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Who holds an IP address, prefix or AS number, how it is routed (origin AS, RPKI, IRR), its reverse DNS, blocklist listings and PeeringDB record, with what to fix first.

IP address, prefix or AS number

AS21508 · 

curl -s "https://thenetworkery.com/api/v1/network-report?query=AS21508"
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Warning: AS21508 (COMCAST-21508) announces 17 IPv4 and 61 IPv6 prefixes. 4 warnings

AS pageAS21508
HolderCOMCAST-21508 - Comcast Cable Communications, LLC
AllocationARIN, United States (US), assigned 2001-05-16
Prefixes (IPv4 / IPv6)17 / 61
RPKI valid91% (71 / 78)
Upstreams and peers1
Peering policyRestrictive

What to fix

  1. Warning

    7 of 78 announced prefixes have no ROA (RPKI not found): 141.104.0.0/16, 157.240.147.0/24, 157.240.148.0/24, 173.242.174.0/24, 198.90.112.0/22 (+2).

    Without a ROA, networks cannot tell your routes from a hijack.

    Fix: Create a ROA for each at your RIR portal, with origin AS21508 and a max length equal to the prefix length:

    141.104.0.0/16 AS21508 max-length /16
157.240.147.0/24 AS21508 max-length /24
157.240.148.0/24 AS21508 max-length /24
173.242.174.0/24 AS21508 max-length /24
198.90.112.0/22 AS21508 max-length /22
204.194.47.0/24 AS21508 max-length /24
205.223.19.0/24 AS21508 max-length /24

    Open in RPKI / ROA validator Guide

  2. Warning

    76 of 78 announced prefixes have no IRR route object: 50.217.207.0/24, 2001:559:81d7::/48, 2001:559:c174::/48, 2001:559:875f::/48, 2001:559:c4f6::/48 (+71).

    Many networks build their prefix filters from IRR data; without route objects some of them drop the routes.

    Fix: Create route (IPv4) and route6 (IPv6) objects with origin AS21508 in your RIR’s IRR database (or RADB).

    route: 50.217.207.0/24
origin: AS21508

route6: 2001:559:81d7::/48
origin: AS21508

route6: 2001:559:c174::/48
origin: AS21508

    Open in ASN & BGP prefix lookup

  3. Warning

    No IRR as-set is listed.

    Peers and route servers build prefix filters from the as-set. Without one they fall back to the AS number alone, which breaks as soon as you have customers.

    Fix: Create an as-set in your RIR’s IRR database and add it to your PeeringDB record.

    Open in PeeringDB lookup

  4. Warning

    No public NOC, policy or technical contact.

    Other networks use these addresses to set up peering and to reach you during an incident.

    Fix: Add a role contact (for example noc@ or peering@ an address you monitor) with visibility Public.

    Open in PeeringDB lookup

Checks

Routing and RPKI 7 of 78 announced prefixes have no ROA (RPKI not found): 141.104.0.0/16, 157.240.147.0/24, 157.240.148.0/24, 173.242.174.0/24, 198.90.112.0/22 (+2).
  • Pass: AS21508 announces 17 IPv4 and 61 IPv6 prefixes.
  • Warning: 7 of 78 announced prefixes have no ROA (RPKI not found): 141.104.0.0/16, 157.240.147.0/24, 157.240.148.0/24, 173.242.174.0/24, 198.90.112.0/22 (+2).
  • Info: 71 of 78 announced prefixes are RPKI valid.
  • Warning: 76 of 78 announced prefixes have no IRR route object: 50.217.207.0/24, 2001:559:81d7::/48, 2001:559:c174::/48, 2001:559:875f::/48, 2001:559:c4f6::/48 (+71).
  • Info: One upstream or peer seen (AS7922): an outage there takes the whole network off the internet.
HolderCOMCAST-21508 - Comcast Cable Communications, LLC
IPv4 prefixes17
IPv6 prefixes61
RPKI71 valid · 7 not found
Without IRR route object76
Downstream networks50
Routes to fix
PrefixRPKI
141.104.0.0/16 No ROA
157.240.147.0/24 No ROA
157.240.148.0/24 No ROA
173.242.174.0/24 No ROA
198.90.112.0/22 No ROA
204.194.47.0/24 No ROA
205.223.19.0/24 No ROA

