| Router Configuration |
| ==================== |
| |
| .. toctree:: |
| .. |
| |
| Example network and sample configuration |
| ---------------------------------------- |
| |
| Assume that three routers in the same network, but at three different sites |
| (``memphis.edu``, ``arizona.edu``, and ``colostate.edu``), are connected to each other to |
| construct the following topology: |
| |
| :: |
| |
| +-------------------------------------+ |
| | /ndn/edu/memphis/%C1.Router/router1 | |
| +-------------------------------------+ |
| / 11 12\ |
| / \ |
| route-cost = 25 / \ route-cost = 30 |
| / \ |
| 17 / \ 13 |
| +-----------------------------------+ 7 10 +-------------------------------------+ |
| |/ndn/edu/arizona/%C1.Router/router3|-------------------|/ndn/edu/colostate/%C1.Router/router2| |
| +-----------------------------------+ route-cost = 28 +-------------------------------------+ |
| |
| Figure: Network Topology |
| |
| The number represents the connecting face id. For example, |
| ``/ndn/edu/memphis/%C1.Router/router1`` is connected to |
| ``/ndn/edu/arizona/%C1.Router/router3`` via face 11 and the route cost is 25. To reach |
| ``/ndn/edu/colostate/%C1.Router/router2`` via face 12, the route cost is 30. |
| |
| We will walk through setting up the faces and creating the configuration file for |
| ``/ndn/edu/memphis/%C1.Router/router1``. |
| |
| It is recommended to configure security as described at :doc:`SECURITY-CONFIG`, before |
| starting router configuration. |
| |
| Step 1. Ensuring nfd is running |
| ------------------------------- |
| |
| Type the following in the terminal: |
| |
| :: |
| |
| nfd-status |
| |
| If you see ``error while connecting to the forwarder (No such file or directory)``, |
| ``nfd`` is not running. Follow the instructions in `Getting started with NFD |
| <http://named-data.net/doc/NFD/current/INSTALL.html>`_ to run nfd. |
| |
| Since v0.4.0, NLSR no longer creates Faces for the neighbors that are |
| specified in ``nlsr.conf``. Instead, it relies on the pre-existence of |
| the Faces in NFD. NLSR will obtain this information from NFD, and |
| configure its neighbors using this information. |
| |
| To create faces it is now necessary to use the ``nfdc`` command. Its documentation can |
| be found `here |
| <https://named-data.net/doc/NFD/current/manpages/nfdc.html>`_ |
| |
| Step 2. Determining FaceUri |
| --------------------------- |
| |
| Assume that ``/ndn/edu/arizona/%C1.Router/router3`` has hostname ``router3.arizona.edu`` and |
| ``/ndn/edu/colostate/%C1.Router/router2`` has IP address ``79.123.10.145``. |
| ``/ndn/edu/memphis/%C1.Router/router1`` will consider FaceUri |
| ``udp4://router3.arizona.edu`` for router ``/ndn/edu/arizona/%C1.Router/router3`` and |
| FaceUri ``udp4://79.123.10.145`` for router ``/ndn/edu/colostate/%C1.Router/router2``. |
| |
| Step 3: Creating configuration file |
| ----------------------------------- |
| |
| Now, assume that ``/ndn/memphis.edu/router1`` wants to advertise three name prefixes |
| (``/ndn/memphis/sports/basketball/grizzlies``, ``/ndn/memphis/entertainment/blues``, |
| ``/ndn/news/memphis/politics/lutherking``). The configuration file with the necessary |
| configuration commands follows: |
| |
| :: |
| |
| ; nlsr.conf starts here |
| ; the general section contains all the general settings for router |
| |
| general |
| { |
| ; mandatory configuration command section network, site and router |
| network /ndn/ ; name of the network the router belongs to in ndn URI format |
| site /edu/memphis/ ; name of the site the router belongs to in ndn URI format |
| router /%C1.Router/router1 ; name of the network the router belongs to in ndn URI format |
