Questions tagged [ip]
For questions about Internet Protocol (IP), an OSI layer-3 network protocol. There are two current IP versions in use: IPv4 and IPv6.
861
questions
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2answers
27 views
Is it possible that multiple devices (servers) have the same external ip? [closed]
When I check devices' external IP (ipv4) from my home I see the same numbers for my phone and laptop. Imagine these devices are servers, both host different sites, and have 80 ports opened. From which ...
0
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0answers
6 views
Are there STUN implementations that can sometimes handle symmetric NATs? [closed]
I've been working on connecting two devices that are each behind a symmetric NAT and managed to make it work quite consistently. However, it takes quite some time for the connection to happen (...
0
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0answers
18 views
Find out location of public IP address [closed]
Recently we have fallen into a discussion with a company that provides us SaaS solution.
We like to have our requests directed to servers in Europe, instead of USA to have better performance. So they ...
1
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2answers
22 views
rules regarding IPV4 fragments and piecing them together
I'm rolling off my own TCP/IP stack for DOS and I have a question on IPV4 packets.
Assuming that a client sends multiple IPV4 fragments, I would predict the MF flag would be set for every fragment ...
0
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1answer
44 views
How is the subnet mask detected over the internet with CIDR (classless inter domain routing)?
Lets say there are two public IP addresses. One is 21.120.12.8/16 and the other is 21.120.12.8/8, they are different network IDs but when used over the internet how are they both differentiated? Or is ...
3
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1answer
38 views
Recommended IPv6 prefix size for PPP to a single host?
I am using PPP to create a IPv6 connection to a remote host.
What is the recommended IPv6 prefix size for a single host at the other end of the PPP connection?
Should it be /128, because there is ...
-1
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1answer
33 views
What is the maximum number of networks in IPv4?
From my understanding, in IPv4 addressing, the first 2 octets identify the network, meaning 2^16 networks can exist. But that doesn't seem even closly enough as the population in even USA is above 300 ...
1
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1answer
22 views
IP flow interpretation on Logrhythm Netmon
We have a Logrhythm freemium network monitoring solution depending on port mirroring using span ports on switches to receive all traffic and analyze it. But I cannot understand the output.
If I am ...
1
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1answer
67 views
Why do we need ATM if SONET/SDH can carry IP directly?
If SONET/SDH can carry IP, and ATM rides on SONET/SDH, then why do we need to encapsulate IP inside ATM?
That makes "IP over ATM over SONET/SDH". What's its benifit over "IP over SONET/...
1
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2answers
49 views
Basic conceptual questions about network interfaces
I have some basic questions as I am trying to understand the concept of network interfaces a bit better.
Is network interface same as network interface card (NIC)? If not, what's the difference.
What ...
0
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1answer
57 views
How to configure IP addresses in cisco packet tracer?
Hello I am working with Cisco packet tracer. I have two laptops connected to a wireless router with IP addresses assigned using DHCP. The router's Internet IP address is 10.1.0.0 and the LAN address ...
0
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2answers
20 views
Basic question in finding the port of a website
To my understanding, every time someone is hosting a service e.g. mysql server, there is always a server IP (or domain name) and a Port needed to reach the service (e.g. www.servername.com:3306).
...
0
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1answer
23 views
IP masquerading and nat
what is the difference between IP masquerading and nat?
do both of them have the same limitation?
in the line "IP masquerading cannot provide full internet connections to the hosts which hide ...
0
votes
1answer
40 views
Does every link between routers demand a new subnet?
This might be a stupid question but I'm new to this.
I am studying a class about basics of networking and I don't really understand one question that we have.
We need to a divide the given IPv4 ...
0
votes
1answer
15 views
How to ensure packet was created within certain time?
I am creating a custom protocol over UDP and I want to use a low number of bits for the sequence number. This means that the number can wrap relatively fast. Is setting the TTL for the outgoing ...
1
vote
1answer
59 views
How does Network Layer behave when client received a unicast DHCP offer?
I went through various stack exchange post to understand the concept of DHCP offer when it comes as a unicast to client from the DHCP server.
A server can send a unicast DHCP offer since it knows the ...
