IPv4 R&E Routing Table Report 22:20 GMT Fri 22 Aug, 2025 IPv4 BGP Table (R&E) as seen at ESnet. Report Website: https://bgp.nsrc.org/REN Detailed Analysis: https://bgp.nsrc.org/REN/ESnet/ Analysis Summary ---------------- BGP routing table entries examined: 18934 Prefixes after maximum aggregation (per Origin AS): 10395 Deaggregation factor: 1.82 Unique aggregates announced (without unneeded subnets): 11585 Number of IPv4 prefixes with a valid ROA: 7969 Number of IPv4 prefixes with an invalid ROA: 1 Number of IPv4 prefixes with no ROA: 10964 Total ASes present in the Internet Routing Table: 2724 Prefixes per ASN: 6.95 Origin-only ASes present in the Internet Routing Table: 2380 Origin ASes announcing only one prefix: 1061 Transit ASes present in the Internet Routing Table: 344 Transit-only ASes present in the Internet Routing Table: 48 Paths with bogon ASNs present in the IPv4 Routing Table: 0 Average AS path length visible in the Internet Routing Table: 3.9 Max AS path length visible: 15 Max AS path prepend of ASN (395156) 12 Prefixes from unregistered ASNs in the Routing Table: 34 Number of instances of unregistered ASNs: 34 Number of 32-bit ASNs allocated by the RIRs: 47246 Number of 32-bit ASNs visible in the Routing Table: 696 Prefixes from 32-bit ASNs in the Routing Table: 1887 Number of bogon 32-bit ASNs visible in the Routing Table: 0 Special use prefixes present in the Routing Table: 0 Prefixes being announced from unallocated address space: 2 Number of addresses announced to Internet: 167703552 Equivalent to 9 /8s, 254 /16s and 244 /24s Percentage of available address space announced: 4.5 Percentage of allocated address space announced: 4.5 Percentage of available address space allocated: 100.0 Percentage of address space in use by end-sites: 99.6 Total number of prefixes smaller than registry allocations: 2229 APNIC Region Analysis Summary ----------------------------- Prefixes being announced by APNIC Region ASes: 4766 Total APNIC prefixes after maximum aggregation: 2329 APNIC Deaggregation factor: 2.05 Prefixes being announced from the APNIC address blocks: 4765 Unique aggregates announced from the APNIC address blocks: 2708 APNIC Region origin ASes present in the Internet Routing Table: 578 APNIC Prefixes per ASN: 8.24 APNIC Region origin ASes announcing only one prefix: 239 APNIC Region transit ASes present in the Internet Routing Table: 50 Average APNIC Region AS path length visible: 3.7 Max APNIC Region AS path length visible: 12 Number of APNIC region 32-bit ASNs visible in the Routing Table: 231 Number of APNIC addresses announced to Internet: 35598336 Equivalent to 2 /8s, 31 /16s and 48 /24s APNIC AS Blocks 4608-4864, 7467-7722, 9216-10239, 17408-18431 (pre-ERX allocations) 23552-24575, 37888-38911, 45056-46079, 55296-56319, 58368-59391, 63488-64098, 64297-64395, 131072-155961 APNIC Address Blocks 1/8, 14/8, 27/8, 36/8, 39/8, 42/8, 43/8, 49/8, 58/8, 59/8, 60/8, 61/8, 101/8, 103/8, 106/8, 110/8, 111/8, 112/8, 113/8, 114/8, 115/8, 116/8, 117/8, 118/8, 119/8, 120/8, 121/8, 122/8, 123/8, 124/8, 125/8, 126/8, 133/8, 150/8, 153/8, 163/8, 171/8, 175/8, 180/8, 182/8, 183/8, 202/8, 203/8, 210/8, 