I have an organization which I allocated 147.237.0.0/16 from my country block. They then wanted to subnet and hand out /24s and /23s to the dozens of offices they have scattered thru the country and to allow each office to connect to whatever ISP they wish. I told them that Sprint would block the announcements of /24s and the like when coming from 147.237.0.0. They said, then why does Sprint allow its customers to announce /24s from their nets? They gave me as examples: 148.212.0.0 and 145.248.0.0. I checked and sure enough here is what I found: *>i148.212.1.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.2.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.3.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.4.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.5.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.6.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.7.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.8.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.9.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.10.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.11.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.12.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.13.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.14.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.15.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.16.0/20 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.32.0/20 192.121.156.41 100 0 1800 1239 1791 1292 i I didn't have a good answer. Can anyone tell me what I should tell this organization? Thanks, Hank
On Feb 19, 1997, Hank Nussbacher wrote:
I have an organization which I allocated 147.237.0.0/16 from my country block. They then wanted to subnet and hand out /24s and /23s to the dozens of offices they have scattered thru the country and to allow each office to connect to whatever ISP they wish. I told them that Sprint would block the announcements of /24s and the like when coming from 147.237.0.0.
They said, then why does Sprint allow its customers to announce /24s from their nets? They gave me as examples: 148.212.0.0 and 145.248.0.0. I checked and sure enough here is what I found:
Sprint only applies the prefix length filters to external peers. All of Sprint's external peers (as far as I know) peer with AS1239, and the customers peer with other ASes (such as 1791). My best guess is that AS1292 has transit from Sprint, which means they can announce whatever they want into them. Alec -- +------------------------------------+--------------------------------------+ |Alec Peterson - ahp@hilander.com | Erols Internet Services, INC. | |Network Engineer | Springfield, VA. | +------------------------------------+--------------------------------------+
Hank Nussbacher writes:
I have an organization which I allocated 147.237.0.0/16 from my country block. They then wanted to subnet and hand out /24s and /23s to the dozens of offices they have scattered thru the country and to allow each office to connect to whatever ISP they wish. I told them that Sprint would block the announcements of /24s and the like when coming from 147.237.0.0.
They said, then why does Sprint allow its customers to announce /24s from their nets? They gave me as examples: 148.212.0.0 and 145.248.0.0. I checked and sure enough here is what I found:
Sprint's customers pay them to announce their routes. If someone else doesn't like it, they should filter - like AGIS has done. -Hank
*>i148.212.1.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.2.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.3.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.4.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.5.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.6.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.7.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.8.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.9.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.10.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.11.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.12.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.13.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.14.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.15.0/24 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.16.0/20 192.121.156.41 100 0 1800 1239 1791 1292 i *>i148.212.32.0/20 192.121.156.41 100 0 1800 1239 1791 1292 i
I didn't have a good answer. Can anyone tell me what I should tell this organization?
Thanks, Hank
They said, then why does Sprint allow its customers to announce /24s from their nets? They gave me as examples: 148.212.0.0 and 145.248.0.0. I checked and sure enough here is what I found:
...
I didn't have a good answer. Can anyone tell me what I should tell this organization?
That, among other things, Sprint is not the only NSP that filters. randy
participants (4)
-
Alec H. Peterson -
Hank Nussbacher -
Henry Kilmer -
randy＠psg.com