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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4
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2answers
197 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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1answer
2k views

Difference of data transmission between wired and wireless networks

Is data transmission different between Wired and Wireless network? In other word, when talking about TCP/IP, does it mean that TCP/IP stack is not suited for wireless networks?
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1answer
1k views

How to capture GTP-C Traffic using mininet? [closed]

I am trying to capture the GTP-C packet, I am using Scapy to generate GTP-C Packet. But I could not find any good tutorial related to "How to use Scapy?"
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3answers
967 views

Cisco 3750 switch to Cisco 1841 router to Cable Modem?

I was rushing to help a friend out today who was trying to get a 3750 attached to a 1841 behind a cable modem. He called me at the last minute and figured it would be simple considering his needs were ...
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1answer
316 views

Change MTU without infrastructure change

It's very strange issue, on openstack cluster we have VxLAN between network and compute node and its using 1450 MTU (1500-50) because of encap header. Because of it some of my application not working ...
2
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1answer
474 views

Layer 2 Failover

How can I setup a layer2 failover configuration? My Network setup: The distance between Site A and Site B is 2 km. Both sites are connected via a wireless link. As a backup line, we also have a ...
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2answers
822 views

Subnet and routing on IPv6

I would like to know: 1) What is the smallest routable subnet size in IPv6 ? 2) Can a /128 address be routed in a IPv6 network?
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2answers
2k views

Gateway changing source MAC address in packet headers

My question might be broad but I was watching a Youtube video and thus I want to ask the following: Is it true that a gateway may change the source MAC address of some packets passing through it to ...
2
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2answers
55 views

DHCP does every host know of ongoing requests?

When a new hosts joins a network and broadcasts to find a DHCP server every host on the netowkr knows of the new hosts and its' request. Does every host also know of the final ACK packet, that ...
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1answer
66 views

The actual definition of network configuration

I've read this SDN paper that mainly discusses: Malicious administrator problem, where a network administrator misconfigures a correctly functioning controller in a way that adversely affects ...
8
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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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0answers
3k views

Tunnelling difference over VXLAN vs NVGRE vs GENEVE [closed]

Any bullet points that are most imp points when it comes differences between these three tunnellings VXLAN/NVGRE/GENEVE in networks. Found some notes here, anything that you may like to add would be ...
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2answers
540 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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1answer
132 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
348 views

What is purpose of router?

According to OSI reference model layers communicate with lower layer to transmit information on to other network. So they add header and tail for data and pass it on to lower layer and finally passed ...
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2answers
2k views

TCP Client-Server with mtu is set, Issue with fragmented packets

I have written tcp client-server, server will read a socket, and client will written packets to that socket. Mtu : 1500, packets will be fragmented if size exceds mtu. Case 1: When i did ...
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1answer
31 views

Access-list is it the same command of Access-group?

Is Access-group the old command of the Access-list for old routers? or they're just complete each other because when I do an Access-list I need to go to the port and use Access-group. Or they are ...
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1answer
560 views

Connect between two branches [closed]

Hope anyone help me to inform me how can connect between two branches & what the technology use it and what devices need to pay on this project? ? Sincerely,
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1answer
37 views

What does the load balancer shall have the ability to serve traffic over a static IP address mean?

I am doing research on SDN (Software Defined Networks), I do not understand the concepts of this question the load balancer shall have the ability to serve traffic over a static IP address I ...
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2answers
264 views

Does a router that connects to multiple networks, has a network card and forwarding table for each connection?

Say we have a router that connects to other routers and they connect to lan networks, does that router have a network card for each router it connects with but a single forwarding table for all? or ...
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1answer
199 views

How to send rate control packet in TCP/IP model? [closed]

How to send rate control(250Kb/s, 500Kb/s) packet in TCP/IP stack? Because In my understanding after tcp buffer filled then the Tx packets happening. Is my understanding is correct then How do I send ...
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0answers
321 views

GTP support in OpenFlow

I know there is a "tunnel id" metadata matching field which was introduced in the 1.3 openflow release, if I'm not mistaken. However, are there any actions in supporting the encapsulation and ...
2
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1answer
1k views

Duration of TCP connection last in idle state(no data exchange)?

