Isp-Column

BCP38 - also known as “Network Ingress Filtering” is concept where we filter incoming packets from end customers and allow packets ONLY from IP’s assigned to them.   Before going to BCP38, let’s first understand how packets forwarding work:

Here User 1 is connected to User 2 via a series of router R1, R2 and R3. Here R1 and R3 are ISP’s edge routers while R2 is a core router. In typical way the network is setup, entire effort is given on logic of routing table i.e for packets to reach from User 1 to User 2, we need to ensure that User 1 has default route towards R1, knows that User-2’s IP is behind R3 which is reachable via R2. So path User 1 > R1 > R2 > R3 > User 2 comes up. And same for User 2 > R3 > R2 > R1 > User 1 as return path. Now e.g IP pool for User-1 is 192.168.1.0/24 and is using 192.168.1.2 out of it while IP pool for User-2 is 192.168.2.0/24 and is using 192.168.2.2 out of it.  

Just finished with SANOG 26 conference and tutorials. It went very nice. Interestingly this time conference did not start early morning like it did in SANOG 24 at Noida. It was rather late in afternoon. Also, on very good note - there were less Govt. bureaucrats to bore attendees with usual stuff they always talk about but have very little idea. One specific interesting presentation was  Opportunities and Challenges for Broadband Wireless in India by Prof Abhay Karandikar (from IIT Mumbai). In start I felt it to be usual crappy 5G talk but later realized it was much more interesting. I loved the idea “Have 2Mbps everywhere static broadband and not some absurd number on mobile wireless broadband as we hear in case of 3G/4G. Although 2Mbps now is much slower and I would rather suggest that we target for 10Mbps everywhere (something which can be supported by copper/coax/fiber hybrid) but anyways it was nice refreshing talk. His thoughts were interesting but mostly impractical since had high dependence on useless project like NOFN. For the next part, we had a nice theme of keeping network simple which everyone kind of liked. Simplicity in Network Design & Deployments by Dany Pinto (from Colt) and Unified Forwarding with Segment Routing by Mohan Nanduri (from Microsoft Azure Cloud WAN team) were part of that. Santanu Dasgupta gave a presentation about Challenges of L2NID based Metro-E Architecture for vCPE/NFV Deployments and kind of confused everyone. :P