# pica8 基本設定 ## 網路架構與 pica8 設定 在我們實驗架設的環境中，把 WiFi AP 連上 pica8 Switch 來提供對外網路連線，架構大致如下圖所示: ![](/files/-LPdbS-dlKU2g2Q7uXgO) 以下是 pica8 的網卡設定，可以看到有兩張網卡: eth0 和 eth1 分別對應對外網路 (用來 SSH 進入 pica8) 以及對內網路 (用來 SSH 其他 WiFi AP) ``` PICOS-OVS$ifconfig br0 Link encap:Ethernet HWaddr 08:9e:01:61:65:3f inet6 addr: fe80::a9e:1ff:fe61:653f/64 Scope:Link UP BROADCAST RUNNING PROMISC MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:4 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:500 RX bytes:0 (0.0 B) TX bytes:368 (368.0 B) eth0 Link encap:Ethernet HWaddr 08:9e:01:61:65:40 inet addr:140.113.xxx.xxx Bcast:140.113.xxx.255 Mask:255.255.255.0 inet6 addr: fe80::a9e:1ff:fe61:6540/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:16764 errors:0 dropped:0 overruns:0 frame:0 TX packets:663 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:1482645 (1.4 MiB) TX bytes:106647 (104.1 KiB) Base address:0xa000 eth1 Link encap:Ethernet HWaddr 08:9e:01:61:65:41 inet addr:192.168.1.2 Bcast:192.168.1.255 Mask:255.255.255.0 inet6 addr: fe80::a9e:1ff:fe61:6541/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:25 errors:0 dropped:0 overruns:0 frame:0 TX packets:58 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:2815 (2.7 KiB) TX bytes:4980 (4.8 KiB) Base address:0xe000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:26 errors:0 dropped:0 overruns:0 frame:0 TX packets:26 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:2728 (2.6 KiB) TX bytes:2728 (2.6 KiB) ``` ## pica8 flow table 設定 (bridge mode) 為了提供 WiFi AP 連網功能，我們要先設定好 pica8 上面 port 的對應關係，一開始，我們先從簡單的 bridge 模式開始，也就是，把所有 WiFi AP 的封包都導到 port 1 (連接至一個路由器)。 此模式並沒有用到 SDN (software-defined network) 的功能，只是純粹的把網路連載一起，所以不牽涉到 SDN controller 的設定，WiFi AP 也不需要安裝 SDN 的 client (例如: OpenFlow)。 ``` ovs-ofctl add-flow br0 "in_port=2,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=3,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=4,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=5,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=6,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=7,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=8,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=9,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=10,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=11,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=12,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=13,priority=1,actions=output:1"; ovs-ofctl add-flow br0 "in_port=14,priority=1,actions=output:1"; ``` 同時，對於從 port 1 來的資料，也都轉傳至每一個 WiFi AP。 ``` ovs-ofctl add-flow br0 "in_port=1,priority=1,actions=output:2, output:3, output:4, output:5, output:6, output:7, output:8, output:9, output:10, output:11, output:12, output:13, output:14" ``` 此指令是刪除所有的 flow 規則。 ``` ovs-ofctl del-flows br0 ``` 當然，我們也可以透過指令來查詢目前 flow 的設定。 ``` PICOS-OVS$ovs-ofctl dump-flows br0 NXST_FLOW reply (xid=0x4): flow_id=32, cookie=0x0, duration=28.464s, table=0, n_packets=n/a, n_bytes=0, idle_age=28, priority=1,in_port=5 actions=output:1 flow_id=34, cookie=0x0, duration=28.419s, table=0, n_packets=n/a, n_bytes=402, idle_age=5, priority=1,in_port=7 actions=output:1 flow_id=42, cookie=0x0, duration=23.149s, table=0, n_packets=n/a, n_bytes=1392, idle_age=4, priority=1,in_port=1 actions=output:2,output:3,output:4,output:5,output:6,output:7,output:8,output:9,output:10,output:11,output:12,output:13,output:14 flow_id=37, cookie=0x0, duration=28.372s, table=0, n_packets=n/a, n_bytes=0, idle_age=28, priority=1,in_port=10 actions=output:1 flow_id=31, cookie=0x0, duration=28.488s, table=0, n_packets=n/a, n_bytes=344, idle_age=1, priority=1,in_port=4 actions=output:1 flow_id=38, cookie=0x0, duration=28.357s, table=0, n_packets=n/a, n_bytes=274, idle_age=13, priority=1,in_port=11 actions=output:1 flow_id=33, cookie=0x0, duration=28.440s, table=0, n_packets=n/a, n_bytes=274, idle_age=13, priority=1,in_port=6 actions=output:1 flow_id=29, cookie=0x0, duration=28.524s, table=0, n_packets=n/a, n_bytes=402, idle_age=5, priority=1,in_port=2 actions=output:1 flow_id=35, cookie=0x0, duration=28.402s, table=0, n_packets=n/a, n_bytes=0, idle_age=28, priority=1,in_port=8 actions=output:1 flow_id=39, cookie=0x0, duration=28.342s, table=0, n_packets=n/a, n_bytes=274, idle_age=10, priority=1,in_port=12 actions=output:1 flow_id=36, cookie=0x0, duration=28.387s, table=0, n_packets=n/a, n_bytes=344, idle_age=1, priority=1,in_port=9 actions=output:1 flow_id=41, cookie=0x0, duration=28.310s, table=0, n_packets=n/a, n_bytes=274, idle_age=13, priority=1,in_port=14 actions=output:1 flow_id=40, cookie=0x0, duration=28.326s, table=0, n_packets=n/a, n_bytes=0, idle_age=28, priority=1,in_port=13 actions=output:1 flow_id=30, cookie=0x0, duration=28.510s, table=0, n_packets=n/a, n_bytes=1008, idle_age=4, priority=1,in_port=3 actions=output:1 ``` --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://openwrt-nctu.gitbook.io/project/experiment-sdn/pica8-setting.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.