Archive

Category Archives for "Networking"

Ticket #14 – Repubished

I am reposting here Lab 14, which was published on ccieflyer.com. Next ticket, Ticket 15, which will be about multicast will be published on CCIEFlyer.com, then it will be republished here again. ...For more mini labs, have a look at the mini labs page.

Consumer hardware vendors, boxes and versions

Yes, this is actually a rant.
<rant>
I have a Apple Time Capsule which I love and cherish. It's about a year old. No, it isn't the latest model anymore. It claims it is able to talk IPv6... but it doesn't. Sadly, it runs something called version 7.4.2 - that works fine but where IPv6 is broken. To have functioning IPv6 I should have 7.5 or later. That would require me to pay more money for protection to Apple as it seems like it is only available on the Very Latest Time Capsules.
Now, someone explain to me:
  1. what the fuck? over.
  2. why must I buy a new box to get something to work which is supposedly is there already
  3. immediate cessation in software updates upon release of incremental hardware update
  4. if you changed the chipset then how hard can it be to make a conditional instead of drop all future upgrades
  5. fail to communicate what's going to work and what's not
Feel free to google "time capsule 7.4.2 ipv6" for more info.
</rant>
Feels much better now. :-)

IPv6 and the enterprise of tomorrow(ish)

One of the great promises of IPv6 has been to get rid of NAT, no more will IT do RFC1918 and NAPT to single public IP. But how is IPv6 going to accomplish this, what is the magical toggle for it? Let's get disappointed.

Some devices, like Cisco IOS allow you to configure IPv6 prefix as 'macro', so you could tell that macro 'ME' is 2001:db8::/32 and everywhere where you write IPv6 address, you use macro 'ME'instead. So in theory, when your prefix changes, you simply change the macro. So the great renumbering benefit is ability to always get same size network. But of course this was true for IPv4 too, you got the network size you needed. Why isn't this utilized? Because enterprises don't have one Cisco IOS devices, they have plethora of devices from different vendors, firewalls, slb, ips, ids, servers, OSS systems and so forth, you'd still need to go in all of these to change the 'macro', not all devices even have the concept and quite frankly no enterprise of non-trivial size will even know without months of work _where_ and _what_ will need to be changed for renumbering to be successful. I know industry professionals Continue reading

IEEE OUI address (MAC address) allocation

I've recently noticed that it is becoming more and more common to see 'weird' MAC addresses, i.e. MAC addresses which do not start with numbers 00. Previously it was very easy to spot automatically mentally software defects which would cause strange MAC addresses to appear, it has helped me to diagnose several issues in the past. We've now beginning to lose that advantage, as IEEE has started to allocate MAC addresses quite randomly across the address space.

I emailed to IEEE and asked what was the motivation and perceived advantage in doing this change and reply was quite simply 'We changed our allocation methods to prevent vendors using unregistered mac addresses.'. OUI costs 1650USD one time fee, but IEEE appears to be concerned that some vendors choose not to pay it, instead allocate themselves OUI somewhere far in the address space, effectively thinking they are getting free OUI with little to no possibility of overlap. It would be curious to know if this instance who wants to save 1650USD would care about this slightly changed climate, I personally doubt the change while good-willed is completely ineffective and the slight operational benefit serial assignment had is lost. (/me starts Continue reading

Resolving SNMP OID in snmpbulkwalk and tshark

This isn't exactly esoteric science but at least for me it has been too hard and I've rather looked up OIDs manually, which makes little sense in the long run.

NET-SNMP

First of all, you probably want to set system wide version and community, so you never need to type them on snmpbulkwalk
# cat /etc/snmp/snmp.conf defVersion 2c defCommunity supersecret #
Also I prefer to have vendor MIBs for my user only, as I might want to load lot of them, which will give lot of warnings, which other users may not want.
# cat ~/.snmp/snmp.conf mibs +ALL #
Instead of +ALL you could add named MIBs which to load, ~/.snmp/mibs/ directory is searched for users MIBs. You could start by uncompressing ftp://ftp.cisco.com/pub/mibs/v2/v2.tar.gz there. Now you should be able to snmpbulkwalk router by giving just its name, no version, no community and OIDs should be resolved.

WIRESHARK/TSHARK

To me this is more useful than net-snmp, to lab what type of traps router would send and in what situation. For some weird reason wireshark/tshark doesn't honour net-snmp settings, but needs its own settings.
# cat ~/.wireshark/prefefences name_resolve: mtC name_resolve_load_smi_modules: TRUE snmp.display_oid: Continue reading

Ticket #13 – Republished

I am reposting here Lab 13, which was published on ccieflyer.com. Next ticket, Ticket 14, which will be about BGP, OSPF and telnet will be published on CCIEFlyer.com, then it will be republished here again. ...However, its not working, as no router can ping BB1 from it's Lo0.

