Questions tagged [network-core]

One of the three layers of network design. The main characteristics of the network core are that is should be highly redundant and high performance. As such, it is often one of the simpler layers in that it should not implement any services that impact performance. No user/server connections should be made to a pure network core.

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3answers
48 views

Why does a queue of a network device like router starts to fill up if the arrival rate equals the transmission rate of the outbound link?

In the book "Computer Networks: A Top Down Approach by Kurose" it is written that when the traffic intensity approaches 1, the average queue length gets larger and larger. Traffic intensity ...
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3answers
56 views

Understanding the ways of communication in IP networks

I am trying to check my understanding about the ways of communication in IP networks. I would classify the ways of communication in IP networks into three generic types: The source requests name ...
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2answers
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Can port mirroring be used to convert single video stream to multiple video streams?

I am new in networking and had a basic query regarding port-mirroring. A video stream is taken from camera-based software system and is being fed to a distribution system. For high availability (...
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1answer
30 views

OTN interface on router

In the IP over DWDM Wikipedia page, we see this sentence: (this link) "A true IPoDWDM solution is implemented only when the IP Routers and Switches support ITU-T G.709. In this way, IP devices ...
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2answers
92 views

Network ( routing and switching) , security

In my company network i am installing new cisco2811 router but i have problem, my LAN network can not ping and access network. i get point to point internet from ISP. PTP IP is 192.186.86.200/24 and ...
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105 views

Are there any alternative devices to routers?

I am not talking about the router used at home to access Internet . I am talking about devices used in the network core. I want to know if there are alternative devices, if any, used for forwarding ...
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1answer
26 views

Wants to understand traffic flow of Catalyst layer3 Switch 3850 . what are sequence this switch will check to delivery packet to destination

i wants to know clear understanding about how Cisco layer3 switch checks in sequence order when traffic arrive to its L3 Interface . i want to know traffic flow in Cisco layer 3 switch ,because switch ...
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1answer
101 views

Packet scheduling in LTE/5G core network components

Scheduling algorithms must be used on the radio side of these technologies in order to map radio sources to incoming/outgoing data packets and satisfy quality of service requirements such as latency ...
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4answers
68 views

P2P Connections

Hey there I am a noob in the field of networking and I have a confusion: What is the difference between point-to-point and end-to-end connection ?
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1answer
295 views

Symmetric routing and asymmetric routing plz elaborate

First of all thanks, Am pretty much confused this both term of routing read blog's and notes but still kinda confused.
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1answer
205 views

LTE EPC Synchronization between redundant components

I am investigating resiliency in LTE Evolved Packet Core. Each EPC components has information storage as defined for each user in 3GPP TS 23.40 (Ch 5.7). In case of failure this info needs to be ...
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1answer
912 views

Deploying Virtual Stackwise Catalyst 9400

I am looking into deploying Virtual Stackwise on the Catalyst 9400 series switches. I wanted to know based on best practices where should the VSL links be deployed on the Sups or the modules? Is there ...
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3answers
2k views

How to explain the data flow of OSI model layers in a single picture [duplicate]

Take an example of searching www.example.com in a web browser. I have some confusions at each layer and they are We have opened a web browser and searched for www.example.com. Now, As far as I know, ...
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680 views

What is the use of Phy and MAC chip?

Is it mandatory to have a MAC and PHY chip? Are these two chips within a NIC CARD? As I understand, these two chips are connected using RGMII or SGMII or xaui.
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2answers
2k views

In MPLS VPN, Which one become first? MPLS Label tag or VPN encapsulation?

In MPLS VPN network, which one is the first thing to do? I mean label tagging is first or VPN encapsulation is first? If you can, please explain about this case.
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3answers
12k views

Difference between CBR and FTP

I am new to networking. I have some confusions regarding CBR and FTP? Are they any protocols like TCP or UDP or something else? When do we use them?
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1answer
2k views

Quagga not announcing external routes over ibgp session

I have a problem when I try to achieve load sharing with bgp. My scenario is http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13762-40.html#conf3. Only difference to this is ...
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2answers
6k views

Are there any global network other than the Internet?

