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Category Archives for "How does the internet work"

INE R&Sv5 Workbook Full-Scale Practice Lab1 made in GNS3

How does the internet work - We know what is networking

Yesterday INE finally added a Full-Scale LAB in their new CCIE Route and Switching blueprint 5 workbook. I realized this morning that you maybe don’t want to spend half of your day (like me) configuring this topology in GNS3. Better to just take it from here and start your lab right away. In my study […]

INE R&Sv5 Workbook Full-Scale Practice Lab1 made in GNS3

What is the difference between tunnel | transport mode in IPsec

How does the internet work - We know what is networking

Intro IPsec making VPN connection possible. I enables to basically simulate a leased line across public Internet and thus enable us to get secure connection across unsecured environment. It enables encryption, authentication and protection of our data when sent across insecurity of the world’s biggest internetwork – Internet. It’s the cheap way to simulate a leased […]

What is the difference between tunnel | transport mode in IPsec

BGP dampening – punishment for unstable BGP prefixes

How does the internet work - We know what is networking

BGP prefix flapping can be caused by different issues in network. Basically every unstable network where links are unreliably and are going up and down here and there can cause BGP prefix flapping. Every prefix flap will cause some networks to became unreachable. BGP process will then need to recalculate best-path in order to hopefully […]

BGP dampening – punishment for unstable BGP prefixes

Source-based routing in IPv4 and IPv6 networks

How does the internet work - We know what is networking

In my current studies I did some work about security inside networking data paths. In my recent work I tried to get some experiments done that needed to use source based routing in order to be completed. Like most of scientific work that tries to get from paper to experiment and then to something useful, it failed […]

Source-based routing in IPv4 and IPv6 networks

VXLAN – Virtual Extensible LAN

How does the internet work - We know what is networking

As the time goes by and the network with more and more virtualised servers and other devices are making that network more complicated, overlay technologies are rising to save the day for network administrators. Virtual Extensible LAN – VXLAN is a new encapsulation technology used to run an overlay network on current Layer 3 communication […]

VXLAN – Virtual Extensible LAN

Redundant Default Gateway solutions in IPv4 networks

How does the internet work - We know what is networking

This article is an introduction to different default gateway solutions. Those technologies are enabling devices on IPv4 local subnets to have more than one Default gateway configured or at least some configuration that make them work half the way of ideal redundant solution. Idea behind this article is to be an introduction to a set […]

Redundant Default Gateway solutions in IPv4 networks

ICMP – Internet Control Message Protocol

How does the internet work - We know what is networking

ICMP protocol is a bunch of error, queries and response messages that are helping us every day to troubleshoot and manage our networks. At least if you found yourself in a networking engineer role. Network protocol “ICMP” is known as a control protocol because it is used for the purpose of administration and management within an […]

ICMP – Internet Control Message Protocol

Troubleshooting EIGRP Neighbor Relationships

How does the internet work - We know what is networking

EIGRP internals and getting hands dirty in debugging routing adjacency and solving EIGRP neighboring issues. What is sequence TLV and Conditional Receive CR-mode and CR flag Couple of days ago I got a strange network behavior in my CCIE lab. Something was wrong between a router and L3 switch connection and there was EIGRP neighbor […]

Troubleshooting EIGRP Neighbor Relationships

CCIE RS v5 blueprint will be announced this month?

How does the internet work - We know what is networking

Please note that this article is more or less pure speculation. The fact is that CCIE R&S v5 blueprint will be presented 28th January 2014 on Milan’s Cisco live event everything else is yet to be announced. From Milan’s Cisco live 28.1.2014 there is an CCIE R&S v5 blueprint event scheduled. When Cisco wants to […]

CCIE RS v5 blueprint will be announced this month?

Forwarding UDP broadcast traffic mechanisms

How does the internet work - We know what is networking

We will speak here about some basics about Forwarding UDP broadcast traffic. If you were wondering what Forwarding UDP broadcast traffic actually is I will try to explain it here in few words. If you have more that one broadcast domains in your local network, let’s say that you have three VLANs. In normal networking theory it’s normal […]

Forwarding UDP broadcast traffic mechanisms

MPTCP – Multipath TCP

How does the internet work - We know what is networking

Intro Multipath TCP is an extension of TCP that will soon be standardized by IETF. It is a succesful attempt to resolve major TCP shortcomings emerged from the change in the way we use our devices to communicate. There’s particularly the change in the way our new devices like iPhones and laptops are talking across network. All the devices […]

MPTCP – Multipath TCP

Administrative Distance for Static Route is 1 or 0?

How does the internet work - We know what is networking

There are different documents and books which are claiming that Administrative distance for static routes configured using exit interface is 1 and for the static route configured using next-hop IP address Administrative distance is 0. R1(config)#ip route 20.0.0.0 255.255.255.0 10.10.2.1 R1(config)#ip route 20.0.0.0 255.255.255.0 fastEthernet 0/0 This is not true. Both of them are having AD […]

Administrative Distance for Static Route is 1 or 0?

Difference between defining static routes with next-hop address or exit interface

How does the internet work - We know what is networking

There were a bit of confusion in my head about this case. It was not clear to me what is the difference between setting the static route using next hop interface IP address or using exit interface syntax. It seems that both methods are the same and that you have basically two different ways to […]

Difference between defining static routes with next-hop address or exit interface

IPv6 Implementation beyond theory & How playing with RA messages may be issue-istic

How does the internet work - We know what is networking

Some of this things I read in books and some of them took me few days of troubleshooting and sweating to get to them so I give them for free here to save you fellow networker some time: SLAAC The mighty SLAAC is the prefered method of IPv6 allocation, but is it so mighty? Or it […]

IPv6 Implementation beyond theory & How playing with RA messages may be issue-istic