Report for 19721

Name

MHN - Magellan Health Services, US

AS Adjacency Report

In the context of this report "Upstream" indicates that there is an adjacent AS that lines between the BGP table collection point (in this case at AS2.0) and the specified AS. Similarly, "Downstream" refers to an adjacent AS that lies beyond the specified AS. This upstream / downstream categorisation is strictly a description relative topology, and should not be confused with provider / customer / peer inter-AS relationships.

19721 MHN - Magellan Health Services, US

  Adjacency:     2  Upstream:     2  Downstream:     0
  Upstream Adjacent AS list
    AS49915         MEGAPORT - Megaport (UK) Limited, GB
    AS3356          LEVEL3 - Level 3 Parent, LLC, US

Announced Prefixes

Rank  AS       Type    Originate Addr Space  (pfx)   Transit Addr space  (pfx)  Description
6825  AS19721        ORIGIN  Originate:      20224 /17.70  Transit:          0 /0.00  MHN - Magellan Health Services, US

Aggregation Suggestions

        Filter: Aggregates, Specifics

This report does not take into account conditions local to each origin AS in terms of policy or traffic engineering requirements, so this is an approximate guideline as to aggregation possibilities.

 Rank AS            AS Name                                      Current  Wthdw  Aggte  Annce Redctn       %
 7251 AS19721       MHN - Magellan Health Services, US                14      8      2      8      6  42.86%


  Prefix               AS Path                              Aggregation Suggestion
  204.193.64.0/19      4777 2516 3356 19721   
  204.193.64.0/20      4777 2497 3356 19721   
  204.193.71.0/24      4777 2516 3257 49915 19721   
  204.193.72.0/24      4777 2516 3257 49915 19721   
  204.193.74.0/23      4777 2516 3257 49915 19721 + Announce - aggregate of 204.193.74.0/24 (4777 2516 3257 49915 19721) and 204.193.75.0/24 (4777 2516 3257 49915 19721)
  204.193.74.0/24      4777 2516 3257 49915 19721 - Withdrawn - aggregated with 204.193.75.0/24 (4777 2516 3257 49915 19721)
  204.193.75.0/24      4777 2516 3257 49915 19721 - Withdrawn - aggregated with 204.193.74.0/24 (4777 2516 3257 49915 19721)
  204.193.80.0/20      4777 2516 3257 49915 19721   
  204.193.80.0/24      4777 2516 3257 49915 19721 - Withdrawn - matching aggregate 204.193.80.0/20 4777 2516 3257 49915 19721
  204.193.84.0/22      4777 2516 3356 19721   
  204.193.84.0/22      4777 2516 3257 49915 19721 + Announce - aggregate of 204.193.84.0/23 (4777 2516 3257 49915 19721) and 204.193.86.0/23 (4777 2516 3257 49915 19721)
  204.193.84.0/24      4777 2516 3257 49915 19721 - Withdrawn - aggregated with 204.193.85.0/24 (4777 2516 3257 49915 19721)
  204.193.85.0/24      4777 2516 3257 49915 19721 - Withdrawn - aggregated with 204.193.84.0/24 (4777 2516 3257 49915 19721)
  204.193.86.0/23      4777 2516 3257 49915 19721 - Withdrawn - aggregated with 204.193.84.0/23 (4777 2516 3257 49915 19721)
  204.193.88.0/24      4777 2516 3257 49915 19721 - Withdrawn - matching aggregate 204.193.80.0/20 4777 2516 3257 49915 19721
  204.193.93.0/24      4777 2516 3257 49915 19721 - Withdrawn - matching aggregate 204.193.80.0/20 4777 2516 3257 49915 19721

Advertisements that are fragments of the original RIR allocation (more specifics) originated by this AS.

AS19721   13 More Specifics   14 Total Advertisements   MHN - Magellan Health Services, US
    204.193.64.0/20               204.193.64.0/19
    204.193.71.0/24               204.193.64.0/19
    204.193.72.0/24               204.193.64.0/19
    204.193.74.0/24               204.193.64.0/19
    204.193.75.0/24               204.193.64.0/19
    204.193.80.0/20               204.193.64.0/19
    204.193.80.0/24               204.193.64.0/19
    204.193.84.0/22               204.193.64.0/19
    204.193.84.0/24               204.193.64.0/19
    204.193.85.0/24               204.193.64.0/19
    204.193.86.0/23               204.193.64.0/19
    204.193.88.0/24               204.193.64.0/19
    204.193.93.0/24               204.193.64.0/19

Whois Entry

whois: 402603

IANA has recorded AS19721 as originally allocated by 
/usr/bin/whois -h jwhois.apnic.netr "AS19721\n             
             #
             # ARIN WHOIS data and services are subject to the Terms of Use
             # available at: https://www.arin.net/resources/registry/whois/tou/
             #
             # If you see inaccuracies in the results, please report at
             # https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
             #
             # Copyright 1997-2026, American Registry for Internet Numbers, Ltd.
             #
             
             
             ASNumber:       19721
             ASName:         MHN
             ASHandle:       AS19721
             RegDate:        2001-02-07
             Updated:        2012-03-20
             Ref:            https://rdap.arin.net/registry/autnum/19721
             
