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Amit Gupta

Top 10 HTC Phones Under Rs. 12000 Reviews

Looking for a good smartphone under Rs 12000? HTC have lots of them in the market. You can get a good HTC Desire series smartphone under RS 12000. Though these phones fall a little on the average side, they are great for the money. You can be sure you’re getting something that’s durable with a great camera, excellent performance, and average battery life.

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Mofluid Review- Why Mofluid Is the Best Magento App Builder.

Mofluid Review
Every business owner’s dream is to bring their goods as close as possible to their customer so they can access at the snap of a finger or better still at the click of a button.

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Infographic: The cost of cyber attacks in the US

Cybercrime is the greatest transfer of wealth in history, accoring to former NSA director Keith Alexander:

PureVPN Review 2016

PureVPN Review

VPN refers to Virtual Private Network that secures your online activity, giving you complete anonymity about your activities and presence on the internet.

User friendly and with minimum complexity, VPN works by imitating your IP to get to the restricted access without revealing your information to prohibited censors.

PureVPN offers you some of the great features which are most attractive to high end users.
[continue reading…]

What is MPLS?

Before going in a discussion that what is MPLS? The question is why we need MPLS?

 

Why MPLS?

  • We are in need of a single infrastructure that supports multitude of applications in a secure manner.
  • Provide a highly scalable mechanism that was topology driven rather than flow driven.
  • Load balance traffic to utilize network bandwidth efficiently.
  • Allow core routers / networking devices to switch packets based on some simplified header.

QinAny Mode

First of all the thing which is to be noted is that the QinAny mode is only supported by the Cisco XR 12000 Series Router.

Actually the QinAny mode is just like the or maybe you can call that it is similar to the QinQ mode using Type 5 virtual connection (VC), instead of that the customer edge VLAN (inner) tag will be carried into the packet while it is sent over the psedowire. This is just because the customer edge VLAN (inner) tag is not known by the configuration.

Basically in the QinAny mode, the service provider VLAN (outer) tag is configured on both the ingress as well as the egress nodes of the provider edge VLAN. [continue reading…]

MPLS Labels

Before discussing MPLS LABEL we must know about or the prerequisites of this section are

  • What are the types of MPLS?
  • What are the modes of MPLS?
  • What are the router roles of MPLS?
  • What is Push?
  • What is Swap?
  • What is PoP?

 

With MPLS we are going to make forwarding decisions not based on the actual IP header but rather based on the layer 2 and half of the OSI reference model Labels that are surgically injected into our Packets.

If we enable MPLS which is really simple by the way a command is “mpls ip” enter.

You do that globally, you do it interface config, your router is now mpls enabled. Now what it will do is that it will automatically take every single IP route which it learn from IP network not from BGP but any IGP learned route it will go and assign a local label for them.

  • Each router assigns a locally significant label for each IP route, and advertises these labels to neighbors.
  • Label Distribution Protocol (LDP) is used to exchange labels.
  • Uses the IP routing information to determine the direction and next hop to forward a labeled packet.
  • Does this before first packet even arrives.

 

MPLS LABEL

MPLS LABEL is simply a locally significant value that identifies a particular Forwarding Equivalent Class (FEC). An FEC is a group of packets that will be forwarded to the same next-hop IP Address and that are assigned the same level of treatment.

Each Label has four fields, totaling a 32 bits.

  • Label ( 20 bits )
  • Experimental / CoS ( 3 bits )
  • TTL ( 8 bits )
  • BOS ( bottom – of – stack, 1 bit )

RFC 3031 “Multiprotocol Label Switching Architecture” lists those 3 bits as “experimental”. In reality the Cisco IOS uses those bits for Code of Service.

The Time to Live (TTL) bits serves the same purpose as do IP TTL bits.

The BOS (bottom – of – stack, 1 bit) value is referred to in some MPLS documentation as simply “S”.

As mentioned earlier, a packet can have more than one label. The BOS bit will be set to zero on all labels except the very bottom label, which will have a BOS of one.

A packet can have more than one label. A label stack consists of multiple labels, one on top of the other. Labels in a Label stack do not interact in any way.

MPLS Labels MPLS Labels - complete

And It would not be Cisco networking without some kind of PID or RID?

In this case, it’s a PID. The MPLS PID indicates whether labels have been placed on the packet.

Ethernet Port Mode

Ethernet Port Mode:

In this mode both the ends of the pseudo wire (PW) are connected to the Ethernet ports. The port is tunneled pseudo wire (PW) or using local switching. This is also known as AC-to-AC cross connect) switches packets or frames from one AC to another AC are attached to the same PE node.

The pseudo wire is always a type 5 virtual connection (VC).

On the Ingress Provider Edge, the network service provider passes the packets to the pseudo wire termination point, and adds the MPLS (learn MPLS basics) labels to the packets, and sends the packets over the pseudo wire. [continue reading…]

Layer 2 VPN

L2VPN Concepts:

Layer 2  VPN emulates the behavior of a local area network (LAN) across an internet protocol (IP) or MPLS-enabled IP network allowing Ethernet devices to communicate with each other as if they were connected to a common LAN segment.

Internet service providers (ISPs) would like to replace their Frame Relay (FR) or Asynchronous Transfer Mode (ATM) infrastructures with an IP infrastructure. Accordingly, there is a need for to provide standard ways of using an IP infrastructure to provide a serviceable L2 interface to customers, specifically, to provide standard ways of using an IP infrastructure to provide virtual circuits between pairs of customer sites. [continue reading…]

MPLs VPN

VPN

In the past the old days we have layer 2 virtual circuits provided courtesy of our service provider
A virtual circuit would be an overlay normally from side A to side B. may be a frame lay link or ATM or SMDS, X.25 whatever it is. It is the overlay of the provider network.
If you have multiple sites you have full mesh, partial mesh, multilevel topology etc.
We also have overlay methods of IP Tunneling in which we have IPsec, GRE, and PPTP.
IPsec and PPTP has the benefit over GRE is the security but they doesn’t have the encryption.
So the GRE benefit is that of encryption. [continue reading…]

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