| |
| ; lsa-refresh-time is the time in seconds, after which router will refresh its LSAs |
| lsa-refresh-time 1800 ; default value 1800. Valid values 240-7200 |
| |
| ; InterestLifetime (in seconds) for LSA fetching |
| lsa-interest-lifetime 4 ; default value 4. Valid values 1-60 |
| |
| state-dir /var/lib/nlsr/ ; state directory to store all dynamic changes to NLSR |
| } |
| |
| ; the neighbors section contains the configuration for router's neighbors and hello's behavior |
| |
| neighbors |
| { |
| ; in case hello interest timed out, router will try 'hello-retries' times at 'hello-time-out' |
| ; seconds interval before giving up for any neighbors (deciding link is down) |
| |
| hello-retries 3 ; interest retries number in integer. Default value 3 |
| ; valid values 1-10 |
| |
| hello-timeout 1 ; interest time out value in integer. Default value 1 |
| ; Valid values 1-15 |
| |
| hello-interval 60 ; interest sending interval in seconds. Default value 60 |
| ; valid values 30-90 |
| |
| ; adj-lsa-build-interval is the time to wait in seconds after an Adjacency LSA |
| ; build is scheduled before actually building the Adjacency LSA |
| |
| adj-lsa-build-interval 5 ; default value 5. Valid values 0-5. It is recommended that |
| ; adj-lsa-build-interval have a lower value than |
| ; routing-calc-interval |
| |
| ; first-hello-interval is the time to wait in seconds before sending the first Hello Interest |
| |
| first-hello-interval 10 ; Default value 10. Valid values 0-10 |
| |
| ; neighbor command is used to configure router's neighbor. Each neighbor will need |
| ; one block of neighbor command |
| |
| neighbor |
| { |
| name /ndn/edu/arizona/%C1.Router/router3 ; name prefix of the neighbor router consists |
| ; of network, site-name and router-name |
| |
| face-uri udp4://router3.arizona.edu ; face uri of the face connected to the neighbor |
| link-cost 25 ; cost of the connecting link to neighbor |
| } |
| |
| neighbor |
| { |
| name /ndn/edu/colostate/%C1.Router/router2 ; name prefix of the neighbor router consists |
| ; of network, site-name and router-name |
| |
| face-uri udp4://79.123.10.145 ; face uri of the face connected to the neighbor |
| link-cost 30 ; cost of the connecting link to neighbor |
| } |
| } |
| |
| ; the hyperbolic section contains the configuration settings of enabling |
| a router to calculate ; routing table using `hyperbolic routing table |
| calculation`_ method |
| |
| hyperbolic |
| { |
| ; commands in this section follows a strict order |
| ; the switch is used to set hyperbolic routing calculation in NLSR |
| |
| state off ; default value 'off', set value 'on' to enable hyperbolic routing table |
| ; calculation which turns link state routing 'off'. set value to 'dry-run' |
| ; to test hyperbolic routing and compare with link state routing. |
| |
| |
| radius 123.456 ; radius of the router in hyperbolic coordinate system |
| angle 1.45 ; angle of the router in hyperbolic coordinate system |
| } |
| |
| |
| ; the fib section is used to configure fib entry's type to ndn FIB updated by NLSR |
| |
| fib |
| { |
| ; the max-faces-per-prefix is used to limit the number of faces for each name prefixes |
| ; by NLSR in ndn FIB |
| |
| max-faces-per-prefix 3 ; default value 0. Valid value 0-60. By default (value 0) NLSR adds |
| ; all available faces for each reachable name prefixes in NDN FIB |
| |
| } |
| |
| ; the advertising section contains the configuration settings of the |
| name prefixes ; hosted by this router |
| |
| advertising |
| { |
| ; the ndnname is used to advertised name from the router. To advertise each name prefix |
