NDN NAC Chengyu Fan 1

Motivation Currently, NDN users need manual configuration before they can publish or consume content NDN Auto-configuration (NAC) eliminates need for manual configurations Ex: As soon as you open your laptop in retreat meeting, it connects your laptop to NDN automatically 2

Challenges Where is the NDN gateway? Need to send Interest packets Could be multiple gateways Different namespaces reachable via different gateways Which namespace that the user can use to publish content? Receive Interest to publish data Even chat, web browser, et al. need to publish data Which key is associated with this namespace? Allow others to verify your data May need to associate key with namespace Signed data and keys may expire 3

Approach Evolutionary approach, not revolutionary approach Build on existing auto-configuration systems DHCP is the main auto-configuration system today Utilizing DHCP mechanism to provide NDN configuration parameters Deployment goals and assumptions Eventually, we would like to see that all DHCP servers support NDN In a long period, some DHCP servers do not support NDN May not be an NDN capable server in local subnet Modify DHCP clients and servers to meet these goals 4

DHCP Review 5 Collect OFFERs, choose one commit configuration

How to include NDN in DHCP? DHCP options: Options are in all DHCP messages Configuration parameters are stored in the 'options' field Format DHCP client can use options to request NDN parameters Code = 55: Parameter Request List Used by a DHCP client to request specified configuration parameters Value includes the NDN code numbers DHCP server responds with NDN options, if supported Code = : reserved for private use Code = 246: NDN NAC server address Code = 247: NDN gateway address, port, reachable namespace Code = 248: NDN namespace for client use 6

How to include NDN in DHCP? (cont.) 7 Collect OFFERs, choose one commit configuration

Incremental deployment problem 1. Some DHCP Servers on local subnet support NDN, some don’t 2. DHCP Servers on local subnet don’t support NDN, but can install NDN capable server(s) If new server can also hand out IP, back to case 1 Suppose new server can’t hand out addresses…. 3. No DHCP servers and not ability to install NDN capable server on local subnet 8

Some DHCP Servers on local subnet support NDN, some don’t … 9 Choose NDN parameters and IP Commit Configuration Summary: 1.No changes on the regular DHCP server 2.We have to modify the DHCP client code Request NDN parameters choose the OFFER with NDN parameters 3.We have to modify the DHCP server to support NDN Listen for NDN parameters Allocate namespace for clients Send NDN parameters in response

NDN servers cannot assign IP address… 10 Summary: 1.No changes on the DHCP server infrastructure 2.Modified DHCP client can only get IP, but no NDN parameters 3.Need a way to find the NDN servers NDN servers cannot reply because they don’t have IP addresses to assign

How to find NDN servers? Existing DHCP servers can report NDN server Require no changes to the existing DHCP server code DHCP server configuration allows one to report options But this still requires configuration change on the DHCP server Client broadcasts DHCPINFORM to find NDN servers Requires no changes to the existing DHCP server code and configuration Servers MUST NOT change lease upon receiving DHCPINFORM and will ignore the DHCPINFORM NDN servers will reply to the DHCPINFORM with DHCPACK But NDN servers may not be in the local subnet Client queries DNS for address of NDN server Unicast DHCPINFORM to the NDN server 11

Summary of the NAC design 12

How to get the NAC server? 13 Admin configures regular DHCP server to provide NAC server’s address Broadcast 247 and 248 result in multiple replies, the server has no idea if he is chosen

Thank you! 14