21369 SEMA-UK-AS, GB
Adjacency: 4 Upstream: 4 Downstream: 0
Upstream Adjacent AS list
AS702 UUNET - Verizon Business, US
AS2856 BT-UK-AS BTnet UK Regional network, GB
AS198949 RADWARE, IL
AS8220 COLT COLT Technology Services Group Limited, GB
Rank AS Type Originate Addr Space (pfx) Transit Addr space (pfx) Description 7946 AS21369 ORIGIN Originate: 16128 /18.02 Transit: 0 /0.00 SEMA-UK-AS, GB
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 % 3860 AS21369 SEMA-UK-AS, GB 46 26 13 33 13 28.26% Prefix AS Path Aggregation Suggestion 157.203.6.0/23 4777 2516 8220 21369 21369 157.203.6.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.6.0/24 (4608 7575 2914 198949 21369) and 157.203.7.0/24 (4608 7575 2914 198949 21369) 157.203.6.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.7.0/24 (4608 7575 2914 198949 21369) 157.203.7.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.6.0/24 (4608 7575 2914 198949 21369) 157.203.36.0/23 4777 2497 5400 2856 21369 21369 157.203.36.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.36.0/24 (4608 7575 2914 198949 21369) and 157.203.37.0/24 (4608 7575 2914 198949 21369) 157.203.36.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.37.0/24 (4608 7575 2914 198949 21369) 157.203.37.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.36.0/24 (4608 7575 2914 198949 21369) 157.203.40.0/23 4777 2497 5400 2856 21369 21369 157.203.40.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.40.0/24 (4608 7575 2914 198949 21369) and 157.203.41.0/24 (4608 7575 2914 198949 21369) 157.203.40.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.41.0/24 (4608 7575 2914 198949 21369) 157.203.41.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.40.0/24 (4608 7575 2914 198949 21369) 157.203.42.0/23 4777 2497 5400 2856 21369 21369 157.203.42.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.42.0/24 (4608 7575 2914 198949 21369) and 157.203.43.0/24 (4608 7575 2914 198949 21369) 157.203.42.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.43.0/24 (4608 7575 2914 198949 21369) 157.203.43.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.42.0/24 (4608 7575 2914 198949 21369) 157.203.48.0/23 4777 2497 5400 2856 21369 21369 157.203.48.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.48.0/24 (4608 7575 2914 198949 21369) and 157.203.49.0/24 (4608 7575 2914 198949 21369) 157.203.48.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.49.0/24 (4608 7575 2914 198949 21369) 157.203.49.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.48.0/24 (4608 7575 2914 198949 21369) 157.203.52.0/23 4777 2516 8220 21369 21369 157.203.52.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.52.0/24 (4608 7575 2914 198949 21369) and 157.203.53.0/24 (4608 7575 2914 198949 21369) 157.203.52.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.53.0/24 (4608 7575 2914 198949 21369) 157.203.53.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.52.0/24 (4608 7575 2914 198949 21369) 157.203.56.0/23 4777 2516 8220 21369 21369 157.203.56.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.56.0/24 (4608 7575 2914 198949 21369) and 157.203.57.0/24 (4608 7575 2914 198949 21369) 157.203.56.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.57.0/24 (4608 7575 2914 198949 21369) 157.203.57.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.56.0/24 (4608 7575 2914 198949 21369) 157.203.58.0/23 4777 2516 8220 21369 21369 157.203.59.0/24 4608 7575 2914 198949 21369 157.203.60.0/23 4777 2516 8220 21369 21369 157.203.60.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.60.0/24 (4608 7575 2914 198949 21369) and 157.203.61.0/24 (4608 7575 2914 198949 21369) 157.203.60.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.61.0/24 (4608 7575 2914 198949 21369) 157.203.61.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.60.0/24 (4608 7575 2914 198949 21369) 157.203.62.0/23 4777 2516 8220 21369 21369 157.203.62.0/24 4608 7575 2914 198949 21369 157.203.92.0/23 4777 2516 8220 21369 21369 157.203.120.0/23 4777 2497 5400 2856 21369 21369 157.203.120.0/24 4608 7575 2914 198949 21369 157.203.176.0/23 4777 2497 5400 2856 21369 21369 157.203.176.