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mappingipprefix

why those two IP prefixes, which are the same to me, map to the different AS number

I use the whois command to try to map two ip prefixes address to the AS numbers. The results are given blow:

$ whois -h whois.cymru.com " -v 1.0.4.0/22 "

AS | IP | BGP Prefix | CC | Registry | Allocated | AS Name

56203 | 1.0.4.0 | 1.0.4.0/24 | AU | apnic | 2011-04-12 | BIGRED-NET-AU Big Red Group

$ whois -h whois.cymru.com " -v 1.0.0.0/24 "

AS | IP | BGP Prefix | CC | Registry | Allocated | AS Name

15169 | 1.0.0.0 | 1.0.0.0/24 | AU | apnic | 2011-08-11 | GOOGLE - Google Inc.

My question is why those two prefixes have different AS number. It seems to me that those two are same, so the AS number should be also exact same number.

Many thanks for your help!

narisu

Solution

  • The two listings are on different subnets. This is caused by different subnet masks (the trailing /22 or /24 above).