Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

0
votes
0answers
12 views

Why are ARP entries on my computer missing when hosts leave the LAN? [on hold]

From my understanding, an ARP entry occurs when you communicate with a device on your LAN. This ARP entry resolves the I.P. address and caches it for your host the next time it needs to communicate ...
-3
votes
0answers
25 views

Determine if an IP address is in an IP Address Range [on hold]

I have no idea about IP addresses and am looking for advices. I would like to know that if I have an IP address, how can I work out precisely if that IP address is in a given IP address range?
3
votes
1answer
34 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 ...
6
votes
4answers
1k 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....
0
votes
0answers
20 views

Subnetting with dhcp for a school project [closed]

i'm working on a network project proposal as homework, the goal is to design, at a high level, a network for a local publisher of a small province that wants to expand his business (with a web page ...
6
votes
2answers
871 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 ...
0
votes
0answers
9 views

IPIP channel strange behavior and bonus question [closed]

I have two networks connected by IPIP channel. DNS server for BOTH networks is accessible on Network B Network A has large number of DHCP clients. Those clients are using DNS server (which is ...
0
votes
0answers
28 views

How to make a cient-server communication without Domain Name [closed]

In the context of a web application including clients and a web service (server), i want to have a client-server HTTP communication over internet. I'm aware that the IP adress is dynamic and may ...
0
votes
0answers
39 views

What will happen if an IPv4 packet’s total length field exceeds the packet’s actual length? [closed]

If a router or a host receives a packet, the value of "total length" field is larger than the packet's actual length, what will the router (or the host) do? Below is a sample, I edited a packet, then ...
4
votes
1answer
312 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 ...
18
votes
2answers
5k views

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 ...
0
votes
3answers
69 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 ...
-1
votes
0answers
15 views

How to Create Subnet hosts and figure out how many unused Host IP address [duplicate]

5.1) You are given the address block 192.168.22.0/24. Your task is to a create a subnet for at least 10 hosts using IP subnetting. For this subnet determine the size of subnet, subnet ip address, ...
6
votes
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....
2
votes
2answers
51 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
votes
1answer
38 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
votes
3answers
67 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 ...
-1
votes
1answer
41 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 ...
0
votes
2answers
72 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?
2
votes
1answer
37 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 ...
0
votes
0answers
18 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
votes
1answer
35 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 ...
-1
votes
1answer
51 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
votes
2answers
169 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 ...
-1
votes
2answers
107 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?
1
vote
1answer
39 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
votes
1answer
42 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? ...
0
votes
0answers
17 views

DHCP Broadcast messages [duplicate]

Why are there so many DHCP broadcast messages while trying to give a computer some network settings? 2.Last,when can these broadcasts be avoided and how are DHCP relay agents related to the whole ...
1
vote
2answers
313 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?
0
votes
1answer
39 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 ...
2
votes
2answers
145 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, ...
3
votes
2answers
83 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 ...
20
votes
6answers
5k 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 they'd still be inside a ISP (right?), but they'd have freedom to configure stuff the way they wanted. ...
0
votes
1answer
44 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 ...
11
votes
8answers
5k 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?
-1
votes
1answer
34 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 ...
1
vote
1answer
43 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 ...
-1
votes
1answer
55 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 ...
-1
votes
1answer
23 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
votes
1answer
106 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 zeros(0) in host id bits refers to subnet address and all ones(1) in host id bits refers to broad cast address. So, ...
6
votes
4answers
703 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
votes
1answer
17 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,...
2
votes
1answer
23 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 ...
1
vote
2answers
71 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
votes
1answer
32 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
votes
1answer
241 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 ...
1
vote
1answer
28 views

Is it possible to implement virtual network based on MAC in IP instead of MAC in UDP?

We know that flannel use MAC in UDP to create a overlay network. My question is: UDP header only provides an extra port number fields, let's suppose that one physical machine only run one flanneld ...
2
votes
2answers
145 views

IPv6 can't ping host when static route configured with exit interface

I have the following topology (using IPv6) interfaces: I have the following static routes configured on it: R1#sh ipv6 route static IPv6 Routing Table - default - 9 entries Codes: C - Connected, L -...
1
vote
1answer
32 views

I am trying to set up aDHCP server in a VLAN for practical of networking with Linux

I am a Linux user requesting advice about setting up a DHCP with a VLAN based on offices on one floor for the practical purpose. Is this good enough for implementing a VLAN structure with a DHCP ...
3
votes
3answers
55 views

Native IPv6 load balancing

We have two software gateways (on Linux) for IPv6 that take fullviews from ISPs and announce our AS. And several nodes connected to Internet via the gateways. Something like at picture: And we ...