Initial commit of Sphinx docs

Change-Id: I9fca8fb98502dffc2555f9de7f507b6f006e0e77
Signed-off-by: John DeNisco <jdenisco@cisco.com>

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+.. _Routing:
+
+.. toctree::
+
+Connecting the two Containers
+_____________________________
+
+Now for connecting these two linux containers to VPP and pinging between them.
+
+Enter container *cone*, and check the current network configuration:
+
+.. code-block:: console
+    
+    root@cone:/# ip -o a
+    1: lo    inet 127.0.0.1/8 scope host lo\       valid_lft forever preferred_lft forever
+    1: lo    inet6 ::1/128 scope host \       valid_lft forever preferred_lft forever
+    30: veth0    inet 10.0.3.157/24 brd 10.0.3.255 scope global veth0\       valid_lft forever preferred_lft forever
+    30: veth0    inet6 fe80::216:3eff:fee2:d0ba/64 scope link \       valid_lft forever preferred_lft forever
+    32: veth_link1    inet6 fe80::2c9d:83ff:fe33:37e/64 scope link \       valid_lft forever preferred_lft forever
+
+You can see that there are three network interfaces, *lo, veth0*, and *veth_link1*.
+
+Notice that *veth_link1* has no assigned IP.
+
+Check if the interfaces are down or up:
+
+.. code-block:: console
+
+    root@cone:/# ip link
+    1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1
+        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
+    30: veth0@if31: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
+        link/ether 00:16:3e:e2:d0:ba brd ff:ff:ff:ff:ff:ff link-netnsid 0
+    32: veth_link1@if33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
+        link/ether 2e:9d:83:33:03:7e brd ff:ff:ff:ff:ff:ff link-netnsid 0
+
+.. _networkNote:
+
+.. note::
+
+    Take note of the network index for **veth_link1**. In our case, it 32, and its parent index (the host machine, not the containers) is 33, shown by **veth_link1@if33**. Yours will most likely be different, but **please take note of these index's**.
+
+Make sure your loopback interface is up, and assign an IP and gateway to veth_link1.
+
+.. code-block:: console
+    
+    root@cone:/# ip link set dev lo up
+    root@cone:/# ip addr add 172.16.1.2/24 dev veth_link1
+    root@cone:/# ip link set dev veth_link1 up
+    root@cone:/# dhclient -r
+    root@cone:/# ip route add default via 172.16.1.1 dev veth_link1
+
+Here, the IP is 172.16.1.2/24 and the gateway is 172.16.1.1.
+
+Run some commands to verify the changes:
+
+.. code-block:: console
+    
+    root@cone:/# ip -o a
+    1: lo    inet 127.0.0.1/8 scope host lo\       valid_lft forever preferred_lft forever
+    1: lo    inet6 ::1/128 scope host \       valid_lft forever preferred_lft forever
+    30: veth0    inet6 fe80::216:3eff:fee2:d0ba/64 scope link \       valid_lft forever preferred_lft forever
+    32: veth_link1    inet 172.16.1.2/24 scope global veth_link1\       valid_lft forever preferred_lft forever
+    32: veth_link1    inet6 fe80::2c9d:83ff:fe33:37e/64 scope link \       valid_lft forever preferred_lft forever
+
+    root@cone:/# route
+    Kernel IP routing table
+    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
+    default         172.16.1.1      0.0.0.0         UG    0      0        0 veth_link1
+    172.16.1.0      *               255.255.255.0   U     0      0        0 veth_link1
+
+
+We see that the IP has been assigned, as well as our default gateway.
+
+Now exit this container and repeat this process with container *ctwo*, except with IP 172.16.2.2/24 and gateway 172.16.2.1.
+
+
+After thats done for *both* containers, exit from the container if you're in one:
+
+.. code-block:: console
+    
+    root@ctwo:/# exit
+    exit
+    root@localhost:~#
+
+In the machine running the containers, run **ip link** to see the host *veth* network interfaces, and their link with their respective *container veth's*.
