain damage. Accordingly, I once again approached the simple, Javanese altar and made the required offerings. I know not what small detail I omitted from my ritual; perhaps the black cockerel whose blood outpoured to appease the ancient ones was insufficiently sable; perchance a cloud passed in front of the loathsome, blood-red moon which loomed o’er the tormented globe like a savage, accusing eye; maybe I typed something wrong, whatever, the router CPU was pegged at 100% and nothing was working any more. You could almost see the tentacles. Sighing, I walked over to the seat of the power I sought to master, a squat, idolatrous box with winking, green eyes and demonic horns, and resorted to the most ancient and honoured spell of them all: I tried turning it off and on again.
You of those fortunate masses, the multitude who don’t ever have to deal with Cisco routers, will not be aware that the reset of such apparatus results in the reversion of all the carefully crafted work of the knowledge-seeker to nothing, back to the inchoate, base state known to some as ‘the last saved configuration’. All my work of the last few hours was now come to naught, so with heavy heart I began my labours afresh. Hours later I had once more attained the same point, and with trepidation I again lowered and raised the conduit named “Dialer0″ and watched the debug output anxiously. This time, to my great joy, the incantations worked, energy cascaded across the void directed according to my exact command, and in a distant city under the stars a database field was updated precisely according to my wishes. Exhausted I fell back in my chair and, after a period of recovery, began to plot the next coördinates on the course towards my final aim, via the mysterious Labyrinth of Ipp-Secc.
To be continued, provided I don’t lose my mind whilst trying to comprehend internet key exchange.
* You need to type Ctrl-V before typing ? on line 6 up there, or IOS will spit out gibberish in an attempt to provide contextual help. This behaviour is by design, insane, crazed design from the lunatic souls imprisoned in Cisco’s massive subterranean developer dungeons. For a less sarcastic and more useful guide to getting your damned Cisco router to actually obey the rules of a more-or-less sane universe, try this useful post on DDNS updates.