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.
779
questions
0
votes
2answers
33 views
Clarification on when routers encapsulate and decapsulate packets
I'm an application developer working on getting a working knowledge of network engineering, so basically a newbie. I've been trying to figure out exactly when routers decapsulate frames into packets ...
0
votes
0answers
15 views
TCP connection closes instantly (without timeout) when I change my IP address through the windows network and sharing center [closed]
I have tcp connection to some tcp server on internet. Tcp client is a simple application that I have created which works on my computer. The problem is that when I change my ip address through the ...
0
votes
0answers
15 views
Finding file transfer overhead [closed]
If this is not the right thread for this question, please bear with me and suggest the better one.
So basically I'm trying to setup an experiment to estimate a data transfer overhead through an ...
1
vote
1answer
34 views
IPv4 maximum datagram size
The IPv4 datagram consists of two parts:the header length and the payload. The maximum header size is 60 bytes and minimum is 20 bytes. The maximum size of the data can be 65515 bytes. So why the ...
0
votes
0answers
25 views
what enables cloudflare to disable direct ip access? [closed]
When I visit a website that has Cloudflare, using the website's ip address, I get this message:
Error 1003
Direct IP access not allowed
What happened?
You've requested an IP address that is part ...
1
vote
2answers
118 views
Can link local addresses be used for transit networks without breaking routability?
I am asking this because my ISP uses SLAAC/DHCPv6 to assign addresses to clients. Firewalls, no matter what brand/name/type get a link local IPv6 address complete with a link local gateway AND clients ...
1
vote
1answer
127 views
Broadcasting to unknown Class C Network
I am trying to use python to broadcast to my local network, and I cannot find a way to get the subnet mask. I have been suggested to use the default Class C network subnet mask 255.255.255.0, and use ...
1
vote
2answers
43 views
Where are broadcast packages filtered out
When I have one network with a switch. Within that network I have 10 PC. Halve of them are configured within the 192.168.1.0/24 range and the other halve is configured at 192.168.2.0/24.
This means I ...
0
votes
1answer
36 views
Find Routes not containing these subnets [closed]
Let's say I have 1000 ranges and I would like to make routes that doesn't match these ranges, anyone has any particular tips or tools to share beside doing math ?
Example :
I have these ranges
13....
2
votes
1answer
53 views
Why Classful addressing is not in use if we can subnet them?
So,
Let's think that organization needs 5000 IP addresses. Giving 20 C Class IP addresses will cause of adding 20 entries for ISP router. That's problem. We could give Class B IP address, but that ...
1
vote
1answer
51 views
Are subdomain and subnetting related concepts?
Recently while trying to grasp some basic networking concepts - I felt subdomain and subnetting are related concepts and wanted this group to confirm and add more insights on this.
I understand that ...
1
vote
1answer
69 views
Confusion about TCP/IP data flow in layers
I'm confused about how the data flows through the layers of the TCP/IP model, so I'll just tell what I think it happens (using an email example) and I'd appreciate if you can point my mistakes.
...
1
vote
0answers
22 views
How does the IP address lease process work? [closed]
Curiosity. When a Computer-A has just received an IP lease, for example 2 hours. And immediately it is turned off for about 30 minutes. And then new devices are connected. Can any of these new devices ...
0
votes
2answers
52 views
Why can some people use public ip address to access a server from an internal network with the client device within the internal network
As the title suggests. I find it mind breaking to think how network architecture can differ to allow/not allow using public IP address to access a server within internal network from within the ...
0
votes
0answers
12 views
How does loopback address check if TCP/IP stack is correctly working or not? [duplicate]
I have been reading about loopback addresses and most of the online material says that it is used for testing purposes and it validates if TCP/IP stack is installed and working correctly. How does ...
2
votes
2answers
52 views
Best way to Fast Reconnect TCP with dynamic IP
I am aware of TCP Fast Open, all though, I'm pretty sure it doesn't apply when the IP of the server changes dynamically. Getting the IP of the server quickly isn't the problem.
The problem is that I ...
2
votes
0answers
27 views
Packets lost with correct TCP sequence number. Is it possible?
I'm analysing some communication issues that we have between a server (SCADA) and remote terminal units (RTU) that we have in the field. The communications are IEC104 protocol which use TCP/IP.
