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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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2
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1answer
46 views

Why does TCP need segments if the network layer automatically breaks things up into fragments?

I'm trying to better understand the difference between IP fragments and TCP segments (https://www.shubhsblog.com/tech/difference-ip-fragmentation-tcp-segmentation.html) and there's one thing I'm not ...
0
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1answer
57 views

How to get a static IP address? [closed]

I need to get a static IP address to access to a service that only allows specific IP (I can manage the whitelist). The problem: my public IP is dynamic. I'd like to : be able to activate this ...
0
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0answers
13 views

IP block assignment [duplicate]

Let's say that an ISP manages the IP block 128.64.32.0/19, and assigns the block 128.64.32.0/22 to company A. Now, company B needs a block of IP addresses for 1234 hosts, immediately after the IP ...
0
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1answer
31 views

localhost vs local IP address: traffic flow [closed]

Let's say I have a server with IP address 192.168.0.1 that is running a network service (I don't think it is important what kind - let's say a webserver on port 80). If I am on the server itself and ...
2
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2answers
68 views

How to handle ICMP-in-IPv6 or ICMPv6-in-IPv4?

Since ICMP and ICMPv6 have different IP protocol numbers, it's technically possible for an IPv4 host to receive an ICMPv6 packet or for an IPv6 host to receive an ICMP packet. Is the host's behavior ...
4
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2answers
2k views

IP addresses from public IP block in my LAN

If I have NAT or PAT applied on edge router, Would it matter if I use IP addresses from public block in my LAN? And how?
1
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1answer
32 views

How to tell apart the type of the mask(subnet-supernet-net mask)

Say we have the the IP address 10.2.8.230/24 Anyone could say the following: It just represents a normal network:10.2.8.0/24 Or it is a subnet because normally this IP address is in the class A ...
1
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3answers
136 views

Is IP an abstraction

If packets "hop" from network device to network device across networks using MAC addresses, resolved by ARP, does this suggest that IP is essentially an abstraction? By abstraction, I mean, the ...
4
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2answers
19k views

Ip fragmentation and packet headers

I read somewhere that a fragmented ip packet can further be fragmented depending on the changes in the network. Now how is the packet reassembled at the router. Because the identification bit can be ...
0
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2answers
295 views

What does it mean when the last digits of an IP address change? [closed]

So in a case where I have an IP address, 162.158.68.xxx, what is happening when those values in xxx change? I ask because I'm looking at requests going through to my application's server and one of ...
0
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2answers
57 views

Addressing for a WAN, LAN and DMZ

I was wondering about the addressing for certain types of networking areas... I use 192.168.0.0 for a LAN network, 10.0.0.0 for a WAN and 172.16.0.0 for a DMZ. But I've been confused why a 10.0.0.0 ...
2
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1answer
103 views

Using an Ethernet cable and USB Ethernet adapter at the same time?

What would happen on using an Ethernet cable connected to one network and then plugging in another Ethernet cable but using an USB Ethernet adapter from a different network. Would it connect to both ...
1
vote
1answer
27 views

How do devices with static IP behave themselves when plugged to a new network? [closed]

I'm trying to understand how to determine if a device plugged to my PC with Ethernet cable has a static IP. What I'm trying to do is to sniff DHCP packets that it sends and by looking at DHCPDISCOVER ...
2
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2answers
57 views

ACL: Deny specific host not working

I'm trying to create an acl for use with a nat but I can't get the deny statements working. All hosts on a private network should be accessible, except from a server which should not be accessible ...
2
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2answers
788 views

ARP table is not updated with NMAP

Here is what I do and what happens : Let assume I have a device A with IP X.X.X.200 connected to the network I use Nmap to ping my local network, with the command "nmap --send-ip -sP 192.168.1.1/24" ...
0
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0answers
19 views

IP SLA Flow generator (udp-jitter)

I study IP SLA because i want to test my network for VoIP. I found an article who show a study of " Scalability of Layer 3 Tunneling Protocols: Case of Voice Traffic Over IP". "Based on this project ...
2
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5answers
28k views

How can 2 computers in different network communicate?

