Routing security

AS21508 COMCAST-21508

Unclassified DROP-listed space ARIN

RPKI valid 91% 71 of 78 announcements

RPKI invalid 0 none

No ROA 7 not covered by any ROA

IRR registered 3% 71 missing · 5 other origin

ROAs 280 authorising this AS

Announcements

What this network originates

78 observed

Every prefix observed with AS21508 as its origin, checked against RPKI and the IRR. Problems sort first.

Prefix	RPKI	IRR	Vantage points
141.104.0.0/16	No ROA	IRR other origin	52
173.242.174.0/24	No ROA	No IRR	52
198.90.112.0/22	No ROA	IRR other origin	52
204.194.47.0/24	No ROA	IRR other origin	51
205.223.19.0/24	No ROA	IRR other origin	52
157.240.147.0/24	No ROA	IRR	51
157.240.148.0/24	No ROA	IRR	52
50.204.101.0/24	RPKI valid	No IRR	51
50.205.217.0/24	RPKI valid	No IRR	51
50.216.229.0/24	RPKI valid	No IRR	52
50.217.1.0/24	RPKI valid	No IRR	52
50.217.207.0/24	RPKI valid	No IRR	51
50.218.47.0/24	RPKI valid	No IRR	52
50.228.113.0/24	RPKI valid	No IRR	52
50.229.113.0/24	RPKI valid	No IRR	51
50.229.114.0/24	RPKI valid	No IRR	51
50.235.34.0/24	RPKI valid	No IRR	52
2001:559:3ac::/48	RPKI valid	No IRR	29
2001:559:3b9::/48	RPKI valid	No IRR	29
2001:559:3c8::/48	RPKI valid	No IRR	29
2001:559:5c9::/48	RPKI valid	No IRR	29
2001:559:5db::/48	RPKI valid	No IRR	29
2001:559:7a7::/48	RPKI valid	No IRR	29
2001:559:7db::/48	RPKI valid	No IRR	29
2001:559:8a::/48	RPKI valid	No IRR	29
2001:559:37d::/48	RPKI valid	No IRR	29
2001:559:40a::/48	RPKI valid	No IRR	29
2001:559:49a::/48	RPKI valid	No IRR	29
2001:559:49b::/48	RPKI valid	No IRR	29
2001:559:53c::/48	RPKI valid	No IRR	29
2001:559:72b::/48	RPKI valid	No IRR	29
2001:559:73c::/48	RPKI valid	No IRR	29
2001:559:78a::/48	RPKI valid	No IRR	29
2001:559:79d::/48	RPKI valid	No IRR	29
2001:559:79e::/48	RPKI valid	No IRR	29
2001:559:81bf::/48	RPKI valid	No IRR	29
2001:559:81d7::/48	RPKI valid	No IRR	29
2001:559:81d8::/48	RPKI valid	No IRR	29
2001:559:82fd::/48	RPKI valid	IRR other origin	29
2001:559:85c1::/48	RPKI valid	No IRR	29
2001:559:85ff::/48	RPKI valid	No IRR	29
2001:559:87b2::/48	RPKI valid	No IRR	29
2001:559:220::/48	RPKI valid	No IRR	29
2001:559:243::/48	RPKI valid	No IRR	29
2001:559:280::/48	RPKI valid	No IRR	29
2001:559:788::/48	RPKI valid	No IRR	29
2001:559:804c::/48	RPKI valid	No IRR	29
2001:559:833e::/48	RPKI valid	No IRR	29
2001:559:841c::/48	RPKI valid	No IRR	29
2001:559:871a::/48	RPKI valid	No IRR	29
2001:559:875f::/48	RPKI valid	No IRR	29
2001:559:8201::/48	RPKI valid	No IRR	29
2001:559:8416::/48	RPKI valid	No IRR	29
2001:559:8445::/48	RPKI valid	No IRR	29
2001:559:8535::/48	RPKI valid	No IRR	29
2001:559:8604::/48	RPKI valid	No IRR	29
2001:559:8773::/48	RPKI valid	No IRR	29
2001:559:c0::/48	RPKI valid	No IRR	29
2001:559:c0f6::/48	RPKI valid	No IRR	29
2001:559:c0f7::/48	RPKI valid	No IRR	29
2001:559:c1a5::/48	RPKI valid	No IRR	29
2001:559:c1ca::/48	RPKI valid	No IRR	29
2001:559:c2a7::/48	RPKI valid	No IRR	29
2001:559:c3e9::/48	RPKI valid	No IRR	29
2001:559:c4db::/48	RPKI valid	No IRR	29
2001:559:c4f6::/48	RPKI valid	No IRR	29
2001:559:c10a::/48	RPKI valid	No IRR	29
2001:559:c28f::/48	RPKI valid	No IRR	29
2001:559:c45f::/48	RPKI valid	No IRR	29
2001:559:c071::/48	RPKI valid	No IRR	29
2001:559:c174::/48	RPKI valid	No IRR	29
2001:559:c290::/48	RPKI valid	No IRR	29
2001:559:c344::/48	RPKI valid	No IRR	29
2001:559:c458::/48	RPKI valid	No IRR	29
2001:559:c460::/48	RPKI valid	No IRR	29
2001:559:c515::/48	RPKI valid	No IRR	29
2001:559:c538::/48	RPKI valid	No IRR	29
2001:559:f7::/48	RPKI valid	No IRR	29

