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CIDR addressing question.
Posted: Wed Apr 30, 2014 11:24 am
by orangehand
I am struggling to understand what the following / after an IP address (not .0 or .255) is telling me.
This is from MS's website:
Outlook.com Outbound IP Space
Outlook.com sends e-mail from the following IP addresses:
* 65.54.190.0/26
* 65.54.190.64/26
* 65.54.190.128/26
* 65.54.190.192/26
Is the /26 of any relevance in this case? If it is, what is it telling me?
If anyone can clarify I would be v grateful.
Re: CIDR addressing question.
Posted: Wed Apr 30, 2014 11:35 am
by jarda
Search the forum for ip cheat sheet.
Re: CIDR addressing question.
Posted: Wed Apr 30, 2014 11:50 am
by orangehand
I couldnt find the cheat sheet, but if it's like all the other CIDR helpers out there it won't answer my question:
If you have an IP of 65.54.190.64/26, what is the relevance of /26 - why would I ever need to know more than just the IP?
Re: CIDR addressing question.
Posted: Wed Apr 30, 2014 1:03 pm
by jarda
It defines the subnet, address range, multicast address. It has nothing with mikrotik it is standard. Have you tried to google about at least?
Re: CIDR addressing question.
Posted: Wed Apr 30, 2014 5:36 pm
by jarda
You did not your homework well. Otherwise you would have find this:
http://forum.mikrotik.com/viewtopic.php ... 4&p=418752
Or use google, it is everywhere.
If you have 65.54.190.64/26, it means that it is the network address. You can use IPs from range 65.54.190.65-65.54.190.126, have netmask 255.255.255.192 and 65.54.190.127 is broadcast address.
Re: CIDR addressing question.
Posted: Wed Apr 30, 2014 6:20 pm
by datumtech
I am struggling to understand what the following / after an IP address (not .0 or .255) is telling me.
This is from MS's website:
Outlook.com Outbound IP Space
Outlook.com sends e-mail from the following IP addresses:
* 65.54.190.0/26
* 65.54.190.64/26
* 65.54.190.128/26
* 65.54.190.192/26
Is the /26 of any relevance in this case? If it is, what is it telling me?
If anyone can clarify I would be v grateful.
These are the subnets of your network
65.54.190.0(broadcast ID) 65.54.190.1 - 62( IP Range) 65.54.190.63(Network ID)
255.255.255.192 will your subnet mask
Meaning in this network your have only 62 IPs to use
65.54.190.64 and the rests are in different network
Re: CIDR addressing question.
Posted: Wed Apr 30, 2014 6:29 pm
by datumtech
I am struggling to understand what the following / after an IP address (not .0 or .255) is telling me.
This is from MS's website:
Outlook.com Outbound IP Space
Outlook.com sends e-mail from the following IP addresses:
* 65.54.190.0/26
* 65.54.190.64/26
* 65.54.190.128/26
* 65.54.190.192/26
Is the /26 of any relevance in this case? If it is, what is it telling me?
If anyone can clarify I would be v grateful.
65.54.190.0(broadcast ID) 65.54.190.1 - 62(IP Range) 65.54.190.63(Network ID)
meaning you have 62 available IPs in this network and the subnet mask is 255.255.255.192
65.54.190.64 and the rest are another network
Re: CIDR addressing question.
Posted: Wed Apr 30, 2014 9:11 pm
by CelticComms
To be clear here - it MS say that email may come from the 65.54.190.64/26 block then you should assume that it means from any of the IPs from .64 to .127 . The restriction on the use of .64 and .127 only occurs if the block is applied to a broadcast network such as Ethernet. In other situations all the addresses may be used.