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.176.0/24 (4608 7575 2914 198949 21369) and 157.203.177.0/24 (4608 7575 2914 198949 21369) 157.203.176.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.177.0/24 (4608 7575 2914 198949 21369) 157.203.177.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.176.0/24 (4608 7575 2914 198949 21369) 157.203.178.0/23 4777 2497 5400 2856 21369 21369 157.203.178.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.178.0/24 (4608 7575 2914 198949 21369) and 157.203.179.0/24 (4608 7575 2914 198949 21369) 157.203.178.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.179.0/24 (4608 7575 2914 198949 21369) 157.203.179.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.178.0/24 (4608 7575 2914 198949 21369) 157.203.180.0/23 4777 2516 8220 21369 21369 157.203.180.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.180.0/24 (4608 7575 2914 198949 21369) and 157.203.181.0/24 (4608 7575 2914 198949 21369) 157.203.180.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.181.0/24 (4608 7575 2914 198949 21369) 157.203.181.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.180.0/24 (4608 7575 2914 198949 21369) 157.203.242.0/23 4777 2516 8220 21369 21369 21369 157.203.242.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.242.0/24 (4608 7575 2914 198949 21369) and 157.203.243.0/24 (4608 7575 2914 198949 21369) 157.203.242.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.243.0/24 (4608 7575 2914 198949 21369) 157.203.243.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.242.0/24 (4608 7575 2914 198949 21369) 157.203.254.0/23 4777 2497 5400 2856 21369 21369 157.203.254.0/23 4608 7575 2914 198949 21369 + Announce - aggregate of 157.203.254.0/24 (4608 7575 2914 198949 21369) and 157.203.255.0/24 (4608 7575 2914 198949 21369) 157.203.254.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.255.0/24 (4608 7575 2914 198949 21369) 157.203.255.0/24 4608 7575 2914 198949 21369 - Withdrawn - aggregated with 157.203.254.0/24 (4608 7575 2914 198949 21369)
Advertisements that are fragments of the original RIR allocation (more specifics) originated by this AS.
AS21369 46 More Specifics 46 Total Advertisements SEMA-UK-AS, GB
157.203.6.0/23 157.203.0.0/16
157.203.6.0/24 157.203.0.0/16
157.203.7.0/24 157.203.0.0/16
157.203.36.0/23 157.203.0.0/16
157.203.36.0/24 157.203.0.0/16
157.203.37.0/24 157.203.0.0/16
157.203.40.0/23 157.203.0.0/16
157.203.40.0/24 157.203.0.0/16
157.203.41.0/24 157.203.0.0/16
157.203.42.0/23 157.203.0.0/16
157.203.42.0/24 157.203.0.0/16
157.203.43.0/24 157.203.0.0/16
157.203.48.0/23 157.203.0.0/16
157.203.48.0/24 157.203.0.0/16
157.203.49.0/24 157.203.0.0/16
157.203.52.0/23 157.203.0.0/16
157.203.52.0/24 157.203.0.0/16
157.203.53.0/24 157.203.0.0/16
157.203.56.0/23 157.203.0.0/16
157.203.56.0/24 157.203.0.0/16
157.203.57.0/24 157.203.0.0/16
157.203.58.0/23 157.203.0.0/16
157.203.59.0/24 157.203.0.0/16
157.203.60.0/23 157.203.0.0/16
157.203.60.0/24 157.203.0.0/16
157.203.61.0/24 157.203.0.0/16
157.203.62.0/23 157.203.0.0/16
157.203.62.0/24 157.203.0.0/16
157.203.92.0/23 157.203.0.0/16
157.203.120.0/23 157.203.0.0/16
157.203.120.0/24 157.203.0.0/16
157.203.176.0/23 157.203.0.0/16
157.203.176.0/24 157.203.0.0/16
157.203.177.0/24 157.203.0.0/16
157.203.178.0/23 157.203.0.0/16
157.203.178.0/24 157.203.0.0/16
157.203.179.0/24 157.203.0.0/16
157.203.180.0/23 157.203.0.0/16
157.203.180.0/24 157.203.0.0/16
157.203.181.0/24 157.203.0.0/16
157.203.242.0/23 157.203.0.0/16
157.203.242.0/24 157.203.0.0/16
157.203.243.0/24 157.203.0.0/16
157.203.254.0/23 157.203.0.0/16
157.203.254.0/24 157.203.0.0/16
157.203.255.0/24 157.203.0.0/16
whois: 402332
IANA has recorded AS21369 as originally allocated by
/usr/bin/whois -h jwhois.apnic.netr "AS21369\n % This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See https://docs.db.ripe.net/terms-conditions.html
% Note: this output has been filtered.
