Simple network management protocol, SNMP - part 2

Without MIB, SNMP would be worthless. Management information base or MIB is a virtual database used for managing entities in a communications network. Objects in a MIB are defined using ASN.1 (Abstract Syntax Notation One) subset called "Structure of Management Information Version 2 (SMIv2)". For parsing we use MIB compiler.

Simple Network Management Protocol, SNMP - Part 1

Simple Network Management Protocol or shorter SNMP is protocol for managing devices on IP networks. Its predecessor was SGMP (Simple Gateway Management Protocol) and was intended to be replaced by a solution based on the CMIS/CMIP (Common Management Information Service/Protocol) architecture.

LDAP - Lightweight Directory Access Protocol, Basics

In every distributed system with many users and centralized user management, there is need for database which will contain base informations on every user. This database in Microsoft environment is known as Active Directory (most common choice) and in UNIX environment that database is called LDAP or Lightweight Directory Access Protocol.

Cisco refresh for switching / routing segment

Cisco has confirmed significant updates to its major Ethernet switching lines, as well as disclosed plans for a major upgrade cycle on its key integrated services router (ISR) line.

Among the big changes on the switching side are that Cisco has added 40G Ethernet to the Catalyst 6500 and also added 40/100G Ethernet to its Nexus 7000 data center switch.

Dynamic Host Configuration Protocol - DHCP - How It Works

OK, now when we know what is for, lets explain in simple words how DHCP works. There are few types of messages associated with DHCP; DHCP discover, DHCP offer, DHCP request, DHCP acknowledgement, DHCP information and DHCP releasing. For IP address association first four types of messages are intensively used.

Dynamic Host Configuration Protocol - DHCP - Introduction

DHCP? Hm... Well I think I heard this term somewhere... Yes, yes I have, but what is it, what is its main purpose?

Well, we are most glad to offer You explanation of DHCP. Its name, purpose and mechanism behind it. DHCP stands for Dynamic Host Configuration Protocol, this protocol isn't mandatory for your network to operate properly, but it's hell lot easier to have it configured in your network, specially if you have lot of computers and devices.

Routing Information Protocol (RIP) - Routing Legend

RIP in short

The RIP or Routing Information Protocol is a distance-vector routing protocol that uses hop counts for its metrics. That means that RIP prevents routing loops by limiting hop counts, to be more precise 16 of them. If more than 16, packet is discarded. Although old and not so scalable, RIP is even today widely used in local networks throughout the world.

16-year old Arfa Karim dies after heart attack

Arfa Karim

IT blog probably shouldn't publish info about someones life end, but this story touches both regular and IT world. For those who don't know Arfa Karim was a sixteen year old girl from Pakistan, the youngest ever Microsoft certificate holder.

DNS - Domain Name System. Basics, Zone files

A zone file describes or translates a domain name into the hosts, characteristics and services provided in the way that is recognisable to DNS software. If zone file is badly configured it is possible that your domain won't be available, mail for your domain won't be delivered, etc...

If badly configured, zone files can be cached on other DNS systems for hours, day, even weeks with faulty configuration and that represents great problem. In zone files we can do (what we call forward mapping) conversion of hostname to IPv4 or IPv6 address or we can do conversion of IPv4 or IPv6 to hostnames (reverse mapping).

DNS - Domain Name System. Basics, DNS Record Types

DNS record types

DNS resource records (RRs) describe the characteristics of a zone (or domain) and have a binary or wire-format, which is used in queries and responses, and a text format used in zone files and which is described in this chapter.

We will describe only few RR types, full list of DNS RRs can be obtained from IANA DNS Parameters.

DNS - Domain Name System. Basics, Types of DNS servers

Types of DNS servers

As we stated in previous part of DNS tutorial, here we'll talk about types of DNS servers. This is only theoretical part, as time passes by we will put some tutorials on DNS server configuration, but for practical part you need theory knowledge.

There are several types of DNS server:

• Master (Primary) server
• Slave (Secondary) server
• Caching (Hint) server
• Forwarding (Proxy) server
• Authoritative Only DNS server
• Stealth DNS server
• Split Horizon DNS server

Wikipedia is safe for at least one year!

Thanks to good people and their generous assistance we are privileged having the largest knowledge database on Internet available for at least one year. Banners with messages of Jimmy Wales, Jay Walsh, Sue Gardner and other Wikipedia staff are moved from Wikipedia, which means that fundraising was successful.

The site's fundraising efforts for the year have ended, and the Wikimedia Foundation was able to gather a record $20 million during this action. The content on Wikipedia serves more than 470 million people every month and has more than 20 million articles in more than 280 languages. The Wikimedia Foundation has been raising funds each of its 11 years of existence and has broken its previous years funding each year. The Executive Director of the Wikimedia Foundation, Sue Gardner, wrote in a press release, Monday morning, that their model "is working fantastically well.".

This year campaign was most successful one and we wish them at least hundred more.