211/8, 218/8, 219/8, 220/8, 221/8, 222/8, 223/8, ARIN Region Analysis Summary ---------------------------- Prefixes being announced by ARIN Region ASes: 8295 Total ARIN prefixes after maximum aggregation: 4609 ARIN Deaggregation factor: 1.80 Prefixes being announced from the ARIN address blocks: 8339 Unique aggregates announced from the ARIN address blocks: 5121 ARIN Region origin ASes present in the Internet Routing Table: 1275 ARIN Prefixes per ASN: 6.54 ARIN Region origin ASes announcing only one prefix: 456 ARIN Region transit ASes present in the Internet Routing Table: 152 Average ARIN Region AS path length visible: 3.8 Max ARIN Region AS path length visible: 15 Number of ARIN region 32-bit ASNs visible in the Routing Table: 229 Number of ARIN addresses announced to Internet: 72641536 Equivalent to 4 /8s, 84 /16s and 108 /24s ARIN AS Blocks 1-1876, 1902-2042, 2044-2046, 2048-2106 (pre-ERX allocations) 2138-2584, 2615-2772, 2823-2829, 2880-3153 3354-4607, 4865-5119, 5632-6655, 6912-7466 7723-8191, 10240-12287, 13312-15359, 16384-17407 18432-20479, 21504-23551, 25600-26591, 26624-27647, 29696-30719, 31744-33791 35840-36863, 39936-40959, 46080-47103 53248-55295, 62464-63487, 64198-64296, 393216-402332 ARIN Address Blocks 3/8, 4/8, 6/8, 7/8, 8/8, 9/8, 11/8, 12/8, 13/8, 15/8, 16/8, 17/8, 18/8, 19/8, 20/8, 21/8, 22/8, 23/8, 24/8, 26/8, 28/8, 29/8, 30/8, 32/8, 33/8, 34/8, 35/8, 38/8, 40/8, 44/8, 45/8, 47/8, 48/8, 50/8, 52/8, 54/8, 55/8, 56/8, 63/8, 64/8, 65/8, 66/8, 67/8, 68/8, 69/8, 70/8, 71/8, 72/8, 73/8, 74/8, 75/8, 76/8, 96/8, 97/8, 98/8, 99/8, 100/8, 104/8, 107/8, 108/8, 128/8, 129/8, 130/8, 131/8, 132/8, 134/8, 135/8, 136/8, 137/8, 138/8, 139/8, 140/8, 142/8, 143/8, 144/8, 146/8, 147/8, 148/8, 149/8, 152/8, 155/8, 156/8, 157/8, 158/8, 159/8, 160/8, 161/8, 162/8, 164/8, 165/8, 166/8, 167/8, 168/8, 169/8, 170/8, 172/8, 173/8, 174/8, 184/8, 192/8, 198/8, 199/8, 204/8, 205/8, 206/8, 207/8, 208/8, 209/8, 214/8, 215/8, 216/8, RIPE Region Analysis Summary ---------------------------- Prefixes being announced by RIPE Region ASes: 3534 Total RIPE prefixes after maximum aggregation: 2821 RIPE Deaggregation factor: 1.25 Prefixes being announced from the RIPE address blocks: 3525 Unique aggregates announced from the RIPE address blocks: 2908 RIPE Region origin ASes present in the Internet Routing Table: 653 RIPE Prefixes per ASN: 5.40 RIPE Region origin ASes announcing only one prefix: 293 RIPE Region transit ASes present in the Internet Routing Table: 102 Average RIPE Region AS path length visible: 3.7 Max RIPE Region AS path length visible: 13 Number of RIPE region 32-bit ASNs visible in the Routing Table: 151 Number of RIPE addresses announced to Internet: 53213440 Equivalent to 3 /8s, 43 /16s and 249 /24s RIPE AS Blocks 1877-1901, 2043, 2047, 2107-2136, 2585-2614 (pre-ERX allocations) 2773-2822, 2830-2879, 3154-3353, 5377-5631 6656-6911, 8192-9215, 12288-13311, 15360-16383 20480-21503, 24576-25599, 28672-29695 30720-31743, 33792-35839, 38912-39935 40960-45055, 47104-52223, 56320-58367 59392-61439, 61952-62463, 64396-64495 196608-216475 RIPE Address Blocks 2/8, 5/8, 25/8, 31/8, 37/8, 46/8, 51/8, 53/8, 57/8, 