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AS37133Airtel Tanzania

TanzaniaRegistryAFRINICTypeEyeball

As of 23rd October 2026, AS37133 (Airtel Tanzania), an access network registered in Tanzania with AFRINIC, originates 96 IPv4 prefixes covering 89.1k addresses and 1 IPv6 prefix. By IPv4 address space that makes it the 2,563rd-largest of the 79,659 networks we see originating IPv4, and the 4th-largest of 104 in Tanzania. It is seen behind 2 upstream networks, most often AS327708 (Airtel Rwanda Ltd) and AS37440 (Airtel Malawi Ltd), and in front of 13 downstream networks. None of its announcements have a valid RPKI ROA. 75% of its routes reach at least 90% of full-feed peers, and 24 prefixes are also originated by another network.

At a glance

IPv4 prefixes

96

IPv6 prefixes

1

IPv4 addresses

89.1k

IPv6 /64s

4.3B

Upstream graph

The networks AS37133 is seen behind, one and two hops out, drawn from real AS paths.

AS37133Toward the internet core
Upstream graph for AS37133: 4 neighbouring networks observed beyond it across 2 levels. The same networks are listed in the tables below.AS37133Airtel TanzaniaThis networkAS37440Airtel Malawi LtdAS327708Airtel Rwanda LtdAS2914NTT America, Inc.AS37100SEACOM Limited

Networks observed one and two hops upstream of AS37133 in real AS paths. A thicker line means more vantage points saw that adjacency, so weight tracks how well attested it is — not how much traffic it carries. Adjacency is an observation; whether it is a transit purchase or a settlement-free peering is an inference, and is labelled as one wherever we show it.

Neighbouring networks

35

adjacent networks

Upstreams
26%
Peers
2057%
Downstreams
1337%

Networks carrying this one's traffic toward the rest of the internet.

Upstreams of AS37133
NetworkCountryRelationshipPathsVantage pts
AS327708Airtel Rwanda LtdRWPeer10,657140
AS37440Airtel Malawi LtdMWPeer6138

Prefixes

All 97

The largest blocks AS37133 originates, widest first.

Largest prefixes originated by AS37133
PrefixAddressesVisibility
156.158.0.0/1732.8k76/77
156.156.128.0/198.2k76/77
41.75.208.0/204.1k77/77
197.158.192.0/204.1k23/77
197.158.208.0/204.1k30/77
197.158.224.0/204.1k30/77
197.186.72.0/212k76/77
41.75.216.0/221k77/77
41.75.220.0/221k76/77
197.186.28.0/221k76/77

Routing health

How AS37133's own announcements validate against RPKI and how far they propagate. The same measures for the whole routing table are on the routing table in numbers.

RPKI origin validation

  • Valid0.0%0
  • Invalid0.0%0
  • No ROA100.0%97

Propagation

  • Globally propagated90% of full-feed peers or more75.3%73
  • Partially propagated40% to 90%1.0%1
  • Seen by few peersUnder 40%23.7%23

Prefix sizes

IPv4 — 96 prefixes

IPv6 — 1 prefixes

  • /324.3B × /64100.0%1

Recent changes

Announcements that started or stopped since 23rd Sept 2026.

43 announced and 19 withdrawn in all; the most recent are shown.

Routing data derived from RouteViews MRT archives, BGPKIT relationship inference and public registry data.