Hello NANOG, I’m a researcher and I was trying to understand the data I collected from some BGP Looking Glasses. Basically, I was hoping to see if BGP records can tell me where my university’s provider (AS3701) is peering with its providers. I issued two BGP queries to Level3’s LGs, one in Seattle and one in Amsterdam for my school’s prefix. My strong guess was that our provider (AS3701) peers with Level3 in Seattle. I was hoping to conclude something like this: if the peering occurs in Seattle, the Seattle LG should reveal it, but Amsterdam should not. AS3701 is Nero (Network for Education and Research in Oregon) which I assume is a small regional AS. I don't think Nero peers with Level3 in Amsterdam, however, I get this AS for my next hop even when I issue the command from Amsterdam. On the other hand “car1.Sacramento1” suggests that the peering happens in Sacramento. This result makes me think what I get is from a combination of iBGP and eBGP, which is also apparent from “Internal/External” keywords in the data. My main issue is that the keywords are not always available. In some other LG I just get a next hop IP and an AS path. How can I make sure that the peering information comes from an eBGP peering? I think the next hop IP might be the answer, right? I included the results of the command for both LGs here, hopefully somebody could explain to me ------------------------------------------------- Route results for 128.223.0.0/16 from Amsterdam, Netherlands BGP routing table entry for 128.223.0.0/16 Paths: (2 available, best #1) 3701 3582 AS-path translation: { OREGONUNIV UONET } car1.Sacramento1 (metric 58341) Origin IGP, metric 0, localpref 100, valid, internal, best Community: North_America Lclprf_100 Level3_Customer United_States Sacramento Originator: car1.Sacramento1 3701 3582 AS-path translation: { OREGONUNIV UONET } car1.Sacramento1 (metric 58341) Origin IGP, metric 0, localpref 100, valid, internal Community: North_America Lclprf_100 Level3_Customer United_States Sacramento Originator: car1.Sacramento1 ------------------------------------------------- Route results for 128.223.6.81/16 from Seattle, WA BGP routing table entry for 128.223.0.0/16 Paths: (4 available, best #3) 3701 3582 AS-path translation: { OREGONUNIV UONET } 4.53.150.46 from 4.53.150.46 (ptck-core1-gw.nero.net) Origin IGP, localpref 90, valid, external Community: North_America Lclprf_90 Level3_Customer United_States Seattle Level3:11847 3701 3582, (received-only) AS-path translation: { OREGONUNIV UONET } 4.53.150.46 from 4.53.150.46 (ptck-core1-gw.nero.net) Origin IGP, localpref 100, valid, external Community: Level3:90 3701 3582 AS-path translation: { OREGONUNIV UONET } car1.Sacramento1 (metric 34363) Origin IGP, metric 0, localpref 100, valid, internal, best Community: North_America Lclprf_100 Level3_Customer United_States Sacramento Originator: car1.Sacramento1 3701 3582 AS-path translation: { OREGONUNIV UONET } car1.Sacramento1 (metric 34363) Origin IGP, metric 0, localpref 100, valid, internal Community: North_America Lclprf_100 Level3_Customer United_States Sacramento Originator: car1.Sacramento1 Best Regards Reza Motamedi (R.M) Graduate Research Fellow Computer and Information Science University of Oregon