{"product_id":"76-lessons-from-running-an-isp","title":"76 Lessons from Running an ISP","description":"\u003cp\u003eEvery expensive mistake made building and running a fibre ISP, written down so you don't have to repeat them.\u003c\/p\u003e\n\u003ch3\u003eA sample of what's inside\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eWhy two tunnels to one destination through CGNAT costs you 40–60% packet loss — and why nothing in your config will tell you\u003c\/li\u003e\n\u003cli\u003eWhy a routing change per customer needs a scoped connection-tracking flush, or the customer stays on both paths for 24 hours\u003c\/li\u003e\n\u003cli\u003eWhy \u003ccode\u003e\/ppp active\u003c\/code\u003e filters look like they work and silently don't — with the two-line proof\u003c\/li\u003e\n\u003cli\u003eWhy a blackholed DNS pin looks exactly like a slow VPN\u003c\/li\u003e\n\u003cli\u003eWhy the far end's autonegotiation advertisement is what limits your link speed, and why forcing the speed kills it entirely\u003c\/li\u003e\n\u003cli\u003eWhy a brand-new patch cable can still be your fault\u003c\/li\u003e\n\u003cli\u003eWhy \"connection refused\" and \"connection timed out\" send you to completely different problems\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eWho this is for\u003c\/h3\u003e\n\u003cp\u003eEngineers running or building a small ISP on MikroTik and RADIUS. Every lesson came from a real outage, a real wasted afternoon, or a real invoice. Several cost weeks.\u003c\/p\u003e\n\u003ch3\u003eWhat it isn't\u003c\/h3\u003e\n\u003cp\u003eNot a beginner's tutorial and not vendor documentation. It assumes you know what PPPoE and a routing table are, and goes straight to the failures that documentation never mentions.\u003c\/p\u003e\n\u003cp\u003eInstant download, PDF. Free updates as the list grows.\u003c\/p\u003e","brand":"Culmen","offers":[{"title":"PDF download","offer_id":54337998258519,"sku":"CLM-DL-76LESSONS","price":29.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1038\/2937\/3271\/files\/76-lessons-from-running-an-isp_c2d13c3a-8d80-4de8-8744-8127c5c36080.png?v=1786770577","url":"https:\/\/culmensoft.com\/products\/76-lessons-from-running-an-isp","provider":"Culmen","version":"1.0","type":"link"}