% Information related to 'AS21281 - AS21390'
as-block: AS21281 - AS21390
descr: RIPE NCC ASN block
remarks: These AS Numbers are assigned to network operators in the RIPE NCC service region.
mnt-by: RIPE-NCC-HM-MNT
created: 2018-11-22T15:27:28Z
last-modified: 2018-11-22T15:27:28Z
source: RIPE
% Information related to 'AS21369'
% Abuse contact for 'AS21369' is 'uk.abuse@atos.net'
aut-num: AS21369
as-name: SEMA-UK-AS
org: ORG-AISU1-RIPE
remarks: Will advertise network 192.12.43.0/24
remarks: ------------------------------------------------------
remarks: *
remarks: Verizon Peering
remarks: *
remarks: ------------------------------------------------------
import: from AS702 action pref=100; accept ANY
export: to AS702 announce AS21369
remarks: ------------------------------------------------------
remarks: *
remarks: Level3 Peering
remarks: *
remarks: ------------------------------------------------------
import: from AS3356 action pref=100; accept ANY
import: from AS3549 action pref=100; accept ANY
export: to AS3356 announce AS21369
export: to AS3549 announce AS21369
remarks: ------------------------------------------------------
remarks: *
remarks: Zayo Peering
remarks: *
remarks: ------------------------------------------------------
import: from AS6461 action pref=100; accept ANY
export: to AS6461 announce AS21369
remarks: ------------------------------------------------------
remarks: *
remarks: ConvergenceGroup Peering
remarks: *
remarks: ------------------------------------------------------
import: from AS41811 action pref=100; accept ANY
export: to AS41811 announce AS21369
remarks: ------------------------------------------------------
remarks: *
remarks: BGP Off-ramping Peering
remarks: *
remarks: ------------------------------------------------------
import: from AS198949 action pref=100; accept ANY
export: to AS198949 announce AS21369
remarks: ------------------------------------------------------
remarks: *
remarks: Legacy peerings for review
remarks: *
remarks: ------------------------------------------------------
export: to AS8918 announce AS21369
import: from AS8918 action pref=100; accept ANY
import: from AS2856 action pref=100; accept ANY
default: to AS2856 action pref=100; networks ANY
remarks: ------------------------------------------------------
remarks: *
remarks: Last modified by Shared Services 03-01-2023
admin-c: ATOS5-RIPE
tech-c: ATOS5-RIPE
status: ASSIGNED
mnt-by: RIPE-NCC-END-MNT
mnt-by: SEMA-UK-AS-MNT
created: 2001-11-15T09:27:21Z
last-modified: 2023-01-03T10:00:37Z
source: RIPE
organisation: ORG-AISU1-RIPE
org-name: Atos IT Services UK Ltd
country: GB
org-type: LIR
address: Second Floor, Mid City Place,
71 High Holborn,
address: WC1V 6EA
address: London
address: UNITED KINGDOM
phone: +448007833040
fax-no: +441616018842
reg-nr: 1245534
admin-c: ATOS5-RIPE
tech-c: ATOS5-RIPE
abuse-c: AA30342-RIPE
mnt-by: SEMA-UK-AS-MNT
mnt-ref: SEMA-UK-AS-MNT
mnt-ref: RIPE-NCC-HM-MNT
mnt-by: RIPE-NCC-HM-MNT
created: 2013-05-30T09:12:57Z
last-modified: 2026-04-29T05:34:04Z
source: RIPE # Filtered
role: ATOS Admin
address: 3300 Solihull Parkway
address: Birmingham Business Park
address: B37 7YQ
abuse-mailbox: UK.Abuse@atos.net
nic-hdl: ATOS5-RIPE
mnt-by: SEMA-UK-AS-MNT
created: 2013-10-05T00:51:50Z
last-modified: 2013-10-05T03:40:17Z
source: RIPE # Filtered
% This query was served by the RIPE Database Query Service version 1.122 (ABERDEEN)