0
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0answers
12 views
How does 2 computers both behind NAT routers handle communication? [duplicate]
Currently reading up on TCP/IP protocol stack, while I was reading about the Network Interface layers, I started reading about NAT, and how it meant to decrease the amount of IPv4 used, by using the ...
0
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0answers
10 views
Into how many subnets can you split this address range up at most? [duplicate]
Let's say there is address range given: 124.33.66.0/23.
Into how many subnets can this address range be splitted up at most if each of these subnets includes at least 5 devices?
I don't know where to ...
0
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0answers
11 views
What is the use of a host mask/ wildcard with respect to subnetting and ranges? [duplicate]
Taking the example of 10.0.0.0/20, that means my range is 10.0.0.0 to 10.0.15.255 I got that range because I know that the wild card is 0.0.15.255 and I just add it with the beginning address 10.0.0....
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2answers
29 views
Huawei AR207V - can't set IP address
I can't set an IP address on a Huawei AR207V router because it rejects the "ip address" command.
It's a used but factory reset unit, I'm currently connected on the serial port no other ...
1
vote
1answer
32 views
Confusion regarding possible IPv6 Link Local address prefixes
I have trouble understanding how many alternative link local IPv6 address prefixes may exist.
I know that the prefix is fe80::/10 which implies that the first 10 bits must be static as:
| 10 ...
0
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3answers
46 views
How to find specific device in a network without brute force?
I have an Internet of things (IoT) device with known MAC address, which is connected to a network. First, lets assume that this network is large (subnet 255.255.0.0). Is there any "smart" ...
0
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1answer
77 views
How to construct firewall rule from 52.112.0.0/14 [duplicate]
I am trying to create a firewall rule to allow Microsoft Teams thru my firewall. I can see here https://docs.microsoft.com/en-us/microsoft-365/enterprise/urls-and-ip-address-ranges?view=o365-worldwide#...
3
votes
3answers
95 views
What are the administrative procedures for moving the geographic location of a network?
Original Question
Suppose that Alice operates a website hosting business in Maine. She has a warehouse full of servers to which a /28 range of public ipv4 space is routed (call it the W.X.Y.Z network)....
0
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1answer
37 views
Loopback interfaces subnets [closed]
Assuming that loopback interface is always alone in its network, what are the practical reasons to have IPv4 subnet prefix shorter than /32 for these interfaces?
Moreover, why according to various ...
0
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1answer
15 views
IP router not forward the packets it receives [closed]
I have been searching for a answer to this and have not found a definite conclusion. Everything seems to suggest
In what cases may an IP router not forward the packets it receives?
My guess which ...
0
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1answer
42 views
Static Routing - host to host ping does not work (MikroTik)? [closed]
I'm trying to do static routing using actual devices. Below is my setup:
The left router is a MikroTik RouterBoard hAP lite.
The right router is a MikroTik RouterBoard hAP ac.
I want to ping from ...
0
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0answers
21 views
Beginner Basics; thank you in advance for your time and kind consideration [duplicate]
If PCs connected across the same broadcast domain can send and receive frames based on the MAC address and do not intend to leave the local area network, then why do they need an IP address? Since IP ...
1
vote
3answers
80 views
Combining NAT an tunneling
I was reading a text and a doubt came to mind. Suppose there is an interface in a router that implements NAT. That same interface is the extreme of a tunnel. If I was to send a message through said ...
0
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0answers
7 views
Optimize and Concretize Routing Table [duplicate]
Hello I receive that homework from my teacher and I can't understand this thing I have to optimize the routing table and then make it on CPT. But I have no idea, because I was ill when he/she ...
0
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1answer
30 views
what does IP masking mean in this paper?
SO on page 6 of this paper it says:
Furthermore, since there is the possibility that the
NN attempts to learn classifying the packets using their
IP addresses, as the dataset is captured using a ...
0
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0answers
19 views
Why do cellular IP modems have configuration settings for transparent modes
I'm working in an area with industrial cellular IP modems such as ones from the company Four Faith. A manual is available from the URL
On page 27/40 it describes a setting called "Transfer ...
0
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2answers
45 views
How many IP packets are sent for a smartphone image?
Problem
Let's say, my image file has a size of 2 megabytes. It is sent over TCP/IP/Ethernet.
I want to know roughly how many IP packets are sent.
The purpose of this example is to get better intuition/...