+
+.. code-block:: console
+    
+    root@localhost:~# ip link
+    1: lo: <LOOPBACK> mtu 65536 qdisc noqueue state DOWN mode DEFAULT group default qlen 1
+        link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
+    2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+        link/ether 08:00:27:33:82:8a brd ff:ff:ff:ff:ff:ff
+    3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+        link/ether 08:00:27:d9:9f:ac brd ff:ff:ff:ff:ff:ff
+    4: enp0s9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+        link/ether 08:00:27:78:84:9d brd ff:ff:ff:ff:ff:ff
+    5: lxcbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
+        link/ether 00:16:3e:00:00:00 brd ff:ff:ff:ff:ff:ff
+    19: veth0C2FL7@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master lxcbr0 state UP mode DEFAULT group default qlen 1000
+        link/ether fe:0d:da:90:c1:65 brd ff:ff:ff:ff:ff:ff link-netnsid 1
+    21: veth8NA72P@if20: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
+        link/ether fe:1c:9e:01:9f:82 brd ff:ff:ff:ff:ff:ff link-netnsid 1
+    31: vethXQMY4C@if30: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master lxcbr0 state UP mode DEFAULT group default qlen 1000
+        link/ether fe:9a:d9:29:40:bb brd ff:ff:ff:ff:ff:ff link-netnsid 0
+    33: vethQL7KOC@if32: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000
+        link/ether fe:ed:89:54:47:a2 brd ff:ff:ff:ff:ff:ff link-netnsid 0
+
+
+Remember our network interface index 32 in *cone* from this :ref:`note <networkNote>`? We can see at the bottom the name of the 33rd index **vethQL7KOC@if32**. Keep note of this network interface name for the veth connected to *cone* (ex. vethQL7KOC), and the other network interface name for *ctwo*.
+
+With VPP in the host machine, show current VPP interfaces:
+
+.. code-block:: console
+    
+    root@localhost:~# vppctl show inter
+              Name               Idx    State  MTU (L3/IP4/IP6/MPLS)     Counter          Count     
+    local0                        0     down          0/0/0/0  
+
+Which should only output local0.
+
+Based on the names of the network interfaces discussed previously, which are specific to my systems, we can create VPP host-interfaces:
+
+.. code-block:: console
+    
+    root@localhost:~# vppctl create host-interface name vethQL7K0C
+    root@localhost:~# vppctl create host-interface name veth8NA72P
+
+Verify they have been set up properly:
+
+.. code-block:: console
+    
+    root@localhost:~# vppctl show inter
+              Name               Idx    State  MTU (L3/IP4/IP6/MPLS)     Counter          Count     
+    host-vethQL7K0C               1     down         9000/0/0/0     
+    host-veth8NA72P               2     down         9000/0/0/0     
+    local0                        0     down          0/0/0/0   
+
+Which should output *three network interfaces*, local0, and the other two host network interfaces linked to the container veth's.
