First of all. I should apologize for this thread - seems it is one more grinding of the well-known things. And I never opposed to you. Second, it seems for me there is really a lack of the good books about the INTERNET and it's routing. The book mentioned below (btw, the author's name at the paper book is Bassam Halabi, and differ slightly from the one at the CCO server) describe BGP brightly, but do not explain HOW TO DESIGN SIMPLE single-homed customer's network; multi-homed customer's network; non-transit ISP; transit ISP... And then (It's more the request to those who write the books) there is a lack of the books explaining _what for this protocol was designed_ and _how to use it in the 90% cases_. Good example #1 - OSPF - all books describe AREAS, STUB's, DEAD INTERVAL, etc etc - but the first idea of OSPF was _to be very simple in the simple cases_. It causes the students (I had a time to watch their attempts to do simple labs here) to write a complex, 100 lines-at-the-size configs from the first minute they began to type in something into the router, or write terrible _redistribute_, _stub_ etc when this configs are not necessary at all. This resulted to the myths about the _complexity_ or _unstability_ or _difficulty to config_ etc etc... BGP - the same problem. Halabi write the excellent book; but try to configure the simple _multi-homed_ customer's network guided by this tool? First of all, no one word about IGP backgrounding network; second, no distinction between the _SIMPLE_ cases (when it's better to write router bgp 1111 network 193.124.0.0 255.254.0.0 neig 1.2.3.4 remote-as 1112 ... ip route 193.124.0.0 255.254.0.0 Null0 254 and the complex cases when you should transit third-party BGP routes by your multi-area backbones. And it's amazing - we are talking (this days) about L2/L3 switching, about MPLS, tagging etc etc - and we just have almost ready 2-level network (IGP - IBGP), but withouth any attempting to use any packet tagging. Think - edge router receive the packet, and find the appropriate route in BGP table; this route reference to the BGP next hop (outgoing edge router). Instead of the tagging this packet by this _NEXT HOP_ address (and marking it's CoQ and other attributes) it send it unchanged to the next core router and the whole indentification repeats again... and again... And then some folks cry _we can use ATM background instead of IGP background_ and draw MPLS heap of comlexity... Btw, if summ everything was saying here in nanog by this Sublect, we could collect a good FAQ by this subject _how to build simple ISP backbone_ -:). Aleksei Roudnev, Network Operations Center, Relcom, Moscow (+7 095) 194-19-95 (Network Operations Center Hot Line),(+7 095) 230-41-41, N 13729 (pager) (+7 095) 196-72-12 (Support), (+7 095) 194-33-28 (Fax)