I found this definition of Global Networks: Currently does any Global Network exists (apart from Internet)? Can someone Quote some examples? Or non-global but on a country-wide scale(ATM network ...
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2answers
430 views

Network distribution/core design implementation

Can the Cisco 3650 do the job of distribution/core layer? We have at least 250 devices that will be connected to the network. More info : The Cisco 3650 is needed for inter-vlan routing.
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858 views

ASR 100X series hardware redundancy?

I have very little knowledge of the Cisco ASR series. We are planning to buy a ASR 1001X series router, but I have a question related to hardware redundancy. Do I need to buy two Cisco ASR series ...
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1answer
6k views

2960s and outdiscards

I have an issue with a pair of 2960s switches. I can see a lot of outdiscards on some of the interfaces and the end users are noticing network issues. I also have some access points that can't ...
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1answer
4k views

Understanding bisection bandwidth

I have trouble understanding the concept of bisection bandwidth in high performance computing clusters. Wikipedia article on bisection bandwidth, and online materials say that bisection bandwidth is ...
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1answer
2k views

Should I use the same Native VLAN for the management traffic network-wide?

I have the native VLAN on my trunk links set to VLAN 10 which is my management VLAN that spans the entire network. We have one WLC and Access Points connected on a trunk link set to native VLAN20 ...
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2answers
32k views

How to calculate sample RTT? [closed]

I am new to networking and figuring out that how to calculate sample RTT which will be used later to calculate estimated RTT, Here's my assigned problem: Suppose that TCP's current estimated values ...
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2answers
150 views

IP Domain-name on aggregation layer switch

Hi I was trying to generate ssh key for a switch I read that , ssh key is generated as a combination of hostname and domain-name I created a domain name like test But doubt is , why isn't the ...
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1answer
90 views

Are There Link Layer Switches in the Network Core? [closed]

Do we use link layer switches only in LANs, or are they deployed in the network core as well? I cannot picture the network core in my mind, is it just all routers starting from the edge router?
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1answer
3k views

value EstimatedRTT at first time?

What is the value of EstimatedRTT at first time? EstimatedRTT = (1-α) EstimatedRTT + α*SampleRTT Is it the average of all sampleRTT ? For example i have following SampleRTTs: 120 ms, 140 ms, 160 ms ...
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461 views

What are the significance of different types of routers?

Initially when I started learning networking, I understand the 'Switches' and 'Routers' are the core components of networking. As I started getting more into networking, I started hearing different ...
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1answer
282 views

Upgrading our Network to Managed Switch with Internet Routing

I am a business owner with multiple BT Buisness Broadband lines. We have two sets of VOIP lines and two sets of PC's, each with there own switch board. The problem that we have is that our lines go ...
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1answer
970 views

Should a Metropolitan Area Network (MAN) be setup with a router at each site?

Should a Metropolitan Area Network (MAN) be setup with a router at each site? Or, because the connections between sites are usually at layer two, should each site operate on one "master" switch which ...
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3answers
10k views

What is a headend device?

I see the term headend thrown around a lot at work? What sort of device in what role gets considered a headend?
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2answers
135 views

Separate a network within the enterprise environment

What will be the best solution, to securely separate a network and have internet connectivity. In an existing enterprise environment (Firewall, Dhcp, routers and switches) i will like to separate ...
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1answer
204 views

HSRP - 2 separate Virtual Router for Distribution and WAN?

