--- title: 'Telekom and Cloudflare' url: 'https://gerfficient.com/en/home/telekom-and-cloudflare' markdown: 'https://gerfficient.com/en/home/telekom-and-cloudflare.md' lang: en date: '2024-12-03' description: 'My servers are connected to domains via a Cloudflare tunnel and thus accessible from the Internet. I noticed that access to my websites has become extremely slow. However, the problem only occurred from time to time. I could not determine exactly who was responsible for the slowdown. However, I fou…' --- # Telekom and Cloudflare ### 03. Dec. 2024 My servers are connected to domains via a Cloudflare tunnel and thus accessible from the Internet. I noticed that access to my websites has become extremely slow. However, the problem only occurred from time to time. I could not determine exactly who was responsible for the slowdown. However, I found that the problem only occurs when accessing from an Internet connection provided by Deutsche Telekom.[1](#fn:1) After some research, it seems that there are problems between Cloudflare and Deutsche Telekom, and for this reason, Internet traffic is routed in such a way that it does not take the shortest route to the servers, but is first routed across the Atlantic and then back again. I was able to easily verify this fact with `traceroute`. In order to reach a website via a connected domain, the (DNS) requests have to be routed accordingly, and how they are routed becomes visible with `traceroute`: ```bash $ traceroute zangs.com traceroute: Warning: zangs.com has multiple addresses; using 104.21.64.1 traceroute to zangs.com (104.21.64.1), 64 hops max, 40 byte packets 1 fritz.box (192.168.1.1) 5.130 ms 4.936 ms 6.522 ms 2 p3e9bf29f.dip0.t-ipconnect.de (62.155.242.159) 15.971 ms 10.540 ms 13.028 ms 3 nyc-sb6-i.nyc.us.net.dtag.de (62.154.5.202) 105.114 ms 102.245 ms 171.182 ms 4 nyc-sb6-i.nyc.us.net.dtag.de (62.154.5.202) 104.956 ms 102.469 ms 328.916 ms 5 80.156.160.213 (80.156.160.213) 112.465 ms 106.346 ms 108.509 ms 6 if-ae-0-2.tcore3.njy-newark.as6453.net (216.6.90.14) 166.028 ms 280.382 ms 110.772 ms 7 66.198.70.2 (66.198.70.2) 122.046 ms 237.385 ms 104.912 ms 8 162.158.61.109 (162.158.61.109) 105.668 ms 162.158.61.113 (162.158.61.113) 116.404 ms 133.956 ms 9 104.21.64.1 (104.21.64.1) 244.904 ms 107.535 ms 107.440 ms ``` Here you can clearly see that the Internet gateway forwards to `t-ipconnect.de` which routes to `nyc.us.net.dtag.de`, which according to the URL is in New York City. This results in a significant delay of more than 100 ms, and makes accessing my website `zangs.com` correspondingly slower. What makes things even stranger is that my website `gerfficient.com` is set up with Cloudflare Pro and is redirected from the gateway to `m.de.net.dtag.de`, which, according to the URL, is in Munich[2](#fn:2): ```bash $ traceroute gerfficient.com traceroute: Warning: gerfficient.com has multiple addresses; using 104.26.15.172 traceroute to gerfficient.com (104.26.15.172), 64 hops max, 40 byte packets 1 fritz.box (192.168.2.1) 5.557 ms 6.467 ms 5.761 ms 2 p3e9bf29f.dip0.t-ipconnect.de (62.155.242.159) 14.157 ms 14.897 ms 357.228 ms 3 m-ef2-i.m.de.net.dtag.de (62.153.181.22) 11.980 ms 11.637 ms 11.254 ms 4 80.150.168.185 (80.150.168.185) 16.521 ms 17.300 ms 695.404 ms 5 cloudflare-gw.cr0-muc1.ip4.gtt.net (141.136.100.98) 12.903 ms 15.582 ms 29.041 ms 6 104.26.15.172 (104.26.15.172) 15.122 ms 12.466 ms 16.446 ms ``` And a check of the above, but from a different location that is also connected to the Internet via Deutsche Telekom, leads to the same result: ```bash $ mtr -r gerfficient.com Start: 2024-12-03T10:36:38+0100 HOST: 215f4efa5a56 Loss% Snt Last Avg Best Wrst StDev 1.