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Community Member

the mask is 255.255.255.255???

my isp is Bell Sympatico, I use the SpeedStream5200 DSL modem, the IP/mask I got them are 67.71.88.19/32

who would like explain for me the mask is 255.255.255.255?

4 REPLIES
VIP Purple

Re: the mask is 255.255.255.255???

Hello,

most Internet Service Providers assign these 32-bit addresses called host addresses to individual users. The reason is that this is the best way to maximize their address space, since the 32-bit mask is the smallest 'subnet' you can have.

Hope that helps.

Regards,

GP

Community Member

Re: the mask is 255.255.255.255???

but i still confused about the 32-bit mask, it is legal or not?

thanks

VIP Purple

Re: the mask is 255.255.255.255???

Hello,

the 32-bit mask is perfectly legal, it is pretty much the same as when you define a host address (x.x.x.x/32) in an access list, it just applies to one single IP address. Another example would be loopback addresses, which are often configured with 32-bit masks.

Regards,

GP

Community Member

Re: the mask is 255.255.255.255???

The benefit of this configuration is not just preservation of address space, but enabling remote default gateway (out of subnet). Accounting of traffic within the network is eased when ISP is able to redirect traffic to AAA site. This conf is seen in dial-up enviroments also.

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