The ...
1
vote
0answers
31 views
Why do corporate networks prefer application-level over network-level proxies? [closed]
I was recently using an application at work, which was unable to download needed files because proxy settings were not configured for the application. The company firewall blocks non-proxy connections....
4
votes
2answers
732 views
Confusion about data fragmentation/MTUs - why was it introduced in the first place?
I am currently studying networking as a part of my bachelors and I am a bit confused about why fragmentation/MTUs are necessary. In my lecture slides, it only says "Fragmenting if necessary" under the ...
0
votes
1answer
29 views
How does ISP know which port to open for incoming answer from a site requesting, since sites answer in different ports from ones we ask? [closed]
I'm wondering how does ISP open door for incoming answer from a requesting site since the answer doesn't come from the requesting door, and how to achieve my computer IP since it's behind ISP firewall,...
13
votes
4answers
3k views
Difference between :: and ::1
I am confused about following netstat output. There are two kind of local ports.
The first is:
[::]8100
The second is:
[::1]8100
I know that [::1] is a loopback address for IPv6. My question is:
...
1
vote
2answers
65 views
Question about the destination IP inside an IPv4 packet
I'm reading about link and network layers for the first time and I'm trying to put the pieces together to understand how they work together. My question may not have to do with the link layer but I'm ...
0
votes
0answers
9 views
Given a subnet mask, how can I determine which addresses can be assigned to public network hosts? [duplicate]
For example, I'm given a subnet mask of 255.255.255.248 and need to determine from a list -
16.70.118.63
134.178.18.56
200.47.224.159
68.111.178.93
192.168.16.87
217.37.10.192
- which addresses can be ...
0
votes
1answer
39 views
Header fields for IP fragments?
I am reading about computer networking and wanted to solve some related problems provided in the book. However, for this problem, no solution has been provided by the authors so I do not know my ...
0
votes
2answers
72 views
How computer “knows” how and what to respond to particulary ICMP messages
How a computer "knows" what to respond to particular ICMP messages?
As is known there are various ICMP messages that differ by type and / or code.
For example ICMP type 0 is "echo reply", type 13 /14 ...
31
votes
2answers
6k views
Why does the IPv6 header not include a checksum?
It is stated in Wikipedia that
an IPv6 header does not include a checksum.
What are the reasons that were behind this decision?
1
vote
0answers
60 views
Nexus OS IP SLA Object tracking
I have not configured IP SLA object tracking on nexus OS before and its looks a bit confusing. Can someone help me interpret the following configuration?
This example shows that object tracking is ...
0
votes
0answers
13 views
Building simple network configuration [duplicate]
For the below network configuration I need to propose an IP addresses, netmask and anything else obvious that I am possibly forgetting.
The network is built of four Computers, Router and a Switch. I ...
4
votes
3answers
2k views
Why can a host with a single NIC and on two networks have 2 IP adresses?
I understand that an IP adress refers to a NIC and not to a host, therefore a single host can have as many IP adresses as NICs.
But Tannenbaum says:
It really refers to a network interface, so if ...
7
votes
6answers
3k views
What happens with a ping when it enters a network? Is the router the one answering with a reply?
What happens with a ping when it enters a network? Does the router redirects it to one of the devices on the network, or it sends the reply itself?
Device a1 from network A, with public IP adress P1 ...
0
votes
0answers
13 views
Which mask to use for 1024 address size subnet [duplicate]
I am trying to identify if given IPs are from same 1024 SUBNET.
192.168.3.1
192.168.2.19
192.168.1.1
The part I got stuck is that SUBNET address size is 1024.
If I am sure, by checking IP addresses ...
1
vote
0answers
23 views
Is it possible to access 127.0.0.xxx in anyway [closed]
So I've been configuring my network at work. We've got a lot of devices from NAS servers to Dante AoIP devices.
While configuring some of my devices I managed to set the IP adress of one device to ...
0
votes
0answers
19 views
Give the 36th subnet for given network [duplicate]
Given network is: 148.47.0.0/16,
give the 36th subnet where you can uniquely address 54 hosts.
Where to start? Thanks in advance.
5
votes
3answers
2k views
Does NAT violate end to end argument?
Does NAT violate end to end argument?
