Linux Routers and Community Networks

Summer Course at Mekelle Institute of Technology. July, 2015.

Linux Routers and Community Networks Llorenç Cerdà-Alabern http://personals.ac.upc.edu/llorenc [email protected] Universitat Politènica de Catalunya, Barcelona, Spain

Revision: 0e36644 (2015-07-09) Llorenç Cerdà-Alabern Linux Routers and Community Networks 1 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Introduction

Where I come from

Linux Routers Parts I Introduction II Lab 1: Basic Network Conﬁguration III Lab 2: RIP and OSPF IV Lab 3: Firewall conﬁguration V Lab 4: Community Networks VI Lab 5: Network Management

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Introduction

Where I come from Part I Linux Routers

Introduction

Outline

Where I come from Linux Routers

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Introduction Mekelle vs. Barcelona

Where I come from

Linux Routers

• Barcelona - Mekelle: 7,660 km Ethiopia Spain Tigray Catalonia Mekelle Barcelona Area [km2] 1.1 M 0.5 M 41 k 32 k 24.4 803 Population 90 M 47 M 4.3 M∗ 7.5 M 219 k 4.7 M

∗ 2007 Census. Source: Wikipedia.

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Introduction A bit of history: Barcino

Where I come from

Linux Routers

• Iberian, Carthaginian and Roman Town, called Barcino 15 BC.

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Introduction Barcelona

Where I come from

Linux Routers

Eixample Sagrada Familia Barça

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Introduction Universitat Politècnica de Catalunya (UPC)

Where I come from

Linux Routers

Campus Nord • UPC: Public University of Catalonia, focussed on tech. studies. • UPC has 22 Schools in 7 towns. • Facultat d’Informàtica de Barcelona (Computer Science) is in Campus Nord and has around 2,000 students.

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Introduction

Where I come from Part I Linux Routers

Introduction

Outline

Where I come from Linux Routers

Llorenç Cerdà-Alabern Linux Routers and Community Networks 8 / 191 Introduction Linux Routers

Introduction

Where I come from

Linux Routers

What is a Router? • Devices that use a common protocol: The Internet Protocol, IP. • Exchange Datagramans using any kind of physical network (LAN or WAN). • Interconnect IP Networks: Networks of devices having interfaces with unique addresses, sharing a common netid, or IP preﬁx (most signiﬁcant bits of the IP address).

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Introduction IPv4 address

Where I come from 0 bits 31 ++++++++++++++++ Linux Routers |netid| hostid| ++++++++++++++++

• 4 bytes (32 bits) • Dotted notation: 10.0.1.1, Mask: 255.255.255.0 or /24. • Host loopback network: 127.0.0.0/8. • Private add.: 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16. netid hostid Class (bytes) (bytes) Codiﬁcation range A 1 3 0xxxx x 0.0.0.0 127.255.255.255 ··· ∼ B 2 2 10xxx x 128.0.0.0 191.255.255.255 ··· ∼ C 3 1 110xx x 192.0.0.0 223.255.255.255 ··· ∼ D-- 1110x x 224.0.0.0 239.255.255.255 ··· ∼ E-- 1111x x 240.0.0.0 255.255.255.255 ··· ∼

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Introduction IPv6 address

Where I come 0 bits 127 from ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ | netid| hostid| Linux Routers ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

• 16 bytes (128 bits) • Notation: ff02:0000:0000:0000:0000:0000:0000:0001/64 (8 quads of 4 nibbles). Simpliﬁcation: supress leading and group zeroes: ff02::1/64 • Loopback: ::1/128 • Link local unicast: fe80::/10. Interface notation: fe80::4e5e:cff:fee9:fc89%eth0 • Unique local unicast (ULA): fc00::/7 (equivalent to private IPv4) • Global unicast: 2000::/3 • Multicast: ff00::/8 • Link local all nodes: ff02::1 Example: IPv6ll of all nodes in eth0: ping6 ff02::1%eth0 • Link local all routers: ff02::2 Llorenç Cerdà-Alabern Linux Routers and Community Networks 11 / 191 Introduction Linux Routers

Introduction How a router works

Where I come from

Linux Routers

~# route -n Kernel IP routing table Destination Gateway Genmask Metric Iface 0.0.0.0 10.1.24.97 0.0.0.0 30 eth1.3 10.1.24.96 0.0.0.0 255.255.255.224 30 eth1.3 ~# ip r l default via 10.1.24.97 dev eth1.3 proto static metric 30 10.1.24.96/27 dev eth1.3 proto static scope link metric 30

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Introduction

Commertial routers Where I come from

Linux Routers

CISCO Juniper

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Introduction SOHO routers

Where I come from

Linux Routers

CISCO Buffalo TP-link Mikrotik

Huawei Ubiquiti Zyxel D-link

···

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Introduction

Router Operating Systems Where I come from • CISCO: Internetwork Operating System, IOS. Linux Routers • Juniper: Junos OS. • Mikrotic: RouterOS. • Ubiquiti: AirOS. • Zyxel: ZyNOS. • Device speciﬁc: TP-Link, ··· • Unix/Linuxa: Alpine, NetBSD, DD-WRT, EdgeOS, FREESCO, FreeWRT, OpenWrt, Tomato, . ··· aSee Wikipedia: https://en.wikipedia.org/wiki/List_of_router_ and_firewall_distributions

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Introduction

Where I come from

Linux Routers

Why OpenWrt? • GNU/Linux distribution originally designed for embedded devices. • Free, open source. • Active web page with a lot of documentationa. • Continuously improved by a wide and very active community. • Supported by a large number of devicesb.

