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A numerical label assigned to each device (e.g., computer, printer) participating in a computer network that uses the Internet Protocol for communication.

4
votes
6answers
367 views

Why is classful addressing considered waste?

I am trying to understand the addressing strategies. But there is something which I can't grasp. Maybe I am missing a very basic point, if so, I am sorry beforehand. From my researches, let's say, if ...
4
votes
3answers
60 views

How to prevent IP conflict when using VRRP

We are currently using VSRP (Layer2/3) where we have a single IP as the gateway per VLAN. We are considering moving to VRRP (Layer3) which requires 3 IPs, 1 virtual and 2 real ones. This means that ...
-2
votes
1answer
34 views

How are IP addresses assigned? [closed]

1) If I buy a new computer, I haven't connected to the internet yet, don't I have ip address? 2) if I get the ip in one county, IANA gives me the ip depends on my location (first numbers), if I ...
0
votes
0answers
8 views

Does TCP server has to run on public IP address only [closed]

I have interfaced a GSM (Uni4 SIM800) module to a Raspberry-pi-3B module using AT commands to run a simple TCP server, and another pair of GSM and Rospberry-pi to run a TCP client. Now the Telecom ...
0
votes
0answers
3 views

Is it commonplace / accepted to change an existing CIDR prefix to meet certain network requirements? [duplicate]

Say for example, you have an IP address with a CIDR prefix of /27 (mask of 255.255.255.224) and are required to create 4 subnets each with an equal amount of usable host addresses, would it be ...
0
votes
1answer
21 views

How to use a remote shell on a machine outside of network

I understand the differences between LAN and WAN addresses. My question is: while outside a network, how do you target a specific machine's address beneath a public IP? Since a public IP for each ...
0
votes
1answer
40 views

What is AWS ELB IP range for white listing in firewall? [closed]

I have AWS infrastructure running over AWS ELB (Classic Load Balancer) and EC2. I need to know IP range for AWS ELB in EU (Ireland) Knexusplatform-Live-SaaS-IR-1436765642.eu-west-1.elb.amazonaws.com, ...
0
votes
1answer
45 views

How to assign 2000 addresses starting from 198.16.16.0? [duplicate]

This problem comes from Tannanebaum's CN book and the full description of it is as follows: A large number of consecutive IP addresses are available starting at 198.16.0.0. Suppose that four ...
-1
votes
3answers
54 views

Why do we need an ethernet MAC address? [duplicate]

Don't think it's a duplicate. I've searched really many articles and couldn't find the satisfying answer. I understand : how ARP works MAC address is an unique address for each NIC IP is network ...
1
vote
1answer
42 views

Do RIPE Atlas probes need a public IP address?

I'm new to networking in general, and have only a vague understanding of network topologies. Looking at the RIPE Atlas info video, it would seem that any user can install a probe and that then gets ...
0
votes
1answer
30 views

Assigning IP Address ranges - Protocol, Best Practices [closed]

I am looking for standard procedures when assigning a range for static ip addresses. Which are the most commonly used approaches and why. I am trying to look on the internet and this forum, however ...
0
votes
2answers
45 views

Why router interface need IP addresses while IP is constant during the journey?

A beginner question, I've recently read in Cisco CCNA R&S 200-125 official cert guide that the packet leaves the PC with a destination IP of PC2 (the target) but with the MAC of PC2 in case of PC2 ...
1
vote
1answer
114 views

Find subnet prefix/CIDR from IP address and required No of hosts [duplicate]

I want to know that how can we calculate the Subnet prefix and CIDR, when the given information is only IP address and required No of hosts. For example: Suppose we have: IP Address= 198.1.1.0 and ...
4
votes
2answers
879 views

Why we use 224 as multicast address in many protocols?

I see in many protocols we use 224 multicast address as like eigrp uses 224.0.0.10 ospf uses 224.0.0.5 224.0.0.6
0
votes
0answers
7 views

How to find subnet mask using First and last usable IP address [duplicate]

The first and the last IP addresses of a subnet are 192.192.8.0 and 192.192.63.255 respectively. how to find the subnet mask?
2
votes
1answer
321 views

Can a 172.168.10.0/28 be a class B Subnet

I am starting my studies in networking and starting off with the basics of IP addressing and Subnetting with CIDR values. My Question here is 1st how can you tell the subnet class of an IP address ...
0
votes
1answer
37 views

How ARIN IP Address is used in APNIC Region? [closed]

Amazon AWS provides the following JSON (Source) which has list of IP Address ranges used by AWS. { "ip_prefix": "54.179.0.0/16", "region": "ap-southeast-1", "service": "EC2" ...
0
votes
1answer
53 views

What are the component names of CIDR Prefix Notation?

