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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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 ...
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1answer
33 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 (...
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1answer
1k 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 ...
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2answers
3k 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
2k 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 ...
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2answers
66 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
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1answer
797 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
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1answer
68 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 ...
1
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1answer
188 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
76 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. ...
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2answers
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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 ...
3
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1answer
107 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 ...
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4answers
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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....
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2answers
1k 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 ...
4
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1answer
891 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 ...
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2answers
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What is the difference between 0.0.0.0 and a loopback IP address?

From the book Computer Network: The IP address 0.0.0.0, the lowest address, is used by hosts when they are being booted. It means ‘‘this network’’ or ‘‘this host.’’ ... All addresses of the ...
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3answers
473 views

Is an IP address assigned only to something with a Mac address?

From https://en.wikipedia.org/wiki/IP_address An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol ...
8
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1answer
1k views

Dealing with IP Spoofing

Border routers, which are routers that span two or more sub networks, can be configured to block packets from outside their administrative domain that have source addresses from inside that domain....
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4answers
2k views

How does a router know the destination mac?

so if I send a packet from a host to another from the same network we know the mac address of both the source and destination. However if the receiver is in a remote network the destination mac ...
2
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1answer
74 views

Can mobile devices take a global IPv6 address by means of only routing?

I'm probably asking this the wrong way, but here it is; I have a /48 block with static addresses for every device on the network. Everything is routed, no NAT, no tricks. My question is: on a mobile ...
3
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3answers
4k views

Is it possible to perform a Layer 2 (MAC address) traceroute?

I understand the difference between layer2 & layer3 and MAC & IP. I understand address resolution protocol, etc. But is there any way to do a traceroute that will show Layer 2 information? For ...
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1answer
62 views

Network IP questions [duplicate]

Suppose I have a network with IP address 192.168.10.1/16. This network can hold up to 65536 machines, from 192.168.0.0 up to 192.168.255.255 (65534 machines without the network ID and broadcast ...
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2answers
136 views

Why we need ARP when each device has its own IP address?

I don't really understand Address Resolution Protocol (ARP). Why we need ARP when each device has its own IP address?
3
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1answer
46 views

Why aren't we encrypting data on Network level instead of transport level when using e.g. HTTP [closed]

Why we are bothering to encrypt our data on a transport level, instead of just doing that on a network level with e.g. IPSec and get rid of the need to to that in upper layers. For example instead of ...
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0answers
78 views

Why are there only ~4 billion IP address available? [duplicate]

I am new to networking, so I apologize is this question is naive. I understand that 2^32 = ~4 billion. However, if you add in subnet masks, won't this number increase? For example, let's say you have ...
0
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1answer
93 views

Usable IP addresses and MPLS

I work at a company where I am partly responsible for IT, just because I'm semi technical and we're not big enough to warrant a dedicated role for someone else. I was asked to look into upgrading out ...
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1answer
78 views

Classifying IP address [duplicate]

I need to decide if the IP address 130.192.0.0 is a host or network address and which class it belongs to (A/B/C). I've read about the different ranges that the different classes have of IP ...
2
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2answers
3k views

Cisco 899G-LTE Cellular 0 interface in spoofing mode

I have a problem. After I've reseted my router configuration it doesn't get IP from LTE SIM card. Seems like my celullar0 interface is in spoofing mode. > Router#show interfaces cellular 0 ...
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2answers
640 views

Is IP address starting with 115. public or private?

I have one device with ip address 115.124.114.111. I want to know if IP address starting with 115. public or private?
2
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1answer
45 views

Exclude 10.63.128.0 10.63.255.255 or 10.63.128.0/17 range from 10.0.0.0/10

Please help to suggest a method to exclude IP range 10.63.128.0 10.63.255.255 from 10.0.0.0/10. I have a access list 3100 to filter the traffic with rule 10 10.0.0.0 0.63.255.255 and now I have to ...
0
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1answer
369 views

Finding the IP address of a Cisco 3750G

Hello i have a Cisco 3750G switch and i need to find the IP address and I dont have a serial cable, so I need the IP address to login into the web-interface. Does it need to be connected to a network? ...
2
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2answers
5k views

0.0.0.0/32 Special-Use address

I was wondering what is the role of this special-use address. The similar 0.0.0.0/8 represents a host with no IP assigned,but it's not the same with the 0.0.0.0/32 address What is the difference?
3
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2answers
2k views

Private IP vs MAC

What I know is that when we connect to another IP, our Public IP gets shared to the outside world, and when they address us they use our Public IP (gateway), and then the gateway directs the ...
3
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2answers
439 views

Subnetting-Supernetting and Classful-Classless routing

1) Subnetting and Supernetting can both be done for private and public IP addresses? 2) Classful addresses weren't successful because of IP wasting, and that is why the 'network mask' was invented, ...
4
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2answers
1k views

How does a TCP segment fit into a smaller IP packet?