RPKI · ROAs

Route origin authorisations

280 ROAs

Signed statements by address holders that AS21508 may originate these prefixes, up to the maximum length shown.

Prefix	Max length	Trust anchor
23.25.96.0/19	/19	ARIN
23.25.186.0/23	/23	ARIN
23.31.96.0/20	/20	ARIN
24.124.151.0/24	/24	ARIN
24.124.162.0/23	/23	ARIN
24.124.248.0/21	/21	ARIN
24.131.0.0/20	/20	ARIN
50.73.8.0/22	/22	ARIN
50.73.224.0/20	/20	ARIN
50.77.72.0/21	/21	ARIN
50.78.232.0/21	/21	ARIN
50.147.0.0/18	/18	ARIN
50.184.128.0/19	/19	ARIN
50.186.32.0/19	/19	ARIN
50.189.192.0/18	/18	ARIN
50.193.246.0/23	/23	ARIN
50.199.16.0/20	/20	ARIN
50.204.101.0/24	/24	ARIN
50.205.217.0/24	/24	ARIN
50.210.0.0/20	/20	ARIN
50.211.32.0/19	/19	ARIN
50.215.32.0/19	/19	ARIN
50.216.229.0/24	/24	ARIN
50.217.1.0/24	/24	ARIN
50.217.207.0/24	/24	ARIN
50.218.47.0/24	/24	ARIN
50.219.12.0/22	/22	ARIN
50.219.193.0/24	/24	ARIN
50.219.222.0/24	/24	ARIN
50.219.229.0/24	/24	ARIN
50.219.238.0/24	/24	ARIN
50.219.240.0/24	/24	ARIN
50.220.111.0/24	/24	ARIN
50.227.24.0/24	/24	ARIN
50.228.113.0/24	/24	ARIN
50.229.113.0/24	/24	ARIN
50.229.114.0/24	/24	ARIN
50.229.232.0/24	/24	ARIN
50.229.233.0/24	/24	ARIN
50.232.58.0/23	/23	ARIN
50.234.62.0/23	/23	ARIN
50.235.34.0/24	/24	ARIN
50.237.96.0/24	/24	ARIN
50.240.80.0/20	/20	ARIN
50.242.32.0/19	/19	ARIN
50.245.224.0/19	/19	ARIN
50.251.112.0/20	/20	ARIN
50.253.208.0/20	/20	ARIN
64.139.66.0/24	/24	ARIN
64.139.70.0/24	/24	ARIN
64.139.79.0/24	/24	ARIN
64.139.90.0/24	/24	ARIN
66.208.224.0/23	/23	ARIN
66.208.230.0/24	/24	ARIN
66.208.234.0/24	/24	ARIN
67.163.96.0/19	/19	ARIN
67.166.160.0/19	/19	ARIN
67.172.192.0/19	/19	ARIN
67.174.64.0/20	/20	ARIN
67.187.0.0/19	/19	ARIN
68.85.70.0/23	/23	ARIN
68.85.214.0/24	/24	ARIN
68.85.226.0/24	/24	ARIN
68.86.14.0/24	/24	ARIN
68.86.24.0/24	/24	ARIN
68.86.124.0/22	/22	ARIN
68.86.172.0/22	/22	ARIN
68.86.200.0/24	/24	ARIN
68.87.3.0/24	/24	ARIN
69.139.165.0/24	/24	ARIN
69.139.186.0/24	/24	ARIN
69.139.206.0/24	/24	ARIN
69.139.223.0/24	/24	ARIN
69.241.48.0/23	/23	ARIN
69.241.85.0/24	/24	ARIN
69.243.208.0/20	/20	ARIN
69.244.224.0/20	/20	ARIN
69.252.18.0/23	/23	ARIN
70.88.24.0/23	/23	ARIN
70.88.164.0/24	/24	ARIN
70.88.168.0/23	/23	ARIN
70.88.184.0/21	/21	ARIN
70.89.232.0/21	/21	ARIN
70.91.162.0/24	/24	ARIN
71.24.32.0/19	/19	ARIN
71.56.160.0/19	/19	ARIN
71.57.192.0/19	/19	ARIN
71.62.0.0/16	/16	ARIN
71.63.0.0/17	/17	ARIN
71.197.0.0/20	/20	ARIN
71.206.128.0/18	/18	ARIN
71.207.128.0/19	/19	ARIN
73.12.0.0/17	/17	ARIN
73.31.0.0/16	/16	ARIN
73.40.0.0/17	/17	ARIN
73.99.0.0/16	/16	ARIN
73.147.0.0/16	/16	ARIN
73.148.0.0/17	/17	ARIN