What are the components of the IETF's CIDR Prefix Notation called? 172.16.0.0/16 contains two parts: 172.16.0.0 /16 In the RFC the entire term 172.16.0.0/16 is defined as the "Prefix Notation" for ...
2
votes
2answers
57 views

Bad mask for Cisco simulator GNS3

I am using the GNS3 simulator, and I need to connect two Cisco C7200 routers. When I enter the ip address 126.0.0.4 255.255.255.252 command, I get Bad mask /30 for address 126.0.0.4.
4
votes
1answer
111 views

IPv6 - ULAs - Am I understanding use correctly?

Tinkering more with IPv6 and trying to unlearn the IPv4 stuff. Assume my router is correctly respecting the reserved addresses. LLIPs aren't going to pass through to the router's outside interface ...
1
vote
1answer
104 views

Why did Netflix choose to use CIDR blocks of 100.64.0.0/10 as its private network IP space?

Netflix gave a public tech-talk explaining their network, and one specific design puzzled me. See Page 25 at this talk (Netflix's Migration into VPC), they seemed to choose to use 100.64.0.0/10 as ...
3
votes
3answers
111 views

How to tell which one is the source IP and MAC address of the data being received?

I have to work with an FPGA module already running a code written by someone else. I have no access to the FPGA code. Now the setup is something like this:- FPGA is connected to the pc via ethernet ...
1
vote
1answer
74 views

What format is "1.34.128.0/113'?

I know of two format that use similar notation, Classless Inter Domain Routing (CIDR) and Variable Length Subnet Mask (VLSM). However the numbers after the / is usually less than 32. However in this ...
4
votes
3answers
290 views

Does Cell Phone use Public or Private IP address? [closed]

Does mobile phone/cell phone get a private IP address or public IP address? If the cell phone gets a private IP address, I assume that the telecom operator uses carrier grade Network Address ...
6
votes
1answer
104 views

Why is an IPv6 Link-Local Address a /10?

I'm currently studying for my CompTIA Network+ Exam and am a bit confused as to why the IPv6 link-local address is a /10 and not a /12 or /16. Since each character in an IPv6 address is 4-bits and ...
0
votes
1answer
49 views

Is it possible to append custom data to every packet of a request? [closed]

For an end-to-site VPN, i.e. where a device (VPN client) is responsible for encapsulating the GRE packet, is it possible to send some custom data along with the GRE packet beyond just the standard ...
2
votes
2answers
51 views

Before the invention of Classless Inter-Domain Routing (CIDR) did hosts have subnet masks assigned?

Before the invention of CIDR, did hosts also have a subnet mask assigned or only have an IP address and the network was determined by the class of the IP address?
0
votes
1answer
84 views

Which MAC should be used: device MAC or Interface MAC?

My L3 switch has ~30 interfaces. If you look at the output below there are two MAC addresses showing in the results of the show interface command. The hardware address is the same for all interfaces. ...
0
votes
2answers
65 views

Identify IP of the client causing high interface usage on uplink port

Background: We are observing a high interface load (spikes up to 1G) on a WAN (dedicated link) uplink port of a Cisco switch. How can we find the IP of the client that is causing this high load? I ...
0
votes
2answers
36 views

When neigbour solicitation and router solicitation are used to get the IPv6 address, then what is the role of 0:0:0:0:0:0:0:0/128?

I am learning computer networks, but getting confused each time I proceed my analysis. Kindly help. Thanks in advance!
6
votes
3answers
766 views

Why couldn't a nework address be used as as broadcast address as well?

I am taking a refresher on Networking and I found out that: Network address is an IP address with all 0s after the subnet mask Broadcast address is an IP address with all 1s after the subnet mask ...
2
votes
1answer
61 views

IP address that can not be reached from outside of device

I am sorry if this is a silly question, but I am developing an application that should connect to itself over sockets, but to make it secure it should only be reachable from local device. I believe I ...
3
votes
1answer
57 views

VLSM Determining Switch IP

i was given a network 130.4.0.0/16 that i needed to use vlsm on. which i did and got these vaules: Address | Mask| Assignable Range | Broadcast 130.4.0.0 | /22 | 130.4.0.1 - 130.4.3.254 | ...
3
votes
2answers
69 views

Does each router have the IP addresses of all the routers and hosts connected to the 'Internet'?