62/8, 77/8, 78/8, 79/8, 80/8, 81/8, 82/8, 83/8, 84/8, 85/8, 86/8, 87/8, 88/8, 89/8, 90/8, 91/8, 92/8, 93/8, 94/8, 95/8, 109/8, 141/8, 145/8, 151/8, 176/8, 178/8, 185/8, 188/8, 193/8, 194/8, 195/8, 212/8, 213/8, 217/8, LACNIC Region Analysis Summary ------------------------------ Prefixes being announced by LACNIC Region ASes: 1228 Total LACNIC prefixes after maximum aggregation: 465 LACNIC Deaggregation factor: 2.64 Prefixes being announced from the LACNIC address blocks: 1227 Unique aggregates announced from the LACNIC address blocks: 630 LACNIC Region origin ASes present in the Internet Routing Table: 121 LACNIC Prefixes per ASN: 10.14 LACNIC Region origin ASes announcing only one prefix: 47 LACNIC Region transit ASes present in the Internet Routing Table: 21 Average LACNIC Region AS path length visible: 4.3 Max LACNIC Region AS path length visible: 12 Number of LACNIC region 32-bit ASNs visible in the Routing Table: 57 Number of LACNIC addresses announced to Internet: 3856640 Equivalent to 0 /8s, 58 /16s and 217 /24s LACNIC AS Blocks 26592-26623, 27648-28671, 52224-53247, 61440-61951, 64099-64197, 262144-274844 + ERX transfers LACNIC Address Blocks 177/8, 179/8, 181/8, 186/8, 187/8, 189/8, 190/8, 191/8, 200/8, 201/8, AfriNIC Region Analysis Summary ------------------------------- Prefixes being announced by AfriNIC Region ASes: 1077 Total AfriNIC prefixes after maximum aggregation: 165 AfriNIC Deaggregation factor: 6.53 Prefixes being announced from the AfriNIC address blocks: 1076 Unique aggregates announced from the AfriNIC address blocks: 216 AfriNIC Region origin ASes present in the Internet Routing Table: 46 AfriNIC Prefixes per ASN: 23.39 AfriNIC Region origin ASes announcing only one prefix: 26 AfriNIC Region transit ASes present in the Internet Routing Table: 8 Average AfriNIC Region AS path length visible: 5.3 Max AfriNIC Region AS path length visible: 15 Number of AfriNIC region 32-bit ASNs visible in the Routing Table: 28 Number of AfriNIC addresses announced to Internet: 2391296 Equivalent to 0 /8s, 36 /16s and 125 /24s AfriNIC AS Blocks 36864-37887, 327680-329727 & ERX transfers AfriNIC Address Blocks 41/8, 102/8, 105/8, 154/8, 196/8, 197/8, APNIC Region per AS prefix count summary ---------------------------------------- ASN No of nets /20 equiv MaxAgg Description 2907 596 2152 459 SINET-AS Research Organization of Informa 7497 452 180 23 CSTNET-AS-AP Computer Network Information 1237 193 74 145 KREONET-AS-KR KISTI, KR 58647 182 18 2 KAGAWAU-AS Kagawa University, JP 7575 167 281 111 AARNET-AS-AP Australian Academic and Rese 4538 165 2403 80 ERX-CERNET-BKB China Education and Resear 55824 149 19 21 NKN-CORE-NW NKN Core Network, IN 4762 75 4 1 MAHIDOL-BORDER-AS Mahidol University, Tha 7560 72 5 34 CHONBUK-AS Jeonbuk National University, K 6262 63 134 56 CSIRO Commonwealth Scientific and Industr Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-APNIC ARIN Region per AS prefix count summary --------------------------------------- ASN No of nets /20 equiv MaxAgg Description 2152 584 492 99 CENIC-2152, US 2920 232 44 49 LACOE, US 376 200 162 150 RISQ-AS, CA 5786 199 16 1 UPRENET, PR 18558 