73.152.0.0/16	/16	ARIN
73.171.0.0/17	/17	ARIN
73.177.128.0/17	/17	ARIN
73.216.0.0/16	/16	ARIN
73.251.0.0/16	/16	ARIN
74.92.186.0/23	/23	ARIN
74.92.255.0/24	/24	ARIN
74.93.116.0/22	/22	ARIN
74.94.208.0/21	/21	ARIN
74.95.96.0/22	/22	ARIN
75.75.0.0/18	/18	ARIN
75.75.64.0/21	/21	ARIN
75.75.80.0/20	/20	ARIN
75.75.96.0/19	/19	ARIN
75.144.34.0/23	/23	ARIN
75.145.196.0/22	/22	ARIN
75.145.204.0/22	/22	ARIN
75.145.240.0/21	/21	ARIN
75.146.16.0/20	/20	ARIN
75.146.87.0/24	/24	ARIN
75.150.48.0/20	/20	ARIN
76.26.64.0/19	/19	ARIN
76.27.160.0/19	/19	ARIN
76.104.0.0/17	/17	ARIN
76.111.176.0/20	/20	ARIN
76.120.192.0/18	/18	ARIN
76.123.0.0/18	/18	ARIN
96.75.192.0/19	/19	ARIN
96.82.0.0/20	/20	ARIN
96.82.24.0/21	/21	ARIN
96.84.224.0/20	/20	ARIN
96.85.32.0/20	/20	ARIN
96.89.0.0/19	/19	ARIN
96.94.208.0/20	/20	ARIN
96.96.176.0/21	/21	ARIN
96.108.106.0/23	/23	ARIN
96.108.129.0/24	/24	ARIN
96.108.130.0/23	/23	ARIN
96.108.140.0/23	/23	ARIN
96.109.65.0/24	/24	ARIN
96.109.165.0/24	/24	ARIN
96.109.200.0/22	/22	ARIN
96.110.123.0/24	/24	ARIN
96.110.200.0/22	/22	ARIN
96.114.56.0/23	/23	ARIN
96.119.192.0/22	/22	ARIN
96.124.180.0/22	/22	ARIN
96.124.244.0/22	/22	ARIN
96.208.0.0/21	/21	ARIN
96.216.16.0/22	/22	ARIN
96.216.88.0/22	/22	ARIN
96.220.16.0/21	/21	ARIN
96.220.32.0/19	/19	ARIN
98.244.64.0/18	/18	ARIN
98.249.0.0/18	/18	ARIN
162.148.96.0/23	/23	ARIN
162.148.226.0/23	/23	ARIN
162.148.254.0/23	/23	ARIN
162.151.58.0/23	/23	ARIN
162.151.162.0/23	/23	ARIN
162.151.255.0/24	/24	ARIN
173.14.112.0/20	/20	ARIN
173.14.193.0/24	/24	ARIN
173.15.192.0/20	/20	ARIN
173.163.192.0/20	/20	ARIN
173.167.32.0/20	/20	ARIN
173.167.48.0/22	/22	ARIN
173.167.52.0/22	/22	ARIN
173.167.80.0/22	/22	ARIN
174.53.64.0/19	/19	ARIN
174.179.0.0/16	/16	ARIN
184.115.0.0/18	/18	ARIN
2001:558:180::/44	/44	ARIN
2001:558:230::/44	/44	ARIN
2001:558:501e::/48	/48	ARIN
2001:558:6023::/48	/48	ARIN
2001:558:6036::/48	/48	ARIN
2001:558:701a::/48	/48	ARIN
2001:558:a006::/48	/48	ARIN
2001:558:fe30::/48	/48	ARIN
2001:559:8a::/48	/48	ARIN
2001:559:c0::/48	/48	ARIN
2001:559:f7::/48	/48	ARIN
2001:559:19f::/48	/48	ARIN
2001:559:220::/48	/48	ARIN
2001:559:243::/48	/48	ARIN
2001:559:280::/48	/48	ARIN
2001:559:37d::/48	/48	ARIN
2001:559:39d::/48	/48	ARIN
2001:559:3ac::/48	/48	ARIN
2001:559:3b9::/48	/48	ARIN
2001:559:3c8::/48	/48	ARIN
2001:559:40a::/48	/48	ARIN
2001:559:42b::/48	/48	ARIN
2001:559:43b::/48	/48	ARIN
2001:559:49a::/48	/48	ARIN
2001:559:49b::/48	/48	ARIN
2001:559:4b6::/48	/48	ARIN
2001:559:53c::/48	/48	ARIN
2001:559:543::/48	/48	ARIN
2001:559:54c::/48	/48	ARIN
2001:559:54d::/48	/48	ARIN

