Questions tagged [ipv4]
For questions about Internet Protocol version 4 (IPv4); as specified in RFC791.
795
questions
0
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0answers
15 views
Do any subnets “Network ID” AKA “Network Address” always have an even number as the last octet? [duplicate]
Should a subnet have a "Network ID" AKA "Network Address" (eg: the first address, which is always unusable, and is the boundary between the previous subnet and the current subnet) ...
0
votes
1answer
34 views
Are routers doing NATP possibly run out of ports?
NATP helps each connection on the client device gain a "temporary identity" on the internet, by maintaining a one-to-one relationship between its local ip-port to a WAN ip-port. The binding ...
-1
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0answers
12 views
IP Address mathematics-: How to add 120.89.96.129+399? [duplicate]
I am doing subnetting numericals to get my first job of network technician and I stumbled upon this math.
I know the range of IP is upto 255. But I am not exactly sure how to add value to IP address ...
-2
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0answers
36 views
How to solve this IPV4 subnetting numerical? [duplicate]
Design IPV4 sub network for an organization having 10,56,78,29 and 14 computers in each department. Use 192.168.10.0/24 to distribute the network. Write network address, valid hosts range, used host ...
-1
votes
1answer
20 views
how does a host learn about other hosts IP addresses connected on the same subnet? [duplicate]
My question is similar to one posted [here][1]
But answers are not understandable to me. How can a host (say my laptop) learn about IP addresses of other devices (say my phone) on the same subnet. ...
4
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3answers
339 views
Questions about NAT
So i just started learning about NAT and networking in general. As powerful as this technology may seem, it was specifically made for reducing the amount of IPV4 addresses used throughout the internet,...
4
votes
1answer
92 views
What are the negative impacts of using non RFC1918 addresses on a private network?
I work for a company overseeing network design of a large industrial system. For our purposes, it's a backbone network that other stakeholders have their own L3VPNs defined on. It is a network with ...
2
votes
1answer
22 views
Assigning static IP address from the DHCP pool range on Cisco 800 series
What happens if I assign a static IP address to a device in a LAN where there is an active DHCP server and the address falls within the configured DHCP pool and DHCP server is Cisco 800 Series?
Most ...
1
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1answer
63 views
I cant ping across Lan?
Current configuration : 2695 bytes
!
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
service password-encryption
!
hostname ...
0
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2answers
40 views
How does RIRs actually ensure IP ranges ownership
I'm currently learning about CIDR, subnets and IPv4 classes.
I understood that IPv4 classes were used to route traffic in the beginning but nowadays we use "dynamic" subnet masks with the ...
1
vote
1answer
63 views
How does a device receive default gateway IP address?
When and how does a device get information about default gateway in LAN? I know you can define default gateway statically, but which protocol is used when it is not statically defined? Is it from ...
0
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0answers
12 views
Divide IPv4 network into subnets in a SPECIFIC order [duplicate]
My private addresses start at 10.10.0.0/16. I must make 2 subnets with 120 and 450 starting with the 120 one and not leaving any unnecessarily unused addresses.
Let me remark, it's IMPERATIVE that the ...
0
votes
2answers
58 views
Are the IPv4 datagram addresses the corresponding public addresses, or the private addresses?
Inside the IPv4 datagram, there are the source and destination IP addresses. The first indicates the IPv4 of the source host, and the second indicates the IPv4 of the destination host.
Are these ...
-1
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2answers
91 views
Why do we need private IP address range?
When it comes to local networks, you have the freedom to use any IP address you want for your network since it doesn't need to communicate on the internet with other devices. However, the RFC ...
0
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0answers
7 views
A question from an online subnetting quiz [duplicate]
Does anyone know the last usable host IP address for the 172.45.120.0/23 network? And an explanation of how you got the answer? It's a multiple choice question on an online subnetting quiz. I'm ...
0
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1answer
31 views
Why is my assignment asking me use 172.16.0.0 private addressing and IPv4 sub netted Class C address Scheme?
I am doing a project for Cybersecurity and trying to build a college campus network. The complete instructions read:
LAN infrastructure layouts for all campuses.
• Represent multiple building/...
15
votes
3answers
3k views
Why does one say IP fragmentation is bad and to be avoided when in reality data always needs to be fragmented for MTU compatibility?
Why does one say fragmentation is bad and must be avoided due to performance issues when in reality fragmentation intrinsically occurs within the communication ?
