im kinda stuck. I have IP 192.168.10.100, 255.255.255.0 and I need to find out how many bits belongs to the host portion of the address. I know that last part of address is host part which will be 8 bits but I got feeling that it's wrong ... can someone explain where i do mistake.
Thanks
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I think my issue comes from a lack of understanding exactly how the IPv6 multicast actually works but I had a hard time following the articles I found online.
The issue I'm trying to solve is how to configure a machine's network to join the specific IPv6 multicast address "ff02::1:e000:0700"
My IPv6 link address is "fe80::204:5fff:fea7:c84b" for reference.
So using another machine on the net, I can ping ff02::1 for instance and see my ip in the list of DUP responses as expected. I'm trying to understand what aspect I would need to configure to allow it to respond if I pinged the ff02::1:e000:0700 address.
I'm a novice with networking and am learning as I go. I appreciate any help or insight. Thanks!
I am now maintaining a piece of code that has a warning not to use the value 0 or 255 in an IP address for hosts.
Can someone help and shed some light on the restriction, if any, on IP address for host? It is mandatory to backup the info from a trusted source.
I found a few sources around the internet but non are official or trusted enough.
The most reliable info I found until now is located at RFC1123 section 2.5 and here at the IANA IPv4 Address Space Registry.
Back in the days of Class A, B, and C addresses, a class C address that ended in .0 referred to the entire subnet, and .255 was the broadcast address for the subnet. So these addresses couldn't be used for individual hosts.
However, address classes became obsolete decades ago, when Classless Inter-Domain Routing (CIDR) was developed to make more efficient use of IP addresses. This is described in RFC 4632. The general idea is that each network has an explicit subnet mask, which need not exactly match octet boundaries in IP addresses. So the assumption that .0 and .255 are the network and broadcast addresses is no longer valid.
I don't know which software / library you're using, but I vaguely remember reading this a few years ago about IP address schemes of days long past. In any way, today there's no such rule.
Its a small and simple question, But still i didn't get in an online.
I just trying to find out my IP address of my computer.
So with help of online, I just follow www.whatismyip.com . so it shows like this "xxx.xxx.xxx.xxx".
And when i run IPCONFIG in my command prompt, it shows ip address and default gateway.
But it is totally different these ip address[which is got from online and from cmd prompt].
So i just confused,
what is the ip address from "this website <www.whatismyip.com> and
what is the ip address from cmd prompt.
When i refer in online, there are 2 types of ip address[public and private].
I just confused with these ip addresses. Can anyone please help me to explain me about this?
Thanks in advance.
Public IP address is that one which allows that people can access to your web site/app from anywhere on Internet. Private IP is that one which belongs to your Internet local network (your home or another LAN).
I have connected my network connection through the wireless device with DHCP. Recently I have changed my connection from wireless to wired cable connection.
At that time My IP address got changed automatically,
I tried these steps Changing Your Private IP to have my past IP address but also it changes automatically.
Now, when I check my IP address it shows a different IP from before. That makes 3 changes, my confusion is around whether it changes itself once per day or not. If anyone has an answer for this, please let me know.
Are you sure you talk about private IP and not Public one ?
Did you try going back to wireless for few days and watch if your private IP don't change ?
Some details are missing so I can't probably make a good diagnosis of what you have here. But for now I'll try to help out.
If you are talking about your public IP address it's normal that it'll get changed quite often, unless you have signed up on your ISP for a static public IP address (ex. you told you're ISP that you'll be running a web server). It's normal for the IP to change in intervals, days, hours or even minutes if your ISP has lots of users.
If you're talking about your local IP address, you should check your router out (assuming you use one), check if how many people are using/connected to it.
OK, so we're dealing with Private IP. Your problem is it changing whenever you Disconnect/Connect right? Are you the only user? Or are you suspecting the router might be spewing out random IPs from the IP pool even if the previous ones aren't already allocated?
Ex.
a) You connect, router gives you 192.168.0.2
b) You disconnect
c) Some other PC connects and gives 192.168.0.2
d) You connect again and router gives you 192.168.0.3
Are you talking something like the above situation?
EDIT: Silly me, found out that I can comment on my own answer.
I'm looking for some Linux code to find an IP address from an Ethernet address. I suppose I have to do some inverse ARP trickery but I don't find any example...
http://compnetworking.about.com/od/networkprotocolsip/f/convertipmacadd.htm
Try sending an IP broadcast (e.g. ping 192.168.1.255 if your subnet is 192.168.1.0/24) to prime your ARP cache, followed by arp -a to spit it all out.
For computers that you have communicated with, you can look at their arp entry. This is available in text format in /proc/net/arp for example. Finding an IP address for a MAC that you know but haven't communicated with is significantly more difficult. The closest match, protocol-wise, would be RARP but that's hardly ever in use so your are not likely to get a response.
You can always scan your local subnet to make sure you get a full view in your arp table. See for example fping for an efficient way to do this. Note that hosts don't actually need to respond to the pings in question to appear in the ARP table, so this is useful even in the presence of local firewalls etc.
Take a look at Thomas Habet's Arping. I've not tried it, but the basic idea is to send an ICMP Ping network packet to the MAC address in question using a broadcast destination IP address in the IP header. Only the host with the specified MAC address will reply and the reply will (usually) contain its IP address. It won't always work but it might be good enough for you. See the project readme for limitations.