| ; configure one block of ndnname configuration command for every name prefix. |
| |
| prefix /ndn/memphis/sports/basketball/grizzlies |
| prefix /ndn/memphis/entertainment/blues |
| prefix /ndn/news/memphis/politics/lutherking |
| } |
| |
| By default NLSR's sequence file directory is set to ``/var/lib/nlsr/``. User must create this |
| directory before starting NLSR. Since this is a system directory, NLSR must either be executed |
| as root, or NLSR can be run as user "nlsr" after configuring the filesystem to grant "nlsr" |
| read and write permissions. If user lacks permissions, the following error will occur: |
| |
| :: |
| |
| User does not have read and write permission on the directory |
| Error in configuration file processing! Exiting from NLSR |
| |
| To avoid this, the directory can be set in a user-owned directory. For example: |
| |
| :: |
| |
| general |
| { |
| ... |
| |
| state-dir /home/username/nlsr/log ; path for sequence directory and other dynamic changes (Absolute path) |
| |
| } |
| ... |
| |
| The user will encounter errors such as the following if security is not configured: |
| |
| :: |
| |
| Cannot read certificate from file: /home/username/NLSR/root.cert |
| |
| To get rid of this and similar errors relating to security one has to configure security |
| as described in :doc:`SECURITY-CONFIG`. Security can be disabled for testing purposes as follows: |
| |
| :: |
| |
| ... |
| trust-anchor |
| { |
| type any |
| ;file-name "root.cert" |
| } |
| ... |
| trust-anchor |
| { |
| type any |
| ;file-name "site.cert" |
| } |
| ; cert-to-publish "root.cert" |
| ; cert-to-publish "router.cert" |
| ; cert-to-publish "site.cert" |
| ; cert-to-publish "router.cert" |
| |
| Or by simply replacing the whole security section with: |
| |
| :: |
| |
| security |
| { |
| validator |
| { |
| trust-anchor |
| { |
| type any |
| } |
| } |
| prefix-update-validator |
| { |
| trust-anchor |
| { |
| type any |
| } |
| } |
| } |
| |
| Step 4: Running NLSR on /ndn/memphis.edu/router1 |
| ------------------------------------------------- |
| |
| Assuming the configuration file is saved as ``nlsr.conf``, type the following to run nlsr: |
| |
| :: |
| |
| $ nlsr -f nlsr.conf |
| |
| NLSR will look for nlsr.conf in the current directory. If nlsr.conf is not in the current |
| directory, please provide the absolute path with the file name as the value. If |
| ``nlsr.conf`` resides in ``/home/ndnuser/configuration`` directory, type ``nlsr -f |
| /home/ndnuser/configuration/nlsr.conf`` to run nlsr. |
| |
| The same process needs to be followed for ``/ndn/arizona.edu/router3`` and |
| ``/ndn/colostate.edu/router2`` to run NLSR on these routers. |
| |
| Expected Output |
| ---------------- |
| |
| Assuming that all three routers are configured correctly and routing has converged, |
| ``nfd-status`` in ``/ndn/edu/colostate/%C1.Router/router2`` will have the following (or similar) |
| entries for the name advertised by ``/ndn/edu/memphis/%C1.Router/router1``: |
| |
| RIB: |
| |
| :: |
| |
| /ndn/memphis/entertainment/blues route={faceid=17 (origin=128 cost=25 ChildInherit), faceid=7 (origin=128 cost=58 ChildInherit)} |
| /ndn/memphis/sports/basketball/grizzlies route={faceid=17 (origin=128 cost=25 ChildInherit), faceid=7 (origin=128 cost=58 ChildInherit)} |
| /ndn/news/memphis/politics/lutherking route={faceid=17 (origin=128 cost=25 ChildInherit, faceid=7 (origin=128 cost=58 ChildInherit)} |
| |
| This output can be seen by typing ``nfdc route list`` in the terminal. Please refer to the |
| network figure for face IDs. |
| |
| .. _hyperbolic routing table calculation: http://arxiv.org/abs/0805.1266 |