Example:
User1 wants to send 100 000 ...
0
votes
1answer
44 views
How routers route packets to a specific network
As I understand it, routers route packets to a specific network based on network id and of course the network id must be unique on the Internet, now the question is: maybe there are billions of ...
1
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2answers
30 views
rules regarding IPV4 fragments and piecing them together
I'm rolling off my own TCP/IP stack for DOS and I have a question on IPV4 packets.
Assuming that a client sends multiple IPV4 fragments, I would predict the MF flag would be set for every fragment ...
0
votes
1answer
49 views
How is the subnet mask detected over the internet with CIDR (classless inter domain routing)?
Lets say there are two public IP addresses. One is 21.120.12.8/16 and the other is 21.120.12.8/8, they are different network IDs but when used over the internet how are they both differentiated? Or is ...
0
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0answers
12 views
Extract Palo Alto ACC stats in text format
I have a Palo Alto p220 firewall, which acts as a virtual router at the same time. I would like to get the traffic data (download/upload in bytes per IP) in a format, which I could then parse on my ...
-1
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1answer
39 views
What is the maximum number of networks in IPv4?
From my understanding, in IPv4 addressing, the first 2 octets identify the network, meaning 2^16 networks can exist. But that doesn't seem even closly enough as the population in even USA is above 300 ...
1
vote
2answers
60 views
Basic conceptual questions about network interfaces
I have some basic questions as I am trying to understand the concept of network interfaces a bit better.
Is network interface same as network interface card (NIC)? If not, what's the difference.
What ...
5
votes
2answers
757 views
Can a client-side outbound TCP port be reused concurrently for multiple destinations?
Can a client-side outbound TCP port be reused concurrently for multiple destinations?
If it's possible, this would let NAT gateways milk an IP Address much more, and make it practically impossible to ...
0
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0answers
29 views
ECT Marked ICMP Responses
For ongoing research I'm conducting, I'm measuring the modification of ECT fields of the IPv[46] header. To do this I'm relying on ICMP quotations to inspect what packets 'look like' as they traverse ...
0
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0answers
10 views
Into how many subnets can you split this address range up at most? [duplicate]
Let's say there is address range given: 124.33.66.0/23.
Into how many subnets can this address range be splitted up at most if each of these subnets includes at least 5 devices?
I don't know where to ...
0
votes
0answers
18 views
Why did we not run out of IPv4 adresses yet? [duplicate]
I know how IP addresses work and I also understand the reasons why there is a natural limit to those addresses, as well as the solution to that problem. Officially, we have ran out of IPv4 addresses ...
0
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0answers
12 views
What is the use of a host mask/ wildcard with respect to subnetting and ranges? [duplicate]
Taking the example of 10.0.0.0/20, that means my range is 10.0.0.0 to 10.0.15.255 I got that range because I know that the wild card is 0.0.15.255 and I just add it with the beginning address 10.0.0....
1
vote
1answer
130 views
Why does this ip address give me an error “must be valid ipv4 cidr”?
If I set up an AWS VPC with CIDR of 10.0.0.0/20 then the range is 10.0.0.0 to 10.0.15.255
I make a subnet now. Why does 10.0.15.15/28 give an error. Isn't it's range 10.0.15.15 to 10.0.15.30 which is ...
1
vote
0answers
22 views
Why did the IANA specifically choose these ranges for the the private IP address space? [closed]
10.0.0.0/8 IP addresses: 10.0.0.0 – 10.255.255.255
172.16.0.0/12 IP addresses: 172.16.0.0 – 172.31.255.255
192.168.0.0/16 IP addresses: 192.168.0.0 – 192.168.255.255
Is there any reason behind ...
0
votes
3answers
62 views
Routing IPs through another ASN
So currently we have a few /24 ranges that we are looking to use on an upcoming project, we also have an ip circuit with a tier-1 ISP and bgp peering is established.
Me and my business partner know ...
0
votes
1answer
208 views
Why DNS services Like google public DNS and Cloudflare 1.1.1.1 has ipv6 versions?
I understand the need for ipv6 as we ran out of ipv4 but dns resolvers like google and cloudflare already have ipv4 addresses for resolving dns and i don't see compatibility as a reason either because ...
0
votes
1answer
135 views
Ping to default gateway failing
I am trying to ping to a default gateway which i have configured as 171.2.0.1 but somehow the ping is failing . I am new to network domain so i have less idea about it . Any help is appreciated .This ...
