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+# Yaml Format
+
+## Node Definition
+
+### Node type
+
+- name: node name. It will be container-name or netns-name.
+- type: node type (default: docker)
+	- docker: node is docker container
+	- netns: node is just network namespace
+- image: specify docker-image
+- sysctls: set sysctls 
+- mounts: mounts file/directory on the container
+
+```
+nodes:
+  - name: Node0
+    image: ubuntu:18.04
+  - name: Node1
+    type: netns
+	- name: Node2
+	  build: .
+```
+
+### Interface Definition
+
+- type
+	- direct: p2p connect to other container
+	- bridge: bridge connection
+	- phys  : host's network interface
+- mac: specify mac address
+
+```
+nodes:
+  - name: Node0
+    image: ubuntu:18.04
+    interfaces:
+      - { name: net0, type: direct, args: R0#net1 }
+      - { name: net0, type: bridge, args: B0 }
+      - { name: eth0, type: phys }
+      - { name: net0, type: direct, args: R1#net1, mac: 11:11:11:11:11:11 }
+```
+
+### Bridge Definition
+
+If you use the bridge interface type, you need to
+define the Bridge-Instance. It'll be created as a
+linux bridge instance.
+
+- name: interface name
+- type: interface type, you must choose following.
+	- docker: net-if of docker container
+	- netns: net-if of network namespace
+	- phys: host's network interface
+
+```
+bridges:
+  - name: Bridge0
+    interfaces:
+      - { name: net0, type: docker, args: R0 }
+      - { name: net0, type: netns, args: NS0 }
+      - { name: eth0, type: phys }
+```
+
+## Config Definition
+- name: node name
+- cmds: shell command
+
+```
+node_configs:
+  - name: Router1
+    cmds:
+      - cmd: ip addr add 10.255.0.10/32 dev lo
+      - cmd: ip addr add 10.0.0.10/24 dev net0
+			- copy: ./config.conf /usr/local/config.conf
+  - name: Router0
+    cmds:
+      - cmd: sysctl -w 'net.ipv4.fib_multipath_hash_policy=1'
+      - cmd: /usr/lib/frr/frr start
+      - cmd: ip addr add 10.255.0.1/32 dev lo
+      - cmd: ip addr add 10.0.0.1/24 dev net0
+      - cmd: ip addr add 10.1.0.1/24 dev net1
+      - cmd: >-
+          vtysh -c 'conf t'
+          -c 'router bgp 100'
+          -c ' bgp router-id 10.255.0.1'
+          -c ' neighbor 10.0.0.10 remote-as 100'
+          -c ' neighbor 10.0.0.20 remote-as 100'
+          -c ' neighbor 10.0.0.30 remote-as 100'
+```
+
+## Test Definition
+
+- name: test name, you can specify when you run `tn conf -n <name>`
+- cmds: same format of config definition
+
+```
+test:
+  - name: p2p
+	  cmds:
+    - cmd: docker exec S0 ping -c2 10.1.0.1
+    - cmd: docker exec S1 ping -c2 192.168.0.1
+    - cmd: docker exec S2 ping -c2 192.168.0.1
+    - cmd: docker exec S3 ping -c2 192.168.0.1
+  - name: remote
+	  cmds:
+    - cmd: docker exec S0 ping -c2 10.1.0.1
+    - cmd: docker exec S1 ping -c2 192.168.0.1
+    - cmd: docker exec S2 ping -c2 192.168.0.1
+    - cmd: docker exec S3 ping -c2 192.168.0.1
+```
+
+## System Requirement Definition
+
+```
+require:
+	- kernel_min: 4.11.0
+	- kernel_max: 4.15.0
+	- kmod: [ mpls_router, mpls_iptunnel, mpls_gso ]
+  - kconfig: [ CONFIG_NET_L3_MASTER_DEV ]
+```