140 18 5 NETBLK-RCOEK, US 81 127 471 35 NCREN, US 21976 88 34 14 NJEDGE-NET, US 237 84 542 50 MERIT-AS-14, US 1736 79 16 1 MU-AS, US 3477 77 79 36 NOAA-NWAVE, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-ARIN RIPE Region per AS prefix count summary --------------------------------------- ASN No of nets /20 equiv MaxAgg Description 680 283 1883 250 DFN Verein zur Foerderung eines Deutschen 786 189 1742 184 JANET Jisc Services Limited, GB 559 114 533 104 SWITCH Switch, Swiss Academic and Researc 8895 109 24 5 ISU Internet Services Unit ISU, SA 1103 97 1247 83 SURFNET-NL SURFnet, The Netherlands, NL 2614 92 26 69 ROEDUNET, RO 137 82 677 77 ASGARR Consortium GARR, IT 3267 80 29 69 NIKS, RU 1930 78 88 73 RCCN Fundacao para a Ciencia e a Tecnolog 553 75 366 75 BELWUE BelWue-Koordination, DE Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-RIPE LACNIC Region per AS prefix count summary ----------------------------------------- ASN No of nets /20 equiv MaxAgg Description 1916 240 177 41 Rede Nacional de Ensino e Pesquisa, BR 28391 159 10 71 Universidad Juarez Autonoma de Tabasco, M 11340 111 25 50 Red Universitaria Nacional, CL 271640 68 8 1 UNIVERSIDADE FEDERAL DE VICOSA, BR 61468 52 3 21 CEDIA, EC 19611 49 17 2 Associacao Antonio Vieira - Unisinos, BR 2715 45 99 33 Fundacao Carlos Chagas Filho de Amparo a 28614 38 2 2 Fundacao Universidade Regional de Blumena 1251 37 31 26 FUNDACAO DE AMPARO A PESQUISA DO ESTADO S 3596 37 8 4 Universidad Autonoma Metropolitana, MX Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-LACNIC AfriNIC Region per AS prefix count summary ------------------------------------------ ASN No of nets /20 equiv MaxAgg Description 36914 487 82 3 KENET-AS, KE 2018 375 318 69 TENET-1, ZA 8094 47 48 18 PUKNET, ZA 37215 40 8 1 MAREN, MW 6879 24 2 9 ENSTINET-, EG 37501 11 49 6 UOFS, ZA 327700 11 16 1 MoRENet, MZ 37654 10 1 6 RwEdNet-AS, RW 36982 8 33 8 UCT, ZA 327947 7 4 1 KNUST-, GH Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet-AFRINIC Global Per AS prefix count summary ---------------------------------- ASN No of nets /20 equiv MaxAgg Description 2907 596 2152 459 SINET-AS Research Organization of Informa 2152 584 492 99 CENIC-2152, US 36914 487 82 3 KENET-AS, KE 7497 452 180 23 CSTNET-AS-AP Computer Network Information 2018 375 318 69 TENET-1, ZA 680 283 1883 250 DFN Verein zur Foerderung eines Deutschen 1916 240 177 41 Rede Nacional de Ensino e Pesquisa, BR 2920 232 44 49 LACOE, US 376 200 162 150 RISQ-AS, CA 5786 199 16 1 UPRENET, PR Complete listing at https://bgp.nsrc.org/REN/ESnet/data-ASnet Global Per AS Maximum Aggregation summary ----------------------------------------- ASN No of nets Net Savings Description 2152 584 485 CENIC-2152, US 36914 487 484 KENET-AS, KE 7497 452 429 CSTNET-AS-AP Computer Network Information Cente 2018 375 306 TENET-1, ZA 1916 240 199 Rede Nacional de Ensino e Pesquisa, BR 5786 199 198 UPRENET, PR 2920 232 183 LACOE, US 58647 182 180 KAGAWAU-AS Kagawa University, JP 18558 140 135 NETBLK-RCOEK, US 55824 149 128 NKN-CORE-NW NKN Core Network, IN Complete listing at https://bgp.nsrc.org/REN/ESnet/data-CIDRnet List of Unregistered Origin ASNs (Global) ----------------------------------------- Bad AS Designation Net Originated Transit AS Transit AS Name 26971 UNALLOCATED 129.111.0.0/16 276 OTS-AS-276, US 26898 UNALLOCATED 131.187.248.0/22 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.248.