Given a IP range as zz.yy+4.xx.0
Can anyone help me how to find a subnet mask for this?
I feel CIDR notation is missing.
Appreciate your help
No, it is not possible to determine the subnet mask from an IP address alone.
Related
Be appreciative if anyone has the knowledge to give me a little help with this, as I have no idea why this is happening.
So I have the ship to alternative address option enabled, when I select the option, shipping methods are not available.
No issue at all when delivering to the same address as billing, only when I select the deliver to alternative address option.
Any help would be much appreciated, as i'm going round in circles with this one.
Many thanks in advance.
Arron
I am curently looking for a dictionary that contains all (or a lot) of interfaces names for routers and switches.
For instance a dictionary that would look like this :
[[Cisco : GigabithEthernet1/0/0, ..., GigabithEthernet1/0/28, FastEthernet1/0/0, ...],
[Juniper : ge-0/0/1, ..., ge-0/0/12,fa-0/0/1, ...,fa-0/0/12]]
I would like it to contain as much of interfaces names of as much of brand as possible.
I have already been looking for it for a long time now, but I have not been able to find anything so far. So if anyone has something to share on this it would be very much appreciated.
Thanks for reading.
A quick update to inform you that I have not been able to find a dictionnary and that after some research I find out that you don't need one if your problem is to identify interfaces on a switch or router.
Using SNMP, you can find which one of the interfaces on your machine is a physical or logical interface. So I used this reference to know which one of my interfaces are physical interfaces or not.
The OID is : 1.3.6.1.2.1.2.2.1.3
Thanks for the help I have been given so far !
I've seen around IPv4 subnet address ranges expressed in a compact form.
For example:
127/24 == 127.0.0.0/24
10/8 == 10.0.0.0/8
10.10.10/24 == 10.10.10.0/24
BTW I can't find any RFC (or any other kind of official or semi-official documentation) that describes it.
Does anyone have some links to share?
I recall this notation being used on Juniper routers as far back as 2001; not sure what, if any, RFC defined it. RFCs do not define the whole planet; somehow over the years they replaced specifications (which are/were much more detailed), but were originally intended for Request For Comments. (Gee, I wonder why there are so many bugs in networking gear.)
In RFC 5952 - section 5 it is stated that for some IPv6 addresses it is recommended to give the mixed notation, if it has a certain prefix. However, it is unclear which prefixes are used for this, because it is stated that a prefix may be used if it is commonly used as a prefix for a IPv4-mapped address. Thus meaning basically any prefix could be used for this.
Now my question is:
May every IPv6 address be written as an IPv4-mapped IPv6-address?
If not, what are the exact rules for correctly writing an IPv4-mapped IPv6-address?
You may use the IPv4 notation for the last 32 bits in any IPv6 address. The RFC you mention is about the recommended notation. It doesn't specify all correct notations. The RFC that defines that is https://www.rfc-editor.org/rfc/rfc4291#section-2.2 and it allows the IPv4 style notation (Note that it isn't called "IPv4-mapped IPv6-address", that is actually a special range of addresses that commonly used this notation style) for any address.
In this question I can easily see why a and c are using eBGP. However, why is b and d iBGP instead of OSPF and RIP respectively?
Thanks
Edit: This is an excerpt from Computer Networking by Kurose and Ross.
This should answer all your questions.
This is a horrendous example, because it doesn't detail which nodes are actually speaking iBGP ( nor the 'why' ), but the reason b and d get the information from iBGP is because the prefix has no method to make it into the IGP. This could change easily though if you configured the EBGP speaking nodes to redistribute the eBGP learned routes into their respective IGPs ( OSPF and RIP respectively )