What does end to end argument means in this context?
3
votes
2answers
97 views
Is an IP address necessary for a gateway?
When a IP sends something to another host outside the same subnet, it constructs a packet (L3) with the target IP being the IP of the target host, but the frame (L2) has the destination address = ...
1
vote
1answer
55 views
Routing protocol comparisons (with Linux) [closed]
I am doing some thesis about comparison of routing protocols, most notably how (how good, how fast) they react to changes in the underlying network. Not sure if this makes any sense, but too late to ...
0
votes
1answer
41 views
Transport layer segmentation and Ip layer fragmentation [duplicate]
From the OSI Model's point of view:
If we already have Ip fragmentation which happen due to the network limitation, why the transport layer provides the segmentation mechanism via TCP protocol?
why ...
1
vote
2answers
42 views
How TCP connections between origin and node servers over a BGP Anycast gets established?
Server A and B have the same IP address with anycast. Server B connects to the origin server that is very close to server A and very far away from server B, since server A is closer, the response will ...
0
votes
1answer
46 views
Remotely Connecting an IPv6 Computer to a IPv6 Private Web Server
I have a private web server at my office, and I want to access that server remotely at my house via IPv6.
My office has both IPv4 and IPv6 enabled, but my home has only IPv6.
IPv4 works, but I have ...
1
vote
2answers
167 views
How does a host know the ip addresses of other hosts on the same LAN?
So as the title say, how does a host know the ip addresses of other hosts on the same LAN? Is there a specific protocol for this? My first thought was that ARP could be used. But ARP seem to take an ...
1
vote
1answer
42 views
How to handle multicast address collisions?
Assume 2 multicast IP addresses IP1 and IP2 whose mac addresses are same due to collision
Let's say a host's NIC has joined multicast stream IP1 and another host on the original host's subnet joined ...
0
votes
1answer
202 views
Why is default gateway in routers configuration usually set as an IP address?
I mean why not just:
a MAC address? It should eliminate the need in ARP requests asking for gateway address. Also it should eliminate the need in changing IP addresses in settings when gateway IP is ...
0
votes
0answers
11 views
Why is the source / destination address ordering in IPv4 and IPv6 headers opposite of Ethernet source and destination MAC addresses? [duplicate]
Engineers always do things for a reason.
I've noticed that in Ethernet frames, the ordering is destination MAC address first, and then the source MAC address.
What's the reason for reversing the ...
0
votes
0answers
13 views
Split to four equal size subnets [duplicate]
Question;
Suppose an ISP owns the block of addresses of the form 128.119.40.64/25. Suppose it wants to create four subnets from this block, with each block having the same number of IP addresses. What ...
0
votes
0answers
15 views
About relation of ip adresses and number of hosts [duplicate]
Question is;
https://imgur.com/9nKqRgE
I am not sure about the answer but my thinking is that if there are 35 hosts then 2^x=>35 after that i find x is 6
it means 6 zero we have on subnet. and ...
0
votes
1answer
41 views
Enterprise network VS Industrial network [closed]
I would like to know the difference between the enterprise network and industrial Network.If someone has experience in industrial network, is he able to work in enterprise network?
0
votes
2answers
67 views
Is there a way to manage IP space with only a switch?
Is this scheme possible?
External provider = External provider of the internet
Generally speaking, is there a way to assign a public IP address individually for each server to be used when SFP+ port ...
0
votes
2answers
56 views
Same /24 IP prefix, same AS for 2 different locations, possible?
Let's say I have 2 locations:
1. the United States Datacenter
2. the Russian Federation Datacenter
I have 1 /24 Subnet with 1 AS. Both sites have a different ISP.
My target is to: allocate /24 for ...
-2
votes
2answers
105 views
How to discover a host when you don't know its mac, ip and subnet?
I have a network switch and I don't know its ip nor mac address nor even subnet. I need to get all this information.
Yes, there are tools like nmap and arp-scan, but the problem is they all need an ...
2
votes
1answer
73 views
Confusion about IANA “Protocol Numbers” registery
In the IANA registery for "Protocol Numbers", there listed 2 IP protocol versions: IPv4 at #4 and IPv6 at #41. Their "protocol" column says IPv[46] Encapsulation, and "reference" column points to 2 ...