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.249.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.250.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 131.187.251.0/24 3112 OARNET-AS-1, US 26898 UNALLOCATED 198.30.187.0/24 3112 OARNET-AS-1, US 22272 UNALLOCATED 206.208.24.0/21 6325 ILLINOIS-CENTURY, US 26898 UNALLOCATED 208.108.80.0/20 3112 OARNET-AS-1, US 26898 UNALLOCATED 208.108.80.0/24 3112 OARNET-AS-1, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-badAS Advertised Unallocated Addresses -------------------------------- Unassigned Network ASN Information AS Name 164.160.192.0/21 Origin: 37661 NRaE1-AS, NG 164.160.192.0/21 Transit: 37288 WACREN, SN 203.9.156.0/24 Origin: 1851 ADELAIDE-UNIVERSITY-AS-AP The University 203.9.156.0/24 Transit: 7575 AARNET-AS-AP Australian Academic and Res Complete listing at https://bgp.nsrc.org/REN/ESnet/data-add-IANA Number of prefixes announced per prefix length (Global) ------------------------------------------------------- /1:0 /2:0 /3:0 /4:0 /5:0 /6:0 /7:0 /8:0 /9:0 /10:0 /11:0 /12:0 /13:0 /14:33 /15:114 /16:1923 /17:420 /18:451 /19:590 /20:849 /21:825 /22:1426 /23:1574 /24:10729 /25:0 /26:0 /27:0 /28:0 /29:0 /30:0 /31:0 /32:0 Advertised prefixes smaller than registry allocations ----------------------------------------------------- ASN No of nets Total ann. Description 36914 474 487 KENET-AS, KE 8895 106 109 ISU Internet Services Unit ISU, SA 2152 67 584 CENIC-2152, US 3267 35 80 NIKS, RU 37215 34 40 MAREN, MW 200521 34 58 SEAP-AGE, ES 28614 32 38 Fundacao Universidade Regional de Blumenau, BR 46115 32 35 LUTHER, US 25977 30 44 HCCS, US 27609 29 45 USC-UNIVERSITY-HOSPITAL, US Complete listing at https://bgp.nsrc.org/REN/ESnet/data-sXXas-nos Number of /24s announced per /8 block (Global) ---------------------------------------------- 1:2 5:16 8:5 12:2 14:93 18:39 23:11 24:3 31:1 35:4 37:14 38:13 41:159 42:18 44:5 45:40 46:5 47:1 49:12 50:4 52:1 58:14 59:20 60:6 61:3 62:6 63:36 64:47 65:21 66:56 67:44 68:19 69:19 70:2 71:1 72:8 74:52 76:27 77:9 78:3 79:9 80:13 81:27 82:5 83:8 84:5 85:48 86:3 87:1 89:9 91:41 92:2 93:14 94:2 95:2 96:5 97:1 98:2 101:3 102:11 103:341 104:74 107:2 108:8 109:7 111:20 113:30 114:21 116:7 117:61 118:33 119:31 121:23 122:8 123:8 124:42 125:5 128:59 129:47 130:98 131:69 132:53 133:156 134:109 136:200 137:106 138:11 139:5 140:32 141:4 142:26 143:26 144:37 145:2 146:137 147:27 148:201 149:11 150:36 151:12 152:124 153:15 154:40 155:84 156:130 157:23 158:26 159:117 160:32 161:29 162:30 163:70 164:9 165:43 166:2 167:28 168:96 169:6 170:23 171:1 172:1 173:6 174:1 175:16 177:5 179:13 180:16 181:1 182:12 184:1 185:50 186:3 187:22 188:16 190:17 191:13 192:1393 193:274 194:122 195:72 196:147 197:355 198:523 199:247 200:299 201:20 202:622 203:451 204:400 205:181 206:201 207:319 208:63 209:143 210:219 211:4 212:148 213:4 216:88 217:23 218:22 219:6 220:16 222:4 223:5 End of report