The IP protocol can handle fragmentation and it includes the fragmentation offset and identifier. I know this comes into play when your IP packet is too big for some specific network or link where the ...
22
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6answers
6k views

What stops someone from configuring their network with IP addresses they do not own?

Here's the scenario. I was picturing a university that bought a range of IP addresses. I think their network would still be connected to an ISP (right?), but they'd have freedom to configure stuff the ...
0
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1answer
73 views

IPv6 variables or other methods of shortening

From the dawn of when I heard about IPv6 many years ago, to my continued hesitance to make good use of it in today's world where it's eventually going to become necessary... my biggest issue I think ...
4
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2answers
2k views

What does it mean to lease an IPv4 block?

When you lease an IPv4 block, what do you actually get? How do you get access to the IP addresses? Is there any special equipment required or is it as simple as renting a server?
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8answers
9k views

Why are IP addresses given to each interface and not device? What would the implications of that be?

Why do we need to give IP addresses to each interface? Wouldn't giving one to each device be enough?
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1answer
72 views

Find Major network vslm

Im a bit lost with this question. In order to get proceed with the vslm i need to find the Major network of this subnet 121.118.40.0 /19. For me the major network is 121.118.32.0/19, but when I run ...
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1answer
104 views

Finding the network address for given host IP?

Answer provides the procedure to find the network address when a packet with destination IP(198.51.100.223/21) is reached at a router. But a network packet has the destination IP 198.51.100.223 in ...
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2answers
1k views

How are websites accessed without port numbers?

I am confused on how requests to websites are received. If I type in 172.217.5.110 to my browser, google.com sends me its home page. I didn't have to specify the port number. How does that work? I ...
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1answer
231 views

Why CIDR block is assigned to subnet? [duplicate]

If VPC is assigned CIDR block 172.31.0.0/16, then I can create sub-nets within VPC, following this procedure: 172 . 31 . 0 . 0 255 . ...
0
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1answer
2k views

IP Addressing-Why All zero(0) and all one(1) in subnet id bits are reserved?

I'm studying about class less inter domain routing. I've come to know that all zeroes (0) in host id bits refers to subnet address and all ones (1) in host id bits refers to broadcast address. So, ...
6
votes
4answers
1k views

OSI layer of Neighbor Discovery Protocol

NDP operates using ICMPv6 and, even though ICMPv6 messages are encapsulated in payload field of IPv6 datagram, ICMPv6 and ICMP are usually considered as network layer protocols. At least, on Wikipedia ...
0
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1answer
57 views

Daisy chaining IOT devices without switches? [closed]

I have multiple IoT board with two network interface in each device. I want to connect them in a daisy chain without help of switch. The eth1 of first device will be connected to eth0 of second device,...
3
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1answer
88 views

Global Unicast in IPv6 Neighbor Discovery

I have a very small pcap file in which Neighbor Discovery is performed for Global Unicast Addresses. That is, IPv6 addresses of both neighbors as I can see in Wireshark start from 2001:. Both IPv6 ...
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2answers
860 views

Link Local Address using in NDP (IPv6)

How is using of link local address in NDP. We can discover neighbor by using global address. So why we need link local address in NDP?
0
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1answer
144 views

How does a router forward datagrams from the internet to an interface of a private network?

As I have seen in How does a router know to which PC in a network to send a response from a server? if I haven't misunderstood it, if an interface in a private network sends a Datagram to the outside ...
7
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1answer
390 views

Is the first address of the subnet a valid configurable address in case of IPv4 and IPv6 point to point networks?

Am I correct, that first address of the subnet is a valid addresses to configure in hosts/routers in case of IPv4 and IPv6 point to point networks? For example, in case of 192.0.2.0/31 one of the ...

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