What happens when we create the TCP connection and we wait while(1) i.e. infinite loop, Does it get terminated automatically? or It will last forever if my connection is very good
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2answers
302 views

What is VPN? How is it different from SSH? [closed]

I read wikipedia page ;but it says that we can extend over private resources publically. and user can send - receive data using public network to remote resources in perspective that it is connected ...
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1answer
830 views

Subnetting - Reason for maximum number of subnets [duplicate]

I'm new to networks and I was watching this video on Cybrary on Subnetting. The example h explained goes like this: Q. Subnetting 192.168.1.10/27 with subnet mask 255.255.255.0 He said 24 bits are ...
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1answer
1k views

Vlan Extension vs VPLS + need understanding

I have tried to find the answer online and I was trying to make sure my understanding is correct. So if someone can point me to the correct path please do. My understanding of vlan extension are ...
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2answers
143 views

BGP Question please

Would like to ask a BGP question; in the first link picture there is no direct link on the two bottom layer3 switches but they form a ibgp neighbor with each other. In the second link picture, the ...
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0answers
73 views

Would you recommend IPtables/Netfilter as a main firewall for an ISP? [closed]

As the title says. And since we are doing our own Support. Would it be recommended? I am talking about the Main firewall of the ISP, the Firewall that routes your data to the Router before exiting to ...
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1answer
72 views

Satellite network hardware

I'm having some problems with the selection of components for the construction of a satellite network. For communication with satellite, I want to use DS-CDM 760 modem from Comtech. But there is a ...
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2answers
428 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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1answer
337 views

Can we replace the MAC address with an IP address? [closed]

In the OSI model, Layer 2 uses MAC addresses, and Layer 3 uses IP addresses. Suggest and explain a way to replace MAC addresses with IP addresses, such that a MAC address is no longer required, and ...
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1answer
549 views

iBGP vs eBGP peering with ISP

We have Default routes till date with our ISP and now we are planning to run BGP with ISP, reason we want RTBH triggering. Question: Do we need to run eBGP or iBGP? If we run iBGP then does our ...
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1answer
153 views

Cisco restrict MTU size

Is there an any option in cisco Router we can restrict MTU size to something smaller? default is 1514 but for experiment i want to allow 512 only and if packet if bigger than 512 discard them.
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1answer
837 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 ...
0
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1answer
33 views

Data downloaded while upgrading to Windows 10? [closed]

Here is case: I have many PC's/Laptops which has windows 7 or windows 8. I wanted to upgrade all of those machines to Windows 10. All we have is wireless connectivity. No ethernet cables are used for ...
2
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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 ...
2
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3answers
753 views

Does TCP improve the ability of IP to send really really large files? [closed]

How does TCP improve the ability of IP to send really large files? Show me the math. (Calculate the max packet that IP can send and multiply by the maximum fragments. Compare that to what TCP can do.)
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2answers
182 views

Random latency on a wireless LAN

I'm facing a weird situation. Office LAN configuration is : A Netgear router as the main router An Ubuntu PC with UniFi controller software 10 UniFi APs At anytime, the latency between a computer ...
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1answer
2k views

What is RTAG7 hash

I am trying to read about RTAG7 hashing in ASICs. I am unable to find good literature on it. Can someone please explain what is the RTAG7 hash?
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1answer
106 views

Determine the number of hosts from IP address prefix [duplicate]

Is it possible to quickly determine the number of hosts by giving only the IP prefix such as /24 ? Thank you.
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1answer
73 views

How to assure where the problem is occurring? [closed]

I actually posted this question yesterday. I'm here to ask you guys again after testing. ↓↓↓First of all, please see my question↓↓↓ My customers told me that the access speed is really slow markedly!...
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1answer
78 views

How does distance play a role for total transmission time?

I've found a similar question in this site but the answers were not convincing me enough so I'll make a small scenario of two routers to express my point: Two routers connected by a link of rate 1 ...
2
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2answers
228 views

Measure the distance between hosts

In graph theory, the length of an edge is mostly represented by a numerical value to indicate the distance between the two end nodes. Thus, in the field of networking, is it acceptable if someone uses ...
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2answers
59 views

What NIC card should do before transmission

When a computer X is about to send a set of frames over the network to computer Y, should the NIC card of the computer X notify the other computers' NIC cards on the same communication link before ...
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0answers
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
90 views

2 Access Point in Long Floor - [Device Prefer Problem]

We have 2 pcs Cisco WAP300N and working on Access Point mode. This devices setted in a long floor. Also LAN cable connected to each one. And SSID's are the same. Problem; When someone starts to ...
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1answer
876 views

How to find the end-device causing high cpu usage in a Cisco switch? [closed]

While checking: sh proc cpu history there is high CPU utilization which occurs at a particular time.
2
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1answer
265 views

Understanding the effect of transmission rate change in network

Suppose there are 4 switches connected using a normal ethernet cables of speed 100mbps as follows: (S1)---100mbps---->(S2)----100mbps--->(S3)----100mbps--->(S4) Now suppose the link between ...
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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
126 views

connection between two pc without switch

I am new to networking. I have a small confusion. Can two pc be connected directly using straight through cable without any router or switch?