nanog mailing list archives

GTT blocking IPv4 address 128.31.0.39


From: Neel Chauhan <neel () neelc org>
Date: Tue, 03 Jan 2023 19:49:17 -0800

Hi,

I am a customer of ReliableSite in their New Jersey location, and RS uses GTT as a transit ISP, along with Tata and Comcast.

GTT appears to be blocking the IPv4 address 128.31.0.39, and RS' BGP uses GTT for 128.31.0.39.

neel@t1:~ % traceroute 128.31.0.39
traceroute to 128.31.0.39 (128.31.0.39), 64 hops max, 40 byte packets
 1  45.150.XXX.1 (45.150.XXX.1)  4.828 ms  4.557 ms  5.916 ms
 2  * * *
^C
neel@t1:~ %

Hop #2 which is generally the transit provider, GTT (which handles this route).

Note: 45.150.XXX.1 is because it's a subnet I brought in, this is the only ReliableSite hop.

The 128.31.0.0/24 doesn't appear to be blocked as a whole, only that 128.31.0.39. See below:

neel@t1:~ % traceroute 128.31.0.1
traceroute to 128.31.0.1 (128.31.0.1), 64 hops max, 40 byte packets
 1  45.150.XXX.1 (45.150.XXX.1)  0.241 ms  0.220 ms  9.362 ms
2 ae9-300.cr2-nyc4.ip4.gtt.net (209.120.147.121) 1.605 ms 0.853 ms 1.173 ms 3 ae3.cr1-nyc2.ip4.gtt.net (89.149.129.194) 5.488 ms 6.471 ms 1.451 ms 4 be3088.ccr31.jfk04.atlas.cogentco.com (154.54.11.57) 1.604 ms 1.726 ms * 5 be3363.ccr42.jfk02.atlas.cogentco.com (154.54.3.125) 1.802 ms 1.771 ms 1.708 ms 6 be3472.ccr32.bos01.atlas.cogentco.com (154.54.46.33) 7.082 ms 7.268 ms 7.249 ms
 7  38.104.186.186 (38.104.186.186)  7.017 ms  7.247 ms  6.987 ms
8 dmz-rtr-1-external-rtr-3.mit.edu (18.0.161.13) 7.010 ms 7.001 ms 6.996 ms
 9  dmz-rtr-2-dmz-rtr-1-2.mit.edu (18.0.162.6)  7.033 ms  7.294 ms
    dmz-rtr-2-dmz-rtr-1-1.mit.edu (18.0.161.6)  7.073 ms
10 guest.default.csail.mit.edu (128.31.0.1) 9.011 ms 7.484 ms 7.551 ms
neel@t1:~ %

As you can see here, GTT handles other 128.31.0.39 IPs fine as seen in hop #2.

ReliableSite says they don't block the IP address, but I don't have any contact at GTT or MIT.

My home ISP, Lumen/CenturyLink/Level 3 does not block 128.31.0.39.

128.31.0.39 is a Tor directory authority IP, which is usually a phonebook of Tor relays. There are 9 in the world and the other 8 are unblocked from ReliableSite.

Yes, I know Tor is all this 'bad stuff' but the reality is that 99% of Tor users use it like a VPN, speaking as a Tor exit operator and code contributor myself. Exit abuse complaints were super common 5-8 years ago but are now super rare.

If someone works at GTT, can 128.31.0.39 be unblocked?

Best,

-Neel

---

https://www.neelc.org


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