0
votes
1answer
37 views
How to connect to a machine which is sitting behind NAT router?
I have a server that needs to push a message to a client from which it received a request a few days ago. Now request which was received has the IP address of the NAT router behind which the client ...
1
vote
2answers
517 views
Safe to remove ip default-gateway?
We recently changed IP schemes from 192.168.x.x to 10.x.x.x In doing so, I noticed that the prior network engineer had ip default-gateway in the configuration pointing to an old default gateway that ...
0
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2answers
435 views
Is not 192.168.88.1 (192.168.*.*) always an “internal” IP address?
I had some headache with a proxy setup which I couldn't figure out. Turns out that only "127.0.0.1" and "localhost" were recognized as "localhost" or "internal" ...
1
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1answer
59 views
what is happening when a host receives a datagram with its MAC address as a destination but different destination IP
In a specific network say the host receives this datagram what is happening ?
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0answers
15 views
How do I determine an IP prefix? [duplicate]
I know barely nothing about computer networks.
I am currently porting some windows code to linux, using .NET core.
Some parts have not been implemented for linux, and determining an IP prefix is one ...
1
vote
2answers
77 views
How does a device get a response from a HTTP request without an open port on the router?
I don't know much about how TCP/IP works, so please bear with me here.
I was wondering how, when your computer makes an HTTP request from a random port(on that device) to port 80 on a server, it gets ...
0
votes
1answer
31 views
Are there broadcast/collision domains on non-Ethernet networks?
What if we have routers or hosts connected via ATM, Frame Relay, or SONET; that is, what if we have IP over SONET, IP over ATM, IP over Frame Relay, etc., do we still have broadcast domains and ...
1
vote
0answers
19 views
What is the best way to match packets across pcap files from different capture points? [closed]
I have multiple pcap files which contain data from different capture points in the network.
Previously I thought that by using the IP-ID field I can match the packets across the capture files but I ...
2
votes
3answers
189 views
Testing Secondary Static Route
I am in the middle of migrating to a new IP scheme. From 192.168.10.x/23 to 10.6.x.x/19. Our ISP handles layer 3 and we statically route from our L2/L3 Cisco 3750G switch stack to their L3 device.
...
1
vote
1answer
59 views
how data are fragmented based on MTU and MSS?
just to be clear.. if a sender wants to send a data of 1800bytes ( assuming MTU be 1500bytes
so MSS = 1500-40 (taking min ip and tcp header) = 1460bytes)
Then there will be three segments 750 + 750 + ...
0
votes
0answers
7 views
network question [duplicate]
can someone please explain this question and answer
Based on networks 10.8.16.0/22 and 10.8.31.0/21, which of the following is the BEST summarized CIDR notation?
A. 10.8.0.0/16
B. 10.8.0.0/19
C. 10.8....
0
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1answer
56 views
What flow control mechanism does ethernet uses?
Datalink layer is basically responsible for 3 major functions -
Error detection/correction - CRC is used by ethernet
Collision detection - CSMA/CD is used by ethernet
But I couldn't find what flow ...
0
votes
1answer
46 views
What if receiver changes its IP address during the transmission process?
Suppose I am sending data to a laptop with IP address say x but before data could reach its destination the laptop is moved to another network and now its IP address becomes Y.
Will the receiver still ...
12
votes
3answers
4k views
Why isn't multicasting more popular?
Multicasting seems provide an efficient method of routing networking traffic from a source to multiple end users, especially at this moment in time with teleconferencing, streaming media, online ...
0
votes
1answer
31 views
IP datagram route through a network utilizing ARP
Suppose I want to send an IP datagram from node D to node C . Each step I also want to list the MAC addresses of the source and the destination , as well as the source and the destination of the IP ...
0
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4answers
94 views
How common it is to see unknown IPs in logs?
I have a server that streams video to YouTube/Twitch. I see [UFW BLOCK] entries in logs. One IP is 220.133.236.166, the other is 194.26.25.8. Is it a common thing that a server is connecting to my ...
1
vote
3answers
414 views
Routing between completely separate private networks
I’ve got a request from a partner vendor
in a completely separate routing domain to directly route a /24 rfc1918 network on my rfc1918 internal network. The proposed solution has their handoff ...
