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.
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What is IP transit?
I came across "IP transit" as a product. I tried reading up on it but do not understand it. Can anyone explain in simple terms what IP transit is?
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Fortigate IPsec site-to-site routing issue
Site A needs IPsec with site B.
Site A networks 192.168.20.0/24 and 192.168.50.0/24 need to reach Site B network 192.168.1.0/24. And the other way around as well.
The problem is that Site A has a ...
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IP Assignment for applying ACL on Cisco Nexus3500 C3548P-10GX Chassis
Context
Following are the details of the layer-3 switch
cisco Nexus3500 C3548P-10GX Chassis
Intel(R) Core(TM) i3- CPU @ 2.50GHz with 16396528 kB of memory.
Processor Board ID FOC25244X6C
We have ...
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Subneting in IPv4 Networking [duplicate]
How do I divide 198.162.17.0 /24 into 2 subnets?
Please show your workings to enable me understand it properly
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Unable to Assign IP Address to FastEthernet Interface on Cisco Router
I am currently working on some Cisco Packet Tracers project and I have run into some problems when trying to configure an Ip address to a FastEthernet Port.
For more context I am using a 2901 Router ...
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What stops you from use private IPs in Internet?
I know there are some IP addresses ranges called "Private IPs" which are used in private networks and are not supposed to be used in public networks like Internet. I also read another ...
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MTU - proactively setting to lower than 1500 on endpoints to prevent tunnel issues
With machines being deployed to various locations where internet is controlled by others, sometimes there can be one or two tunnels which necessitates using lower MTU to avoid communication issues, ...
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Why is MSS important? Why can't we just rely on the MTU?
Note: I understand both what MTU and MSS do so I am not asking about their function here. I understand that when a TCP connection is being established, the MSS is exchanged and it dictates the maximum ...
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Where is netmask information stored?
I have some practice with networks, but not much theory. I saw in this question that netmask is not stored in the TCP/IP packet.
However, from my experience if I:
connect machine A to port 1 of ...
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Why is IPsec transport mode "vulnerable" for not having integrity of variable fields? Why is this so important?
With IPsec transport mode we CAN'T have integrity of variable fields (eg TTL and checksum). Why is it a problem? Is it? What could be the attack?
I think TTL expire or checksum modification (so both ...
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Could address be omitted from packet in IPv4 if router is sending to / from that address?
Imagine an IPv4 packet routed like this:
A -> Router1 -> Router2 -> B
When constructing a packet per the structure, it seems A will have to include both source address (A) and destination ...
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In IPv4 Fragmentation, should the first block be necessarily the closest smaller multiple to 8
Is it mentioned in any RFC's that when one is splitting a Datagram into fragments, the bytes in the first fragment should be "the closest multiple of 8" or is it just a standard ...
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How localhost and its opposite 0.0.0.0 works
Here I am running an application on a computer, host=localhost, the application runs on localhost:5000, or 127.0.0.1:5000.
When the computer accesses 127.0.0.0/8, or 127.0.0.0 subnet mask 255.0.0.0, ...
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What exactly does the term "main network" mean in subnetting?
In the computer networks course, we solve subnetting questions together with the teacher. There is a term we call the "main network". As far as I understand, we fill in this according to ...
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GSM and LTE-M connection with SIM7070G for MQTT data transmission
I am working on a tracker project using the SIM7070G modem from SIMCOM. The objective is to maximize the connection by working with both LTE-M and GSM, aiming to send location data via MQTT.
I have ...
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The Reasoning Behind TCP and UDP Multiplexing Tuple
I understand that TCP and UDP are multiplexed protocols, and the multiplexing key in them is the (sender.ip, sender.port, receiver.ip, receiver.port) tuple. I understand the reasoning behind sender.ip,...
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Do destination hosts decrement the TTL?
I was trying to understand more about traceroute when I stumbled upon this site and I have a question about this diagram:
As you can see in the diagram, the destination host S1 receives a packet ...
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What TTL value should i use to make sure the packet never leaves the broadcast domain
If i put the TTL as 0, will it never leave my broadcast domain? If I wanna send something to someone in my broadcast domain, can the ttl be 0 or will it still be dropped? Or should it be 1?
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Too many mac addresses in a switch - Cisco Packet Tracer
The image of a network im refering to is above. In Cisco Packet Tracer after having used a command ping 192.168.1.3 from pc1 to pc3, when I check mac addresses in both SW1 and SW2 using show mac ...
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Why can't we use large-scale NAT system with thousands of private IP addresses assigned to a single public IP
Instead of assigning everyone an individual public IP address, could we use a very strong NAT system with thousands of private IPs behind a single public IP? This could reduce public IP demand and ...
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End to end delay over N link including the (simplified) propagation delay
It is well know (see this question) and easily verifiable that end-to-end delay in case of trasmission of P packets of size L over N equal links (same transmission rate R) with zero propagation delay ...
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Is a private network the same concept as a network which uses private IP addresses inside it?
Kurose's TopDown Network book says:
8.7.1 IPsec and Virtual Private Networks (VPNs)
An institution that extends over multiple geographical regions often
desires its own IP network, so that its hosts ...
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How can I have multiple servers and IPs if I only have 1 ip with gigabit connection?
I have 1 gigabit connection with static public IP address...
Without depending on my local ISPs colaboration, is it possible to buy IPs from an online service and route each individual IP to my local ...
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IP fragmentation and PMTUD
I have 2 questions.
1) According to a lot of sources, when IP packets gets fragmented, in this case, lets take icmp, the icmp header is present only in the first packet.
But I have observed on some ...
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Would a /24 public ip range typically be from the same country?