|-- 172.19.0.1 0.0% 10 0.1 0.1 0.1 0.1 0.0 2.|-- 192.168.1.1 0.0% 10 1.0 1.1 1.0 1.5 0.2 3.|-- p3e9bf208.dip0.t-ipconnec 0.0% 10 5.7 5.8 5.4 6.5 0.3 4.|-- nyc-sb6-i.NYC.US.NET.DTAG 0.0% 10 96.4 111.9 96.4 151.9 20.4 5.|-- 80.156.160.213 0.0% 10 144.3 109.4 94.9 144.3 14.7 6.|-- if-ae-0-2.tcore3.njy-newa 0.0% 10 100.3 100.1 99.6 100.8 0.4 7.|-- 66.198.70.2 0.0% 10 109.8 106.0 101.9 113.4 4.5 8.|-- 162.158.61.113 0.0% 10 124.7 116.2 102.3 147.6 16.4 9.|-- 188.114.96.3 0.0% 10 116.4 113.2 102.1 154.6 17.1 $ mtr -r zangs.com Start: 2024-12-03T10:38:04+0100 HOST: 215f4efa5a56 Loss% Snt Last Avg Best Wrst StDev 1.|-- 172.19.0.1 0.0% 10 0.1 0.1 0.1 0.1 0.0 2.|-- 192.168.1.1 0.0% 10 1.1 5.6 0.9 28.2 9.7 3.|-- p3e9bf208.dip0.t-ipconnec 0.0% 10 37.2 13.9 5.0 48.9 15.7 4.|-- m-ef2-i.M.DE.NET.DTAG.DE 0.0% 10 8.1 8.1 7.7 9.2 0.4 5.|-- 80.150.168.185 0.0% 10 13.5 14.5 12.4 23.9 3.4 6.|-- cloudflare-gw.cr0-muc1.ip 70.0% 10 7.8 8.4 7.3 10.1 1.5 7.|-- 104.26.14.172 0.0% 10 7.0 7.5 7.0 8.5 0.4 ``` This slowdown has been occurring since January 2024, according to other Cloudflare users: ![ICMP history](https://gerfficient.com/user/pages/home/telekom-and-cloudflare/icmp-history.png)*Quelle: Cloudflare Community (falke1337)[3](#fn:3)* And now that I've switched to a different Internet provider, the connection is much more stable and faster: ```bash $ traceroute zangs.com traceroute: Warning: zangs.com has multiple addresses; using 104.21.48.1 traceroute to zangs.com (104.21.48.1), 64 hops max, 40 byte packets 1 192.168.1.1 (192.168.1.1) 2.136 ms 1.962 ms 1.437 ms 2 10.19.6.67 (10.19.6.67) 13.850 ms 10.19.6.66 (10.19.6.66) 9.935 ms 10.19.6.67 (10.19.6.67) 8.631 ms 3 xe-0-1-13.core-mbb.komro.net (37.156.85.228) 8.196 ms 37.156.85.230 (37.156.85.230) 10.971 ms xe-0-1-13.core-mbb.komro.net (37.156.85.228) 9.619 ms 4 ae1.core-ow.komro.net (37.156.85.180) 13.086 ms et-0-0-1.pe-muc-equinix01.komro.net (37.156.85.189) 15.052 ms ae1.core-ow.komro.net (37.156.85.180) 10.618 ms 5 de-cix-munich.as13335.net (185.1.208.9) 13.629 ms et-0-0-1.pe-muc-equinix01.komro.net (37.156.85.189) 10.753 ms de-cix-munich.as13335.net (185.1.208.9) 12.972 ms 6 de-cix-munich.as13335.net (185.1.208.9) 11.868 ms 104.21.48.1 (104.21.48.1) 17.115 ms de-cix-munich.as13335.net (185.1.208.9) 13.027 ms ``` --- 1. [Bad latencies and download rates due to missing peering with Deutsche Telekom AG](https://community.cloudflare.com/t/bad-latencies-and-download-rates-due-to-missing-peering-with-deutsche-telekom-ag/681147) [↩](#fnref1:1) 2. [Connection to CF via German Telekom is very slow](https://community.cloudflare.com/t/connection-to-cf-via-german-telekom-is-very-slow/656849) [↩](#fnref1:2) 3. [Latency to proxied DNS entries high since 2024-01-30T07:09:15CET](https://community.cloudflare.com/t/latency-to-proxied-dns-entries-high-since-2024-01-30t0715cet/608356) [↩](#fnref1:3) --- ## Navigation - Parent: [Home](https://gerfficient.com/en/index.md) - Previous: [Der Einstieg in ComfyUI](https://gerfficient.com/en/home/comfyui-101.md) - Next: [Webpage in the Homelab](https://gerfficient.com/en/home/homelab-webpage.md)