DNS - Domain Name System. Basics, Namespace structure

Domain Namespace

Domain Namespace is, in fact, hierarchical and logical tree of domain names. Except "global" namespace, organizations can create their own private namespaces that are not visible from Internet. Domain namespace consists of root domain (which is nameless) from which we have generic top-level Internet DNS domains (gTLDs) and country code Internet DNS domains (ccTLDs), then in lower branches or nodes we have our domains and sub-domains.



Structure of Domain Namespace

DNS - Domain Name System. Basics, Part 1

You like just to sit at your computer, open your favorite Internet browser, type domain of web page and surf? We all do, but what is mechanism that lies behind that cosy Internet surfing. That mechanism is called Domain Name System or DNS.

DNS is not the only mechanism that enables us to surf on the Internet, but certainly makes it a lot easier. What DNS exactly does? Let's put it this way, it enables you to reach your destination by name rather than its numerical address. I think you'll agree when I say that is lot easier to type: www.google.com than to remember (and to type): 173.194.69.99, which BTW is only one of Googles IP addresses.

Cisco vs. Juniper

For last 15 years we are witnesses of constant battle between Cisco and Juniper. The argument began in 1996 with Juniper founding; until then, Cisco had ruled in both the enterprise and service provider markets since its founding in 1984.

Juniper first year was sponsored by AT&T, 3Com, Ericsson, Lucent, Nortel, Siemens/Newbridge Networks and UUNET. At that time Juniper started their serious competition for service provider segment. The Juniper position was strengthened by IBM decision to develop new ASIC for their Internet routers, the first of which was M40.

Cisco isn't standing still. It's been re-energized by the emergence of Juniper and the recent gains of Alcatel-Lucent in service provider edge routing. In 2009, Alcatel-Lucent leapfrogged Juniper's nine-year hold on the No. 2 market share position in the service provider edge, according to Dell'Oro Group. 

And Cisco still holds the lion's share of the enterprise and service provider router market, with a customer base that's mostly loyal to its incumbency. But it is Cisco and Juniper that try to leapfrog each other technologically in the service provider core and edge. Right now, the multi-chassis core race pits Cisco's Carrier Routing System against Juniper's T Series for tens – even hundreds -- of terabits supremacy.

Juniper is taking the battle to enterprise data centers and cloud computing environments. Emboldened by its success in carrier routing, Juniper unveiled enterprise Ethernet switches two years ago in an attempt to become a credible alternative to Cisco's dominance in that market, too. The company believes it can carve a niche in the elite networking arenas of financial trading, high-performance computing and other demanding enterprise environments just like it did in service provider routing.

In the data center, both companies are surrounding themselves with high-profile partners to help push their competing visions: Cisco with EMC and VMware, and Juniper with IBM. At stake, just as in service provider routing, is a multibillion dollar opportunity – $85 billion in private clouds by 2015, according to Cisco – to become the primary supplier of next-generation data centers, further entrench new and existing customers, and lock its rival out of lucrative, big ticket accounts.

Verizon 3rd 4G problem this month!

Verizon customers were faced with new 4G problem in their provider network. This is third time this month.Verizon, which claims to be "most stable" mobile operator in US announced that only data connections using 4G are affected, but is this true?

Their customers would disagree, because on official support forum there were many customers claiming that 3G and 4G don't work, especially in Phoenix area . Problem was solved during the night, but how will this "commercial" affect their customers satisfaction? We only guess that AT&T, T-Mobile and Sprint are rubbing their hands right now.

IT in 2012!

Now at the end of 2011. which was no dream year for IT (or for any other sector), we ask one question: "What will be with IT in 2012. ?". Except ancient Mayas prophecy about end of the world, it seems that there is no good news for IT sector in 2012 too.

Many big international companies like Ericsson, Nokia Siemens Networks, Alcatel-Lucent, Siemens, etc... are in trouble finding customers for their new products. Some of them even announced big dismissal of their employees. That is a sad sad truth about upcoming 2012.

This year we were witnesses to social networking boom, the next step should be cloud computing, say some experts. But due to instability in Eurozone and other parts of the world, we don't expect that firms will have money to invest in any aspect of IT modernisation.

If you are out there with job in IT world (and you like having one), conceal yourself until 2013.

Have yourself a merry little 2012!

Yet another blog about IT!

Howdy!

Nowadays, it is almost impossible to even go to toilet without IT is mentioned. We have electrical toilet seats, for few years (when IPv6 comes into play) every toilet paper holder will have IP address for some reason.

Enough with jokes, there are many blogs and sites about particular IT subjects... But, how many of them are serious and how many have the quality. They often don't provide insight to most of aspects in IT. Here, we will try to concentrate on basic topics from A to Z, we will try to provide as many tutorials as we can. Who knows maybe, if we have good start, we form community and forum and many many more things... :)

We are opened for suggestions of any kind, so please comment, e-mail us, shout, ...

And if You think we're wrong @ any subject, topic, etc... feel free to comment that as well.

Have nice reading!