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"No Proxy for" example

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  • Last reply by cubewano

cubewano
cubewano
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There's an example in the manual proxy configurations under the "No Proxy for" field:

192.168.1.0/24

What does this mean exactly? Is 24 the upper bound of the IP range (i.e. 192.168.1.0 - 192.168.1.24)? Is it a mask? I seem to be able to connect to anything on 192.168.1.xxx with this setting.

There's an example in the manual proxy configurations under the "No Proxy for" field: 192.168.1.0/24 What does this mean exactly? Is 24 the upper bound of the IP range (i.e. 192.168.1.0 - 192.168.1.24)? Is it a mask? I seem to be able to connect to anything on 192.168.1.xxx with this setting.

All Replies (6)

cubewano
cubewano Question owner
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Ok, apparently it's CIDR notation, so the 24 indeed forms the netmask (255.255.255.0) for class C.

cor-el
cor-el
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It specifies the number of bits in the mask, so 24 means 24 bits. That is the whole 192.xxx.xxx.xxx range. If you only need 192.168.1.xxx then 192.168.1.0/8 is sufficient.

See also http://kb.mozillazine.org/network.proxy.no_proxies_on

cubewano
cubewano Question owner
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Not according to the CIDR calculator: http://www.subnet-calculator.com/cidr.php . It's the first 24 bits (left to right) which are set to 1 in the netmask. So if you want 192.168.1.xxx the CIDR notation is 192.168.1.0/24 (CIDR Netmask 255.255.255.0).

cubewano
cubewano Question owner
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I should add: 192.168.1.0/8 will leave you with the 192.xxx.xxx.xxx range (netmask 255.0.0.0), effectively the same as 192.0.0.0/8

cor-el
cor-el
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Thanks for the correction. See also http://en.wikipedia.org/wiki/CIDR_notation

cubewano
cubewano Question owner
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Sure thing. Also check out http://en.wikipedia.org/wiki/Classful_network for a historical perspective of network classes.