Suppose my friend and I are connected to the Internet via some local ISP (not necessarily same), which means we are on different networks, hence our computers have different private IP addresses. Is ...
5
votes
2answers
167 views

How to architect a globally distributed website, from an IP address perspective

I would like to have a website that is loaded fast from any point in the world. From my understanding, you need to take advantage of the data center "regions" at places like Google Cloud or AWS. That'...
2
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3answers
79 views

Is it possible that two servers were configured with the same ip under the same switch

I have two physical servers, their configuration as following: ServerI: IPADDR=10.1.1.5 NETMASk=255.255.255.0 ServerII: IPADDR=10.1.1.5 (Same IP) NETMASk=255.255.0.0 (different NETMASK) Because of ...
3
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1answer
93 views

Public and Private IPs

I wondered if someone could explain this to me. At work we have a firewall that connects to the Internet and has an external IP configured on it via DHCP. The firewall's WAN port connects to an ...
-1
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1answer
35 views

why can't we use the sequence number to distinguish them since every packet has a different sequence number? [closed]

It is a question from Networking stanford course. A server typically listens for TCP connections on a particular port (e.g. 80 for HTTP or 22 for SSH). Which fields can the server use to ...
0
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3answers
64 views

What IP address can't be the source address in a packet?

I heard that the destination address in a packet can't be 0.0.0.0. Is there any IP address (including special ones) which can't be the source address in a packet? Thanks.
0
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0answers
61 views

Which fields can the server use to distinguish packets for a particular client connection? [duplicate]

A server typically listens for TCP connections on a particular port (e.g. 80 for HTTP or 22 for SSH). Which fields can the server use to distinguish packets for a particular client connection?It is a ...
0
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0answers
20 views

Unable to calculate for subnet mask [duplicate]

My question is - To divide a class C network into a maximum of 14 subnets each capable of having up to 14 hosts, the subnet mask used should be .. what and how ?
0
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0answers
20 views

Questions about IP addresses [duplicate]

So, I have to research IP addresses, and there are a couple of things I don't quite understand. In my test there will be questions like 'Which of those IP-addresses is private' or 'which of those is a ...
12
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6answers
15k views

IPv4 Segment 100.64.0.0/10

I recently got to know that IP segment 100.64.0.0/10 has been reserved by IANA for 'Shared Address Space'. My question is: Can I use the IP Segment 100.64.0.0/10 as a private range in my network (...
2
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1answer
79 views

IHL(Internet Header Length) field is 4 bit long and specifies the header length in 32 bit words. What does it mean?

I am trying to understand IPv4. I cannot understand
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2answers
50 views

what does the flag and mtu means in here

Reading some logs from my system it states eth0: flags 4163 < up, broadcast, running, multicast> mtu I am not sure what is the meaning of the flag here down below I see eth1,2,3 has the same flag ...
7
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2answers
1k views

Why do IPv6 unique local addresses have to have a /48 prefix?

According to RFC 4193, unique local addresses will always have a prefix of FD00::/8.. but according to Wikipedia: The block fd00::/8 is defined for /48 prefixes, formed by setting the forty least-...
12
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3answers
1k views

Are the IPv6 address space and IPv4 address space completely disjoint?

Tanenbaum's Computer Networks says Finally, IPv4 addresses can be written as a pair of colons and an old dotted decimal number, for example: ::192.31.20.46 Does it mean the IPv4 address space ...
2
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1answer
49 views

What can an IP address be assigned to?

What can an IP address be assigned to? A network interface, which is what I thought originally. (I seem to hear a network interface can have multiple IP addresses assigned to it, and if it is true, ...
1
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1answer
116 views

Switch Configuration for Connecting LAN and WAN

Totally new on networking and on switches, so excuse me if I use some wrong terminology. Problem I have 1 computer and 7 instruments. I would like to form a network setup fulfilling the following ...
1
vote
1answer
29 views

Public IP addresses on cloud platforms [closed]

My question is about cloud platforms like AWS or Azure. Whenever we create an instance (VM or VPC), AWS allocates a set of public and private IPs for that instance. Now the number of user accounts (...
7
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2answers
2k views

What is IP squat space

I came across this article and I'm trying to understand what is going on here, I found some packets on my network containing 22.0.0.0/8 and 29.0.0.0/8 IP range and It's based on: https://en.wikipedia....
3
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1answer
156 views

Host IP address vs gateway IP address vs DHCP IP address

What is the difference between a host IP address, a gateway IP address, and a DHCP IP address when setting up networking devices? For example, when configuring a virtual network adapter for my VM, I ...
1
vote
2answers
39 views

How does a router know it's received an OLSR message?

