A blog post dedicated to BSNL AS9829. It just tried so hard to become as irrelevant as it can from everyone’s life (and that doesn’t excludes me now). So what really is BSNL btw?
A Govt of India telco sitting at a extensive fiber of over 600,000 Kms across the country (staying just unused and unavailable for anyone’s use!) A telco which has an extensive last mile copper (which is very poorly maintained and barely works!
One of things which people often asked me around in past was on how to have multiple IPs on Linux machine under various circumstances. I know there are ton of blog posts about this but very few explain how it works and possible options under different use cases etc. I will share router side and server side config with focus on how it should be done from server end. Assuming server side config to be for Ubuntu/Debian.
One of very cool features of IPv6 is link-local address which stays local to a given link. For this fe80::/10 is reserved. A /10 is a huge amount of address space in IPv6 (and in IPv4 too :) ). This means from fe80:0000:0000:0000:0000:0000:0000:0000 to febf:ffff:ffff:ffff:ffff:ffff:ffff:ffff.
Since by design link-local address stays local, the address configured on the upstream/gateway router can be kept same for ease of use and comfort. This wasn’t the case of IPv4 where each VLAN/layer 2 domain had it’s own gateway.
Out in Mumbai to attend SANOG 26.
Meet and greet if you are attending as well or around in Mumbai. :)
Came across this excellent presentation of Peter Hoose (Facebook). It gives a very good logical way of troubleshooting problems. Less about actual problems but about how Ops members companies like Facebook troubleshoot them.
This is from NANOG 64. Enjoy the presentation. :)