Reply to post: Re: The internet will be privatised

We are absolutely, definitively, completely and utterly out of IPv4 addresses, warns RIPE

Jellied Eel Silver badge

Re: The internet will be privatised

A while back this one ISP was issuing /28's for a DSL service [that I was testing at the time], instead of using PPPoE or some other means of "just having one IP address", esentially using one as a gateway, one as the actual IP address, a third for broadcast, and a fourth that was basically 'wasted'. It was an ineffective use of 4 assigned IP addresses in my opinion, but unfortunately necessary in THAT configuration.

Some ISPs just want to see the blocks burn. Or went on an IP training course when instructors still waxed lyrical about Class A/B/C networks & not drugs. A /28 is 16 v4 addresses though, but there's still a suprising number of ISPs that think you must use /30 (4 IPs) on a point-to-point link.. Just in case a 2-endpoint scheme gets confused about subnet zero and broadcasts. Or perhaps they've got some legacy wiretapping kit that requires it's own address.

But re-doing addresses is far from trivial, especially given the lack of out-band connections meaning if there's an 'oops', you can lose access to the far-end device. Other tricks can work, ie using RFC1918 addressing for P2P links, especially consumer ones, but that has been frowned on by purists.

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