Did some investigation and found that some IP range have better performance to Singtel
202.184.100.xxx

MTR Result
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BGP from Singtel looking glass
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BGP routing table entry for 202.184.96.0/19, version 19581762
Paths: (2 available, best #1, table default)
Not advertised to any peer
Refresh Epoch 1
9930
203.208.131.162 (metric 10024) from 202.160.242.7 (202.160.242.7)
Origin IGP, localpref 500, valid, internal, best
Community: ...
Originator: 202.160.242.134, Cluster list: 202.160.242.7
rx pathid: 0, tx pathid: 0x0
Updated on Apr 1 2024 12:14:00 SGT
Refresh Epoch 1
9930
203.208.131.162 (metric 10024) from 202.160.242.50 (202.160.242.50)
Origin IGP, localpref 500, valid, internal
Community: ...
Originator: 202.160.242.134, Cluster list: 202.160.242.7
rx pathid: 0, tx pathid: 0
Updated on Mar 18 2024 16:04:40 SGT
202.184.169.xxx

MTR Result
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BGP from Singtel looking glass
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BGP routing table entry for 202.186.0.0/15, version 76976587
Paths: (2 available, best #2, table default)
Not advertised to any peer
Refresh Epoch 1
2914 9930
203.208.178.229 (metric 10073) from 202.160.242.7 (202.160.242.7)
Origin IGP, metric 0, localpref 300, valid, internal
Community: ...
Originator: 202.160.242.28, Cluster list: 202.160.242.7
rx pathid: 0, tx pathid: 0
Updated on May 8 2024 18:15:52 SGT
Refresh Epoch 1
6453 9930
63.243.188.4 (metric 10063) from 202.160.242.50 (202.160.242.50)
Origin IGP, metric 0, localpref 300, valid, internal, best
Community: ...
Originator: 202.160.242.69, Cluster list: 202.160.242.7
rx pathid: 0, tx pathid: 0x0
Updated on Mar 18 2024 16:05:15 SGT
Comparing the bgp result from Singtel to the 2 IP range. Kinda explain the performance differences as it is routed through either NTT or TATA instead of a direct route.
| Attribute | 202.184.96.0/19 Path 1 | 202.184.96.0/19 Path 2 | 202.186.0.0/15 Path 1 | 202.186.0.0/15 Path 2 |
| AS Path | 9930 | 9930 | 2914 9930 (NTT) | 6453 9930 (TATA) |
| Next-Hop | 203.208.131.162 | 203.208.131.162 | 203.208.178.229 | 63.243.188.4 |
| Best Path | Yes | No | No | Yes |
Just for reference purpose.