Cisco Network^WLive! 2011 Las Vegas Conference report, part 2

Part 2... where we take a stab at the food served one gets for 1700 (thereabouts) bucks at conferences.
Breakfast
When: every day 0700-0800 (one hour only)
What's available: cereal + milk, sugary doughnuts, croissants, bottles of juice or soda pop.
Grade: C-. The time could be longer and the stuff available isn't exactly from the food pyramid either. I did this once and the rest of the time paid for hotel breakfast which was excellent.
Lunch
When: 11-13 (or thereabouts)
What's available: different menu every day, lots of choices, veggie, meat, fish, salad, etc. Drinks water, icea tea, lemonade, soda pop
Grade: B+. Certainly isn't a Michelin restaurant experience but seemed nutritious enough, wasn't all greased up, there were plenty of choice each day (beef/fish, fish/chicken, chicken, etc.) and always a veggie choice.
Snacks
When: around 1000, around 1400
What's available: granola bars, sugary coated doughnuts, coffee, tea, water, some fruit, juice, ice cream, ... depending on the day
Grade: B-. Lots of choice. Sometimes the snacks went quite quickly so I didn't get some on a few days when the presentation ended later than planned. Either there were too little snacks to start with or some people stocked Continue reading

Android & Eclipse Troubles

Setting up a new Android Development Environment in Eclipse? Having troubles? Maybe one of these two solutions will help: PROBLEM #1 I recently re-imaged my PC and decided to build my Android Development Environment from scratch. Some recent modifications to my eclipse installation messed it up so I cut my losses and started over again. This time around, I noticed that Eclipse Helios was available for download, and not only that, it was the first version of Eclipse to offer a 64-bit version of the IDE for windows.

Android & Eclipse Troubles

Setting up a new Android Development Environment in Eclipse? Having troubles? Maybe one of these two solutions will help: PROBLEM #1 I recently re-imaged my PC and decided to build my Android Development Environment from scratch. Some recent modifications to my eclipse installation messed it up so I cut my losses and started over again. This time around, I noticed that Eclipse Helios was available for download, and not only that, it was the first version of Eclipse to offer a 64-bit version of the IDE for windows.

Android & Eclipse Troubles

Setting up a new Android Development Environment in Eclipse? Having troubles? Maybe one of these two solutions will help: PROBLEM #1 I recently re-imaged my PC and decided to build my Android Development Environment from scratch. Some recent modifications to my eclipse installation messed it up so I cut my losses and started over again. This time around, I noticed that Eclipse Helios was available for download, and not only that, it was the first version of Eclipse to offer a 64-bit version of the IDE for windows.

Apps of Empowerment

This will be a short one (cough, I’m at work, cough) but I gotta share these links. Downloadsquad.com shares some great links, but these stories in particular give lists of apps that any computer-savvy person must at least be aware of. Before you go googling to download some shoddy software that may or may not do what you want it to, check out these lists first: http://www.downloadsquad.com/2008/09/02/24-killer-portable-apps-for-your-usb-flash-drive/ http://www.downloadsquad.com/2008/10/01/24-great-open-source-apps-for-admins-and-technicians/ http://www.downloadsquad.com/2009/05/18/40-great-open-source-apps-and-games-to-trick-out-your-new-windows/ Again, thanks to Downloadsquad.

Apps of Empowerment

This will be a short one (cough, I’m at work, cough) but I gotta share these links. Downloadsquad.com shares some great links, but these stories in particular give lists of apps that any computer-savvy person must at least be aware of. Before you go googling to download some shoddy software that may or may not do what you want it to, check out these lists first: http://www.downloadsquad.com/2008/09/02/24-killer-portable-apps-for-your-usb-flash-drive/ http://www.downloadsquad.com/2008/10/01/24-great-open-source-apps-for-admins-and-technicians/ http://www.downloadsquad.com/2009/05/18/40-great-open-source-apps-and-games-to-trick-out-your-new-windows/ Again, thanks to Downloadsquad.

IPv6 Deployment Practices and Recommendations

Communications technologies are evolving rapidly. This pace of evolution, while slowed somewhat by economic circumstances, still moves forward at a dramatic pace. This is indicative to the fact that while the ‘bubble’ of the 1990’s is past, society and business as a whole has arrived to the point where communications technologies and their evolution are a requirement for proper and timely interaction with the human environment.

This has profound impact on a number of foundations upon which the premise of these technologies rest. One of the key issues is that of the Internet Protocol, commonly referred to simply as ‘IP’. The current widely accepted version of IP is version 4. The protocol, referred to as IPv4 has served as the foundation to the current Internet since its practical inception in the public arena. As the success of the Internet attests, IPv4 has performed its job well and has provided the evolutionary scope to adapt over the twenty years that has transpired. Like all technologies though IPv4 is reaching the point where further evolution will become difficult and cumbersome if not impossible. As a result, IPv6 was created as a next generation evolution to the IP protocol to address these issues.

Continue reading

Storage as a Service – Clouds of Data

Storage as a Service (SaaS) – How in the world do you?

There is a very good reason why cloud storage has so much hype. It simply makes sense. It has an array of attractive use case models. It has a wide range of potential scope and purpose making it as flexible as the meaning of the bits stored. But most importantly, it has a good business model that has attracted some major names into the market sector.

If you read the blog posts and articles, most will say that Cloud Storage will never be accepted due to the lack of security & accountability. The end result is that many CISO’s & CIO’s have decided that it is just too difficult to prove due diligence for compliance. As a result, they have not widely embraced the cloud model. Now while this is correct, it is not totally true. As a matter of fact most folks are actually using Cloud Storage within their environment. They just don’t equate it as such. This article is intended to provide some insight into the use models of SaaS as well as some of the technical and business considerations that need to be made in Continue reading