0
votes
1answer
49 views
Need a little clarification with NAT and IPv6
I understand NAT exists to not exhaust all the ipv4 addresses so there is no need for it with ipv6. So with ipv6 having an unimaginable amount of addresses, will every device have its own public ...
0
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0answers
8 views
Confused in what maximum number of hosts and maximum number of subnets mean [duplicate]
Given a 172.12.0.0 /16 to be subnetted to appropriate networks. Branch 1 has 80 hosts, Branch 2 has 31 hosts and Branch 3 has 75 hosts.
I've already made a subnet table based on these using VLSM:
...
0
votes
1answer
68 views
Loopback interfaces subnets [closed]
Assuming that loopback interface is always alone in its network, what are the practical reasons to have IPv4 subnet prefix shorter than /32 for these interfaces?
Moreover, why according to various ...
2
votes
3answers
79 views
Routing with private addresses
Let's say that we have a private network, with private addresses and a NAT enabled router at the end. If the router is misconfigured and routes traffic to the global internet, keeping as source ...
1
vote
3answers
89 views
Combining NAT an tunneling
I was reading a text and a doubt came to mind. Suppose there is an interface in a router that implements NAT. That same interface is the extreme of a tunnel. If I was to send a message through said ...
1
vote
1answer
100 views
“SWIP” Equivalent for RIPE?
With ARIN, I was familiar with using "SWIP" for IP blocks via an ORG and a POC.
With RIPE, however, it seems that it's different.
I have access to a RIPE account where I can make the changes,...
2
votes
3answers
79 views
One client: static IP vs Static lease DHCP vs. DHCP limited range to 1 slot
I want to attach one client (only 1 maximum) to network router ethernet port. I want to always know the client's IP address, for my port forwarding settings. Using DHCP with range the client IP could ...
0
votes
2answers
120 views
Is the routing table used when sending IP packets to a host on the same LAN in ipv4?
I am having trouble understanding the steps in order to send an ip packet to another host on the same LAN. Most sources online that I have read and people I have talked to say that the host uses the ...
1
vote
1answer
33 views
By General Convention if we say the Frame size is 1KB do we take it as a 2^10 Bytes or 10^3 Bytes
In my academic we generally follow 2^10 Byte approach , I m really at loss is it by convention only at my college or something which is accepted widely
0
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2answers
516 views
Is not 192.168.88.1 (192.168.*.*) always an “internal” IP address?
I had some headache with a proxy setup which I couldn't figure out. Turns out that only "127.0.0.1" and "localhost" were recognized as "localhost" or "internal" ...
0
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1answer
5k views
How to find the first and last address in the FIRST AND LAST SUBNET [duplicate]
So there's a problem that literally stress me out every time I look at it. It's like I almost understand it until I get to knowing how to find the first and last host in the LAST address (last subnet)....
0
votes
1answer
34 views
Are there broadcast/collision domains on non-Ethernet networks?
What if we have routers or hosts connected via ATM, Frame Relay, or SONET; that is, what if we have IP over SONET, IP over ATM, IP over Frame Relay, etc., do we still have broadcast domains and ...
2
votes
1answer
155 views
IPv4 and UDP/TCP packets inside of ICMP packet?
A week ago, after opening wireshark, i was surprised by seing a storm of ICMP packets from different IP addresses. While deep analysing of thoses packets, i noticed that those ICMP packets contains ...
-1
votes
1answer
48 views
IPv4 and IPv6 Source Address field
Both the IPv4 and IPv6 headers contain the source address field.
What are the reasons for including this field?
Is it for to trace which who sent this packet if it get's lost?
0
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0answers
12 views
How does the IPv4 Total Header Length field & Fragmentation work together? [duplicate]
I recently learnt that the maximum value of the IPv4 Total Header Length field is 65,535 which equals approx. 65.5KB. To my understanding, it is different from the IHL field as it includes the ...
0
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0answers
11 views
Why does sub-netting not give us more addresses? [duplicate]
Sorry if this is dumb, but I am very knew to learning about networks.
Here is my reasoning?
Let's take the address, 24.50.12.4
if we subnet it with /16 then the network address is 24.50 + host is 0.0....
0
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0answers
9 views
How to find Best Fit Mask [duplicate]
How does i find the best fit netmask (i.e., resulting in as few host addresses as possible) for a
network with 62 hosts in it?
I don't have any class like A,B,C
How can i find best fit netmask for ...
