cisco

NANOG 75 in San Francisco

Anurag Bhatia
Attending NANOG 75 in San Francisco. I have always found NANOG very fascinating w.r.t the size of event and a fact that internet started in this side of world. Yesterday was day 0 with Hackathon and task was network automation with ZTP, Ansible, Open/R for IGP etc. 😄 Our team’s presentation about it:

Encrypted DNS using DNSCrypt

Anurag Bhatia
Writing this post from my hotel room in Kathmandu. I found that many of the servers appear to be DNS resolvers which is unusual. Have a look at these weird DNS replies: dig @anuragbhatia.com . ns +short a.root-servers.net. b.root-servers.net. c.root-servers.net. d.root-servers.net. e.root-servers.net. f.root-servers.net. g.root-servers.net. h.root-servers.net. i.root-servers.net. j.root-servers.net. k.root-servers.net. l.root-servers.net. m.root-servers.net. dig @google.com . ns +short b.root-servers.net. c.root-servers.net. d.root-servers.net. e.root-servers.net. f.root-servers.net. g.root-servers.net. h.root-servers.net. i.root-servers.net. j.root-servers.net. k.root-servers.net. l.root-servers.net. m.root-servers.net. a.root-servers.net. This seems unusual and is the result of basically port 53 DNS hijack.

BGP Administrative Shutdown Communication

Anurag Bhatia
I recently came across an excellent draft at IETF by Job Snijders & friends. This is to address scenarios where a network might miss communication about a maintenance activity when BGP shutdown happens. Once implemented, this can potentially offer to send peer a message with up to 128 bytes with info about shutdown like “Ticket XXX: We are upgrading the router, will be back live in 1hr” etc. It depends by appending such data to the sys notification which is part of BGP protocol.

Route filter generation for Mikrotik RouterOS via IRR

Anurag Bhatia
A while back I posted about routing filter generation via bgpq3 for Cisco (ios and XR) and Juniper JunOS based routers. I have received a number of emails in last few months about automated filter generation for Mikrotik routeros. Since Mikrotik’s CCRs are getting quite popular across small to mid-sized ISPs. So this blog post is about ways for generating filter config for a given ASN via IRR. One can use such logic with some kind of remote login mechanism like rancid (look for mtlogin here).