Showing 200 of 280.

ROA-based and RPKI-valid-only prefix lists for routers are on asn.ipinfo.app.

RPKI · ASPA

Declared transit providers

No ASPA record This network has not published an ASPA object. ASPA lets a network sign the list of its transit providers, so routers can reject paths that route through anyone else (route leaks). Only a few thousand networks publish one so far, so its absence is normal.

IRR

Registered route objects

27 objects · 25 not announced

Route objects naming AS21508 as origin, across RADb, the RIR registries, ALTDB and NTTCOM. Objects that are registered but not announced come first: a stale object lets anyone who can spoof this origin through an IRR-built filter.

Prefix	Source	Description	Maintainer	Changed	Routing
24.131.0.0/20	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
67.163.96.0/19	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
67.166.160.0/19	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
67.172.192.0/19	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
67.187.0.0/19	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
68.85.226.0/24	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
68.86.14.0/24	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
68.86.24.0/24	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
68.86.124.0/22	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
68.86.172.0/22	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
71.56.160.0/19	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
71.62.0.0/16	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
71.197.0.0/20	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
71.206.128.0/18	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
71.207.128.0/19	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
74.92.186.0/23	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
74.92.255.0/24	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
74.93.116.0/22	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
74.94.208.0/21	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
74.95.96.0/22	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
75.144.34.0/23	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
75.146.16.0/20	RADB	Comcast Cable Communications, Inc.	`MAINT-AS7922`	2023-11-13	Not announced
184.115.0.0/18	ARIN	Comcast Cable Communications, LLC	`MNT-CCCS`	2025-10-15	Not announced
2001:558:a006::/48	ARIN	Comcast Cable Communications, LLC	`MNT-CCCS`	2025-10-15	Not announced
2603:308a::/32	ARIN	Comcast Cable Communications, LLC	`MNT-CCCS`	2025-10-15	Not announced
157.240.147.0/24	RADB	fzrd1	`MAINT-AS32934`	2023-11-13	Announced
157.240.148.0/24	RADB	fzrd1	`MAINT-AS32934`	2023-11-13	Announced

IRR

AS-sets

The as-set is what upstreams expand to build this network's customer filter. Sets that list AS21508 directly show who expects to carry it.

AS-set	Where	Relationship
`AS-COMCAST-IBONE`	RADB	Lists AS21508 as a direct member
`AS-COMCAST-RANS`	RADB	Lists AS21508 as a direct member
`AS7922:AS-COMCAST-RANS`	ARIN	Lists AS21508 as a direct member

RPKI from rpki-client, validated 2026-10-17 12:17 UTC. IRR from ARIN, RADB, RIPE, ALTDB, APNIC, LACNIC, NTTCOM, collected 2026-10-17. Cross-check on bgp.he.net.