+
+
+Set their state to up:
+
+.. code-block:: console
+    
+    root@localhost:~# vppctl set interface state host-vethQL7K0C up
+    root@localhost:~# vppctl set interface state host-veth8NA72P up
+
+Verify they are now up:
+
+.. code-block:: console
+
+    root@localhost:~# vppctl show inter
+              Name               Idx    State  MTU (L3/IP4/IP6/MPLS)     Counter          Count     
+    host-vethQL7K0C               1      up          9000/0/0/0     
+    host-veth8NA72P               2      up          9000/0/0/0     
+    local0                        0     down          0/0/0/0   
+
+
+Add IP addresses for the other end of each veth link:
+
+.. code-block:: console
+    
+    root@localhost:~# vppctl set interface ip address host-vethQL7K0C 172.16.1.1/24
+    root@localhost:~# vppctl set interface ip address host-veth8NA72P 172.16.2.1/24
+
+
+Verify the addresses are set properly by looking at the L3 table:
+
+.. code-block:: console
+
+    root@localhost:~# vppctl show inter addr
+    host-vethQL7K0C (up):
+      L3 172.16.1.1/24
+    host-veth8NA72P (up):
+      L3 172.16.2.1/24
+    local0 (dn):
+
+Or looking at the FIB by doing:
+
+.. code-block:: console
+    
+    root@localhost:~# vppctl show ip fib
+    ipv4-VRF:0, fib_index:0, flow hash:[src dst sport dport proto ] locks:[src:plugin-hi:2, src:default-route:1, ]
+    0.0.0.0/0
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:1 buckets:1 uRPF:0 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    0.0.0.0/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:2 buckets:1 uRPF:1 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    172.16.1.0/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:10 buckets:1 uRPF:9 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    172.16.1.0/24
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:9 buckets:1 uRPF:8 to:[0:0]]
+        [0] [@4]: ipv4-glean: host-vethQL7K0C: mtu:9000 ffffffffffff02fec953f98c0806
+    172.16.1.1/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:12 buckets:1 uRPF:13 to:[0:0]]
+        [0] [@2]: dpo-receive: 172.16.1.1 on host-vethQL7K0C
+    172.16.1.255/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:11 buckets:1 uRPF:11 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    172.16.2.0/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:14 buckets:1 uRPF:15 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    172.16.2.0/24
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:13 buckets:1 uRPF:14 to:[0:0]]
+        [0] [@4]: ipv4-glean: host-veth8NA72P: mtu:9000 ffffffffffff02fe305400e80806
+    172.16.2.1/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:16 buckets:1 uRPF:19 to:[0:0]]
+        [0] [@2]: dpo-receive: 172.16.2.1 on host-veth8NA72P
+    172.16.2.255/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:15 buckets:1 uRPF:17 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    224.0.0.0/4
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:4 buckets:1 uRPF:3 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    240.0.0.0/4
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:3 buckets:1 uRPF:2 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+    255.255.255.255/32
+      unicast-ip4-chain
+      [@0]: dpo-load-balance: [proto:ip4 index:5 buckets:1 uRPF:4 to:[0:0]]
+        [0] [@0]: dpo-drop ip4
+
+At long last you probably want to see some pings:
+
+.. code-block:: console
+    
+    root@localhost:~# lxc-attach -n cone -- ping -c3 172.16.2.2
+    PING 172.16.2.2 (172.16.2.2) 56(84) bytes of data.
+    64 bytes from 172.16.2.2: icmp_seq=1 ttl=63 time=0.102 ms
+    64 bytes from 172.16.2.2: icmp_seq=2 ttl=63 time=0.189 ms
+    64 bytes from 172.16.2.2: icmp_seq=3 ttl=63 time=0.150 ms
+
+    --- 172.16.2.2 ping statistics ---
+    3 packets transmitted, 3 received, 0% packet loss, time 1999ms
+    rtt min/avg/max/mdev = 0.102/0.147/0.189/0.035 ms
+
+    root@localhost:~# lxc-attach -n ctwo -- ping -c3 172.16.1.2
+    PING 172.16.1.2 (172.16.1.2) 56(84) bytes of data.
+    64 bytes from 172.16.1.2: icmp_seq=1 ttl=63 time=0.111 ms
+    64 bytes from 172.16.1.2: icmp_seq=2 ttl=63 time=0.089 ms
+    64 bytes from 172.16.1.2: icmp_seq=3 ttl=63 time=0.096 ms
+
+    --- 172.16.1.2 ping statistics ---
+    3 packets transmitted, 3 received, 0% packet loss, time 1998ms
+    rtt min/avg/max/mdev = 0.089/0.098/0.111/0.014 ms
+
+
+Which should send/recieve three packets for each command.
+
+This is the end of this guide. Great work! 
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