Potholes to avoid when migrating to IPv6

Re:Potholes to avoid when migrating to IPv6 by mgerdts on Monday December 31, 2018 @09:07AM (#18794514)

Not just ipv6.

  $ ping 127.1
  PING 127.1 (127.0.0.1): 56 data bytes
  ...
  $ ping $(((127 << 24) + 1))
  PING 2130706433 (127.0.0.1): 56 data bytes
  ...

I've primarily seen the second form in the early days of the web when spammers were presumably trying to bypass mail or web filters that were scanning for blacklisted IPs.

Edit: fix formatting

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Re:Potholes to avoid when migrating to IPv6 by mschuster91 on Monday December 31, 2018 @09:20AM (#18794573)

Hex works too (tested on OS X):

    ping 0x7f000001
    PING 0x7f000001 (127.0.0.1): 56 data bytes

or, as a URL (tested in OS X Chrome, and the URL formatter of HN also shows it, with Chrome hover showing 127.0.0.1): https://0x7f000001/

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