             
             OrgName:        Magellan Health Services
             OrgId:          MHS-54
             Address:        13736 Riverport Dr.
             City:           Maryland Heights
             StateProv:      MO
             PostalCode:     63043
             Country:        US
             RegDate:        2001-02-07
             Updated:        2026-06-05
             Ref:            https://rdap.arin.net/registry/entity/MHS-54
             
             
             OrgNOCHandle: STLNE-ARIN
             OrgNOCName:   stlnetengineering
             OrgNOCPhone:  +1-314-387-4000 
             OrgNOCEmail:  NetworkInfrastructure@magellanhealth.com
             OrgNOCRef:    https://rdap.arin.net/registry/entity/STLNE-ARIN
             
             OrgTechHandle: STLNE-ARIN
             OrgTechName:   stlnetengineering
             OrgTechPhone:  +1-314-387-4000 
             OrgTechEmail:  NetworkInfrastructure@magellanhealth.com
             OrgTechRef:    https://rdap.arin.net/registry/entity/STLNE-ARIN
             
             OrgAbuseHandle: HEAPB-ARIN
             OrgAbuseName:   Heap, Brandon 
             OrgAbusePhone:  +1-801-367-9127 
             OrgAbuseEmail:  heapb@magellanhealth.com
             OrgAbuseRef:    https://rdap.arin.net/registry/entity/HEAPB-ARIN
             
             OrgNOCHandle: WEBBA33-ARIN
             OrgNOCName:   Webb, Arron 
             OrgNOCPhone:  +1-832-622-0113 
             OrgNOCEmail:  webba3@magellanhealth.com
             OrgNOCRef:    https://rdap.arin.net/registry/entity/WEBBA33-ARIN
             
             OrgTechHandle: WEBBA33-ARIN
             OrgTechName:   Webb, Arron 
             OrgTechPhone:  +1-832-622-0113 
             OrgTechEmail:  webba3@magellanhealth.com
             OrgTechRef:    https://rdap.arin.net/registry/entity/WEBBA33-ARIN
             
             OrgAbuseHandle: STLNE-ARIN
             OrgAbuseName:   stlnetengineering
             OrgAbusePhone:  +1-314-387-4000 
             OrgAbuseEmail:  NetworkInfrastructure@magellanhealth.com
             OrgAbuseRef:    https://rdap.arin.net/registry/entity/STLNE-ARIN
             
             OrgNOCHandle: HEAPB-ARIN
             OrgNOCName:   Heap, Brandon 
             OrgNOCPhone:  +1-801-367-9127 
             OrgNOCEmail:  heapb@magellanhealth.com
             OrgNOCRef:    https://rdap.arin.net/registry/entity/HEAPB-ARIN
             
             OrgTechHandle: HEAPB-ARIN
             OrgTechName:   Heap, Brandon 
             OrgTechPhone:  +1-801-367-9127 
             OrgTechEmail:  heapb@magellanhealth.com
             OrgTechRef:    https://rdap.arin.net/registry/entity/HEAPB-ARIN
             
             OrgDNSHandle: WEBBA33-ARIN
             OrgDNSName:   Webb, Arron 
             OrgDNSPhone:  +1-832-622-0113 
             OrgDNSEmail:  webba3@magellanhealth.com
             OrgDNSRef:    https://rdap.arin.net/registry/entity/WEBBA33-ARIN
             
             OrgRoutingHandle: WEBBA33-ARIN
             OrgRoutingName:   Webb, Arron 
             OrgRoutingPhone:  +1-832-622-0113 
             OrgRoutingEmail:  webba3@magellanhealth.com
             OrgRoutingRef:    https://rdap.arin.net/registry/entity/WEBBA33-ARIN
             
             OrgDNSHandle: HEAPB-ARIN
             OrgDNSName:   Heap, Brandon 
             OrgDNSPhone:  +1-801-367-9127 
             OrgDNSEmail:  heapb@magellanhealth.com
             OrgDNSRef:    https://rdap.arin.net/registry/entity/HEAPB-ARIN
             
             OrgRoutingHandle: HEAPB-ARIN
             OrgRoutingName:   Heap, Brandon 
             OrgRoutingPhone:  +1-801-367-9127 
             OrgRoutingEmail:  heapb@magellanhealth.com
             OrgRoutingRef:    https://rdap.arin.net/registry/entity/HEAPB-ARIN
             
             OrgAbuseHandle: WEBBA33-ARIN
             OrgAbuseName:   Webb, Arron 
             OrgAbusePhone:  +1-832-622-0113 
             OrgAbuseEmail:  webba3@magellanhealth.com
             OrgAbuseRef:    https://rdap.arin.net/registry/entity/WEBBA33-ARIN
             
             RTechHandle: DB1528-ARIN
             RTechName:   Brack, David 
             RTechPhone:  +1-314-387-4055 
             RTechEmail:  dabrack@magellanhealth.com
             RTechRef:    https://rdap.arin.net/registry/entity/DB1528-ARIN
             
             
             #
             # ARIN WHOIS data and services are subject to the Terms of Use
             # available at: https://www.arin.net/resources/registry/whois/tou/
             #
             # If you see inaccuracies in the results, please report at
             # https://www.arin.net/resources/registry/whois/inaccuracy_reporting/
             #
             # Copyright 1997-2026, American Registry for Internet Numbers, Ltd.
             #