So I'm working on my own routing protocol based on a alternative to IP, called ILNP, and I'm having trouble understanding how a router differentiates control packets and data packets for OLSR. The IP ...
3
votes
1answer
304 views

What happens if the IP MTU is smaller than the MSS?

Let's say i configure the MSS > IP MTU. Even if it doesn't make sense, would this be possible? Assuming i then try to send a file of the size of MSS or bigger, the network layer will receive the data ...
2
votes
2answers
592 views

OSI layer : Ethernet and IP address

I want to understand differences with hosts transmitting data to another host within a local LAN and hosts sending data to another host in a remote LAN. A book I was reading quoted this" "......
2
votes
1answer
54 views

IPv4 only host on a dual stack environment

I am looking into migrating to IPv6 at my company. Our plan is to dual-stack everything for now, however, we have a couple of local servers that are IPv4 capable only. The rest of our network will be ...
0
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1answer
82 views

OSI Model vs Network Model: Does It Matter Which One You Use?

The OSI (Open Systems Interconnection) model is comprised of the following layers: 7. Application Layer 6. Presentation Layer 5. Session Layer 4. Transport Layer 3. Network Layer 2. Data Link ...
2
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1answer
43 views

Where is the block which caused IPV4 client can not access IPV6 Server

I read many documents which are saying if you are in IPV4 network then you can not access IPV6 network, for example when I was at home I can not access some IPV6 website, such as:ipv6test.google.com. ...
5
votes
3answers
24k views

Setting subnet mask to 255.255.255.255

If I want just 1 device to be on the network, can I set the subnet mask to 255.255.255.255? For example, the consider the network card configuration IP 10.0.0.10 mask 255.255.255.255 ...
6
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2answers
3k views

Why maximum length of IP, TCP, UDP packet is not suit?

From many tutorials, I get follow knowledge(maybe I'm misunderstood) : maximum of an Ethernet packet is about 1500 bytes. maximum of an IP packet is about 65535 bytes. maximum of a UDP packet is ...
0
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0answers
21 views

Why maximum length of IP、TCP、UDP packet is not suit? [duplicate]

From many tutorials, I get follow knowledge(maybe I'm misunderstood) : maximum of an Ethernet packet is about 1500bytes. maximum of an IP packet is about 65535bytes. maximum of a UDP packet is 65515 ...
5
votes
1answer
40k views

How to divide network into subnets?

I've been trying to figure out how to divide a network number into particular subjects where one of them require a particular number of hosts. I have the Computer Networking: A Top Down Approach but ...
3
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1answer
53 views

ip dhcp class command

Here is a DHCP configuration that we have here: ip dhcp class range ip dhcp pool abc network 10.10.10.0 255.255.255.0 default-router ... class range address range 10.10.10.10 10.10.10.254 My ...
7
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4answers
2k views

Does every host on the LAN share the same ARP table, or do hosts keep them individually?

I'm just learning about ARP. I'm a little bit confused. My confusion is better explained in a scenario. Host A is communicating with Host B. Host A knows Host B's IP address, but not it's MAC address....
4
votes
1answer
446 views

Will the packet be dropped when the number of hops equals to default TTL?

From my understanding, the default TTL represents the maximum number of hops allowed such that the packet may reach the host. NTP Documentation Archive: ttl - This option is used only with ...
2
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2answers
185 views

How does/did an ISP serve so many people over IPv4

Whilst reading Tanenbaum - Computer Networks they talk about IP scarcity at the level of ISPs: IP addresses are scarce. An ISP might have a /16 address, giving it 65,534 usable host numbers. If it ...
7
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2answers
962 views

How do routers on the backbone avoid IP address conflicts?

As the title suggests, how do ISPs, and other networks connected to the backbone ensure that their host network address isn't already in use by another backbone node, as there is no controlling device ...