I've got 2 Core-Multilayer-Switches connected with each other with two cables (trunks). They are also connected with the distribution-switches (and each switch is connected with both core-switches). ...
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66 views

what happens when a http request is sent into network [closed]

If a http request is sent in internet where the request will go and what will happen to the request after finding the IP address. For example what are all the work done by egress and ingress ,DCHP. Is ...
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2answers
9k views

Connecting clients to two networks using Mikrotik router [closed]

I have two networks Network 1 and Network 2 shown in the picture, and one client machine that must access resources on both networks. Due to security reasons the two networks must be isolated from ...
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0answers
769 views

Cisco Nexus 7k Mac move

I have been troubleshooting a mac move behaviour on my core network, which is made of 2 Nexus 7K with F3 series modules. They are inter-connected with a fabricpath mode port-channel. All the remote ...
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2answers
478 views

Unbundling local loop

When we are dealing with local loop, we indicate the last mile of connection from the CABINET (or whatever else) to the subscriber. Now, I'm asking to you, the local loop is the medium of the access ...
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2answers
76 views

Given a network switch, can we identify the devices (IP not assigned yet) connected to it? [closed]

If IP is not assigned to the server yet and suppose it is connected to a switch, then can we still get the details of the server from the switch?
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1answer
136 views

linux network card packet timestamping [closed]

Curious to know an application that uses hardware time-stamping presented in network cards. If you know any app uses this please list down here. I saw people writing application through UDP sockets ...
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4answers
3k views

L3 Core to Firewall question

I'm in need of some advice regarding the implementation of the network core layer of a network I need to design. I've found some similar questions asked (and answered) already, but none have really ...
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2answers
6k views

Cisco 3064 switch upgrade from 6.0.x to 7.0.x issue

I am trying to upgrade from 6.0.2.U6.5c to nxos.7.0.3.I4.7, before upgrade i want to make sure it pass all checks but i got this error. This switch isn't in production yet but want to make sure it ...
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1answer
79 views

How to use MCLAG for In Service Software Upgrade (ISSU)

In following video, the CTO of Arista claims that they use Multi Chassis Link Aggregation (MCLAG) setup for In Service Software Upgrade (ISSU) with zero down time on their switches https://www....
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2answers
199 views

WSN vs Ad hoc in real practice

Wireless Sensor Network (WSN) and Ad hoc Network differ in one important factor: Infrastructure-based vs Infrastructure-less. In WSN, network is managed by a base station such as these antenna around ...
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7answers
9k views

Cant ping & access HP switch on network connected on trunking mode

I have been facing this problem for a very long time. Here is a diagram of the switch situation: The problem is that I have been trying to access the switch on the RIGHT(A3100) through the network ...
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1answer
981 views

Cisco ACL for NTP

We have Cisco ACL configured for all inbound traffic and today i have add NTP to allow few remote NTP server to sync tim. I have created object-group NTP group and multiple remote NTP server in that ...
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2answers
416 views

Physical interface as switch port and VLAN interface as layer 3 [closed]

In most of large ISP networks, physical interfaces are used as switch ports (layer 2 port) and VLAN interfaces are used as layer 3. Could you please explain what is the main purpose to use like this?
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2answers
548 views

Internet throttling speeds in LAN network

Trying to troubleshoot low internet speed. We are paying for 200mb download speed. Our setup is as follows: Users computer(1GB) -> Phone(100mb switch port) -> Access switch(100mb) -> Core Switch(1GB) ...
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0answers
276 views

How does a Switch Fabric Module work internally?

I am interested how does a switch fabric module work internally. What interfaces does it use to physically connect the I/O modules on switches? Where are the CAM / MAC tables of the switch? Are ...
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2answers
197 views

Working of Application Protocol and TCP/IP Protocol

I was reading Steven's book on Unix Network Programming.There was a paragraph in chapter 1 which said: Even though the client and server communicate using an application protocol, the transport ...
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1answer
440 views

ASA 5585 licensing question

We have purchased Security Plus and output showing following, in Failover it's showing Active/Active does that means i can't configure Active/Standby ?? Licensed features for this platform: Maximum ...