Would a /24 public ip range typically be from the same country? This to reduce the amount of ipstack requests, checking from what country an IP is. (due to bot requests)
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Why the length of IP address is fixed? [duplicate]
Is there technically reason for the fact that the length of IP address need be fixed? Now IPv4 address is 32 bits and IPv6 128 bits.
If IP address doesn't need fixed length, we would can structure IPs ...
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What is hiearchy of IP addresses? [duplicate]
What is structure/hiearchy of IP addresses?
I mean, is mandatory that IP address e.g. 216.9.10.0 is subnet of 216.9.0.0? Of course many times that is the case and IMO it would be logical, but I have ...
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The TTL and packet drop [duplicate]
I would just like to verify one thing. When a router receives a packet with a TTL of 1, the router can still process and accept it if its destined for itself, correct? Because for example, eBGP ...
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ISP ARP tables and routing [closed]
So I'm Network+ certified and have a beginners understanding of how network communication works, my head starts to split a bit though when I think about how the information is actually communicated ...
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Can two separate computers connect over 127.X.X.X IP range? [duplicate]
Is it possible to set two computers (each have one lan interface) to communicate over 127.X.X.X IP range (e.g. one PC 127.15.0.1 and the other 127.15.0.2)
+-----------+127.15.0.1+-----------+
| MyPC ...
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Layer 3 Switch IP Problem on Packet Tracer
I set up a network. It contains vlans. I assigned devices ip addresses from different subnets. I have 2 layer 3 switches to communicate them. I assigned switches ip addresses from different subnet. I ...
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Simple question about NAT [duplicate]
So I am learning about NAT. I understand that it changes IP from public>private and vice versa. From my understanding, when a packet or info gets sent to the public ip towards the private ip, ...
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Basic Networking - IP address
guys, I am currently going through basic networking concepts... There is this piece of information:
'Briefly, an IP address (or Internet Protocol) address can be used as a way of identifying a host on ...
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No access to internet via DHCP, but works with manual IPs
My DHCP server was giving out IPs in the range 10.0.0.1/24, but I ran out of usable IPs, so I changed the subnet to 10.0.1/21 to have more available addresses, however I am now having a weird problem:
...
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Advertising IP prefixes to the internet using BGP
I am studying BGP at the moment.
From what I've learned, in order to participate in routing on the internet and use BGP, we need to register a public provider-independent IP address block and a public ...
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RIP v2 Network Command
I am comparing the Boson ExSim Lab to the Neil Anderson's Lab on RIP.
On one of the labs on Boson ExSim, it asks to configure RIP on the routers, all of which are on some form of a 192.168..0.0/24 ...
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What does "Configure kernels to not follow the RFC 5681 SHOULD" mean?
Netflix documentary The Playlist about Spotify, they present one of the technical breakthroughs that they created their own TCP implementation to reduce the latency from first click to playing the ...
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How to prevent a user from using YouTube while connected to my network [closed]
i need to restrick specific user from using youtube and other socialmedia during job time
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Understanding IPv4 model of operation
I'm new to networking and reading RFC791 about IP protocol specification and got some question regarding the paragraph 2.2 Model of Operation. Here is what is discribed:
The internet module prepares a ...
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IP and Ethernet endianness
I'm completely new to the topic, I've read that Ethernet sends Bytes in a Big-Endian way, but that bits are sent with Little-Endian. I've also read that IPv4 uses Big_endian order. So my question is, ...
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Recognizing the next protocol in MPLS header
How can I know what is the next protocol in MPLS header?
I do know that MPLS header does not provide any information about the next protocol,
But I somehow need to know how to recognize it, as I am ...
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does routers use MAC addresses to map request/response?
we know that Local machines use private ip address inside a company and share a single public ip address when communicate to the outside world, so does routers use MAC addresses to map request/...
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Why Linux answers ARP requests for IPs that belong to different network interfaces? [closed]
My machine has a physical network interface (eno1) and a bunch of virtual network interfaces (e.g. tap0). Each interface has its own IP and their subnets do not overlap.
I noticed that if I perform an ...
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How did ATM switches that were implemented in a core of IP network improve QoS and higher data rate?
How can ATM switch improve Quality of service and data rate just by incorporating them into the core of IP network? What was used in the sore of IP networks before ATM switches and what is used today ...
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How does subnetting solve the problem of IPv4 address shortage?
Reading articles on the web, they all say that "subnetting solves the problem of IPv4 address shortage by dividing a large physical network into multiple smaller networks". I do not ...
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Why does a PIM DM assert loser reply with a prune?
In PIM Dense Mode, why does an Assert loser send a Prune message to the winner? What is the actual motivation for this?
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Not able to ping device with different subnet on gateway and ip adress
I am trying to ping a device with IP 192.168.0.200, subnet mask 255.255.255.0. It is configured with gateway adress 192.168.1.1.
Is it because the gateway subnet, and ip adress subnet is different i ...
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What are the triggers for PIM-DM prune and assert messages?
There are articles explaining the PIM-DM mechanics, and they only confused me. Considering the most common topology, that of three routers, connected to each other like a triangle as such:
R1 -- R2
\ ...
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Hop 1 of the traceroute to Internet is not the gateway [closed]
I'm assigned to a public IP address from my organization. Here is my default route:
IP: 45.150.164.x
Gateway: 45.150.164.1
netmask: 255.255.255.0
And here is the result of traceroute 8.8.8.8 from my ...
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Sharing same IP address inside LAN? [duplicate]
Q: if 2 devices A and B share same ip address in LAN, can device A retrive all messages whose destination is device B?
I think this depends on how the LAN is configured.
If it's wireless then device A ...
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