Upstreams and peers seen to the left 1

AS7922 Comcast

Announced prefixes 78

50.204.101.0/24 50.205.217.0/24 50.216.229.0/24 50.217.1.0/24 50.217.207.0/24 50.218.47.0/24 50.228.113.0/24 50.229.113.0/24 50.229.114.0/24 50.235.34.0/24 141.104.0.0/16 157.240.147.0/24 157.240.148.0/24 173.242.174.0/24 198.90.112.0/22 204.194.47.0/24 205.223.19.0/24 2001:559:3ac::/48 2001:559:3b9::/48 2001:559:3c8::/48 2001:559:5c9::/48 2001:559:5db::/48 2001:559:7a7::/48 2001:559:7db::/48 2001:559:8a::/48 2001:559:37d::/48 2001:559:40a::/48 2001:559:49a::/48 2001:559:49b::/48 2001:559:53c::/48 2001:559:72b::/48 2001:559:73c::/48 2001:559:78a::/48 2001:559:79d::/48 2001:559:79e::/48 2001:559:81bf::/48 2001:559:81d7::/48 2001:559:81d8::/48 2001:559:82fd::/48 2001:559:85c1::/48 2001:559:85ff::/48 2001:559:87b2::/48 2001:559:220::/48 2001:559:243::/48 2001:559:280::/48 2001:559:788::/48 2001:559:804c::/48 2001:559:833e::/48 2001:559:841c::/48 2001:559:871a::/48 2001:559:875f::/48 2001:559:8201::/48 2001:559:8416::/48 2001:559:8445::/48 2001:559:8535::/48 2001:559:8604::/48 2001:559:8773::/48 2001:559:c0::/48 2001:559:c0f6::/48 2001:559:c0f7::/48 2001:559:c071::/48 2001:559:c1a5::/48 2001:559:c1ca::/48 2001:559:c2a7::/48 2001:559:c3e9::/48 2001:559:c4db::/48 2001:559:c4f6::/48 2001:559:c10a::/48 2001:559:c28f::/48 2001:559:c45f::/48 2001:559:c174::/48 2001:559:c290::/48 2001:559:c344::/48 2001:559:c458::/48 2001:559:c460::/48 2001:559:c515::/48 2001:559:c538::/48 2001:559:f7::/48

Source: RIPEstat (RIPE NCC RIS, Routinator, IRR); AS names: Team Cymru

Open in ASN & BGP prefix lookup
Registration Found at rdap.arin.net.
  • Pass: Found at rdap.arin.net.
NameCOMCAST-21508
HandleAS21508
RangeAS21508
Statusactive
Registered2001-05-16T00:00:00-04:00
Last changed2021-01-25T15:20:02-05:00
Abuse contactabuse@comcast.net
Allocation
Registry (RIR)ARIN
CountryUnited States (US)
Delegated on2001-05-16
StatusAssigned
Delegated rangeAS21508

Source: RIR delegation data, updated daily. The country is where the range was registered, not necessarily where it is used.

Contacts
RoleNameEmail
registrant Comcast Cable Communications, LLC

Source: https://rdap.arin.net/registry/autnum/21508. Registration data from rdap.arin.net, shown under its terms of use (terms): not for marketing or bulk collection.

Open in WHOIS / RDAP lookup
PeeringDB No IRR as-set is listed.
  • Pass: AS21508 is in PeeringDB as Comcast - Richmond.
  • Info: Peering policy: Restrictive.
  • Info: No internet exchange ports are listed.
  • Warning: No IRR as-set is listed.
  • Warning: No public NOC, policy or technical contact.
  • Info: The record was last updated 2022-07-27.
NetworkComcast - Richmond (Comcast - Richmond)
AS numberAS21508
TypeCable/DSL/ISP, Regional
Prefixes (IPv4 / IPv6)0 / 0
TrafficNot Disclosed
Peering policyRestrictive
Policy URLhttp://www.comcast.com/peering
LocationsNot Required
Ratio requiredYes
ContractsRequired
Last updated2022-07-27

Source: PeeringDB. Results are cached for an hour.

Open in PeeringDB lookup