I am new to computer networking,and was reading about the topic routing. According to my understanding,each router has a routing table associated with it. From that table it could know,which output ...
6
votes
2answers
477 views

Is it true that the fd00::/8 address range (ULA) in ipv6 is for machines that you NEVER want to speak with anything on the Internet?

Is it true that the fd00::/8 address space (User Local Addresses) in ipv6 is for machines that you NEVER want to speak with anything on the Internet? I was just reading that here and rather surprised ...
2
votes
1answer
88 views

Working Out A Router IP Address

i am in my first semester of networking, in my exam i got completely derailed when i was asked to find the router ip address. i was given the following information about the network: VLANS: ...
5
votes
1answer
139 views

Class A most significant bits '0' as in RFC1166 or older or '00' as suggested in RFC4632?

I was just reading RFC4632 "2. History and Problem Description" and I don't get the part about Class A with MSB '00'. That would in my understanding mean, there are actually only 64 available networks,...
5
votes
2answers
147 views

IP Address starting with 253

I have no idea if this is the right place to ask this question, I'm very sorry if it isn't I have here data containing an IP address that starts with 253.45.xxx.xxx But I've looked up everywhere and ...
0
votes
2answers
107 views

Does the same IP cause IP conflict if one is from /22 other is from /24?

I have two hosts. They both have the same IP/subnet, ex.: 1.2.3.4/24 on both. I know this is bad, since there will be duplicate IP in the network. OK. But: If I have different (?) ranges: 1.2.3.4/...
5
votes
1answer
132 views

What's the domain of an IP?

CIDR stands for "Classless Inter-Domain Routing". But what's a domain in this case? Seems to not be the same kind of domain as DNS deals with...
3
votes
2answers
95 views

What provision does DS-Lite, as used by ISPs, have to provide IPv4 blocks to CPE?

I run a small ISP for a rural community in England. There are around 350 residential properties and 15 small businesses. Three of these businesses run systems that require two consecutive IPv4 ...
0
votes
2answers
260 views

How do ISPs configure a static ip in a double nat? [closed]

So I have an ISP which I requested a static ip. My ISP gives a static ip for a one time payment. So I decided to get one. My ISP does double NAT which by default all incoming tcp ports are blocked. ...
1
vote
1answer
112 views

Why would the local address in case of mobile data network not a private IP address? [closed]

I have connected my smartphone to internet over 4G through Airtel (ISP) I did - "What's my IP" on google. And below is the screenshot i obtained- I understand the public IP address is in the range ...
1
vote
1answer
62 views

Migrating from an IP addressing scheme to another one?

I have been tasked to migrate one of my customer's IP telephony network from 192.168.11.0/24 IP addressing scheme to 172.27.72.0/23. My customer has deployed Cisco Call Manager and Cisco Unity ...
0
votes
2answers
54 views

Will DHCP server know about the statically allocated IP addresses for any of the device under its purview? [closed]

For simplicity sake, let us say, the DHCP server is running in the default gateway/router at 192.168.1.1/24 And let us say, i have connected 10 hosts to the router. And among 10 hosts, 2 of the ...
1
vote
3answers
204 views

What is the need of two addressing schemes (physical and logic address) in networking to identify a host? [duplicate]

In computer networking, each device/host is assigned 2 different unique address. One physical address, MAC and one logic address, IPv4/IPv6, to make communication possible between any 2 hosts in the ...
2
votes
2answers
158 views

Ping loopback without interface IP address

I have two routers attached directly and both of them has loopback address. The interface has no IP address, I have just connected R1 g0/0 to R5 g0/0. If I put IP address on the g0/0 interface of both ...
-4
votes
2answers
758 views

ipv6 number of Host Address

I'm trying to find the number of host addresses of IPv6, I know the correct answer is 18.4 × 1018 I cannot seem to correctly calculate the formula to reach the correct answer, please help me. IPv6 = ...
4
votes
4answers
581 views

Are private IP addresses the outcome of subnetting a public IP address?

I understand the purpose of both but just verifying if this correlates together at all.
4
votes
1answer
355 views

CIDR notation and subnets

I've been given a script that will create a virtual network with the following IP range (in Azure): 10.0.0.0/16. The script then goes on to create two subnets within that network with the following ...