A listing in one of Azure networks reveals following address space ace::/64
What it is?
It's the short form for an IPv6 address. The extended form would be ace:0:0:0:0:0:0:0, however, blocks with 0 can be shortened with the double colon, so the result is ace::. The /64 means, that the address block marked by this address contains 2^64 addresses (an IPv6 address has 128 bits, and in this case 64 bits describe the network, and the other 64 can be assigned to actual devices in the network).
Related
I read in a article about that 64k io port each are address assigned to 8bit register and when you combine io port together you get 16 bit,32bit etc. Sorry i am not getting that website in my history now so i cant provide link.
I just not understood what it want to say so i just put the raw form here
So there are mine few points that i want confirmation on as i am confused bcoz as i accidently land on another website they have just another idea.
i) i/o ports are assigned to registers of peripherals. These are of 16bit as there are 64k port and register they are assigned to can be of any size(8,16,32,64bit).
ii)Except for pci related devices io port address number are fixed,but as in device with configuration space register can be assigned io address number using bar any number one want just i should not be used by anyother device.
Que1)When a address come out of processor it goes to motherboard through northbridge/system_agent and it routes it according to address map it has, peripheral device are told to accept i/o range or memory address range on basis of what was configured in bar,but as northbridge is made up of many controller [like memory,graphics,pci etc] but it is who, who has address mapping to route.
queii) according to intel 82815 gmch northbridge page 129 section 4.3
"The processor allows 64K+3 bytes to be addressed within the I/O
space. The GMCH propagates the processor I/O address without any
translation on to the destination bus"
What does this means it only routes mmio and io bar but than how rest of io address(that are not assigned by software or due to i/o bar register) are decided. where should they go how peripheral device know this address it should acccept,if they are just thrown on the bus than how CS pin is decided of particular device
I'm trying to pentest some IPSEC implementation for a uni project, and following this guide I'm stuck at:
Step 1 (common): Forging an ICMP PTB packet from the untrusted network The attacker first has to forge an appropriate ICMP PTB packet (a single packet is sufficient). This is done by eavesdropping a valid packet from the IPsec tunnel on the untrusted network. Then the attacker forges an ICMP PTB packet, specifying a very small MTU value equal or smaller than 576 with IPv4 (resp. 1280 with IPv6). The attacker can use 0 for instance. This packet spoofs the IP address of a router of the untrusted network (in case the source IP address is checked), and in order to bypass the IPsec protection mechanism against blind attacks, it includes as a payload a part of the outer IP packet that has just been eavesdropped. This is the only packet an attacker needs to send. None of the following steps involve the attacker.
I know what MTU is, but what does the bold statement mean?
How do I set the MTU size of a packet with scapy?
It means that I have to set the size of a IP packet less than 576 bytes?
It's already set to 140 B,at least it shows this with len command.
There's something that I didn't get right, maybe I have to set the fragmentation?
I know nothing about the subject, but some quick searching seems to indicate that it's referring to an IPv6 ICMP packet with a type of 2 ("packet too big").
Then from some poking around scapy, this appears to be how you'd create one:
from scapy.layers.inet6 import ICMPv6PacketTooBig
icmp_ptb = ICMPv6PacketTooBig(mtu=0)
Of course though, you'll need to do some testing to verify this.
Screenshot of error
I am trying to make Virtual network on azure cloud,
I tried giving Address space 255.255.255.0/24 , which i think means is that first 24 bits are reserved.
I want to know what can be the address range which can be given to my virtual network?
Anybody who can explain it in more detail or provide link, will be helpful.
Thanks in advance.
This solved my problem:
Address space: 192.168.0.0/24 (192.168.0.0 - 192.168.0.255)
Address Range: 192.168.0.0/24
This puts address range within address space.
Though more explanation is welcome.
What I understand so far is address width is the number of bits in an address.
For example, 4 bits width address can have 2^4 = 16 cases. And what I'm really uncertain is addressability. Based on what I learned is "the size of the most basic unit that can be named by address". So, if we have 4 bits address width and 2 bits addressability, what happens?
I've been really curious about it for a couple of weeks, but still bummer.
Could you guys explain those things by drawing or something?
I think you do get it. There is the number of address bits, the width if you will, and there is the size of the unit those things address. so 8 bits means you have 256 things, 16 bits of address 65536 things. The size of thing is completely independent of the number of address bits. From a programmers perspective almost always we deal in units of bytes, so 8 bits of address would be 256 bytes, 32 bits of address would be 4 gigabytes. As you dig into the logic it is often wasteful to use a byte based address, if you have a peripheral that has 32 bit wide registers and you can only access those as whole 32 bit registers then do you need to connect address line 0 or 1? often not. so at that peripheral the address bus however wide it is (often the whole address bus to the peripheral is a subset of the address bus higher up closer to the processor/software, and those address bits are in units of 32 bit words.
To make things even more confusing, memory parts are often defined in terms of bits, even if they have an 8 or 16 bit data bus. So you might have a 4M part but that is megabits not megabytes...
Can someone tell me the difference between Mac Address and Bluetooth Address in a BLE device?
Do they both have to be unique?
I've read that changing the bluetooth address affects the mac address?
Is it possible to have a different bluetooth address, but the same mac address?
What you are referring to Bluetooth Address is what more popularly known as static address which is a randomly generated address while the MAC address is unique and public.
The MAC address is created as per the IEEE 802-2001 standards in accordance with section 9.2: "48-bit universal LAN MAC addresses". They have a valid Organizationally Unique Identifier (OUI) obtained from the IEEE Registration Authority.
The MAC address is divided into the following two fields:
company_assigned field is contained in the 24 LSb.
company_id field is contained in the 24 MSb.
Whereas, A static address is a 48-bit randomly generated address created considering these requirements:
The two most significant bits of the static address shall be equal to ‘1’
Not all bits of the random part of the static address shall be equal to ‘1’
Not all bits of the random part of the static address shall be equal to ‘0’