ahttps://openwrt.org/ bhttp://wiki.openwrt.org/toh/start

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Lab 1: Basic Network Conﬁguration

Description Parts Unix basic commands I Introduction Lab set up II Lab 1: Basic Network Conﬁguration Building a patch cord III Lab 2: RIP and OSPF Flashing OpenWrt IV Lab 3: Firewall conﬁguration Accessing OpenWrt V Lab 4: Community Networks Installing VI Lab 5: Network Management packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

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Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

Flashing Description Installing packages OpenWrt Accessing Unix basic commands OpenWrt Net. Interfaces OpenWrt Installing Lab set up Configure VLANs packages OpenWrt Net. Building a patch cord Configure WiFi Interfaces Configure Flashing OpenWrt VLANs Static Routing Configure Accessing OpenWrt WiFi

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Lab 1: Basic Network Conﬁguration

Description

Unix basic commands Objectives Lab set up • Basic Linux administration commands. Building a patch cord • Build a straight-through patch cord. Flashing OpenWrt • Install OpenWrt. Accessing • Conﬁguring networking interfaces and static routing. OpenWrt

Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

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Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

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Lab 1: Basic Network Conﬁguration Directories Description • cd: Change directory. Unix basic commands • mkdir: make directory, rmdir: remove directory. Lab set up • ls: list directory. Building a • patch cord rm: remove ﬁle, rm -r directory: remove directory and its

Flashing contents. OpenWrt • chown: change owner ﬁle/directory. Accessing OpenWrt • chmod: change permissions.

Installing Examples: chmod 700 file, chmod ugo+rwx file. packages • cat, more, less: dump ﬁle content. OpenWrt Net. Interfaces • df -h: list disk partitions.

Conﬁgure VLANs

Conﬁgure WiFi

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Lab 1: Basic Network Files Conﬁguration • grep: globally search regular expression (regex) and print,

Description ﬁlter ﬁle content using regex.

Unix basic ~# cat network | grep eth. commands option ifname ’eth0’ option ifname ’eth1’ Lab set up • find: find file. Examples: Building a patch cord ~# find . -name network ./config/network Flashing ./init.d/network OpenWrt ~# find /etc -name \*.conf -exec grep nameserver {} \; -print nameserver 127.0.0.1 Accessing /etc/resolv.conf OpenWrt Installing • sed: stream editor. packages ~# sed ’s/day/night/’ new OpenWrt Net. ~# iw wlan1 scan | sed -n /^BSS/,/SSID/p Interfaces BSS 02:ca:ff:ee:ba:be(on wlan1) -- joined TSF: 0 usec (0d, 00:00:00) Configure freq: 5825 VLANs ... last seen: 1687530 ms ago Configure SSID: qMp WiFi

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Lab 1: Basic Network Conﬁguration Processes Description • ps, top: show running processes. Unix basic • commands kill pid: kill process with process id pid.

Lab set up • killall cmd: kill command cmd. ~# top Building a Mem: 25404K used, 3608K free, 0K shrd, 964K buff, 4600K cached patch cord CPU: 1% usr 1% sys 0% nic 96% idle 0% io 0% irq 0% sirq Load average: 0.05 0.09 0.12 1/51 377 Flashing PID PPID USER STAT VSZ %VSZ %CPU COMMAND OpenWrt 8432 1 root S 2056 7% 1% /usr/sbin/bmx6 -f /etc/config/bmx6 -d Accessing 3 2 root SW 0 0% 0% [ksoftirqd/0] OpenWrt 27482 2 root SW 0 0% 0% [kworker/u2:2] 32763 32510 root R 1364 5% 0% top Installing 1200 1 root S 1360 5% 0% /usr/sbin/ntpd -n -p 0.openwrt.pool.n packages 32476 867 root S 1220 4% 0% /usr/sbin/dropbear -F -P /var/run/dro 923 1 root S 816 3% 0% /usr/bin/mini_snmpd -c public -d /jff OpenWrt Net. ... Interfaces ^C

Conﬁgure VLANs

Conﬁgure WiFi

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Lab 1: Basic Network Conﬁguration Basic editing with vi • Two modes of operation: Description • insert mode: enter text. Unix basic • command mode: issue editing commands. commands • To switch into insert mode: Lab set up i insert before cursor. Building a patch cord I insert beginning of line.

Flashing a append after cursor. OpenWrt A append at end of line. Accessing • To switch into command mode, press ESC. OpenWrt • Saving and exiting: Installing packages :q quit.

OpenWrt Net. :q! quit discarding changes. Interfaces :w save file. After each change, it is recommended to save (there is no Configure undo). To abort changes and quit :q!. VLANs :w file write to file. Configure WiFi

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Lab 1: Basic Network Basic editing with vi Conﬁguration • Deleting: x character. Description dw word. Unix basic commands dd line.

Lab set up • Copy paste: yy yank (copy) line Building a patch cord yw yank word

Flashing v starting point for yank (y) or delete (d). OpenWrt p paste word after cursor, or line below. Accessing P paste word before cursor, or line above. OpenWrt • Installing Moving: packages 0 beginning of line.

OpenWrt Net. $ end of line. Interfaces gg beginning of file. Configure G end of file. VLANs :n go to line n. Configure WiFi • Repeat command, e.g. remove 3 characters: 3x.

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ssh session to Lab 1: Basic configure the router Network Configuration OpenWrt Dropbear ssh server Description ssh and scp Unix basic commands • Configuration files:

Lab set up ~# ls ~/.ssh authorized_keys config id_rsa id_rsa.pub known_hosts Building a patch cord • Generates key pair (id_rsa, id_rsa.pub): Flashing ~# ssh-keygen-t rsa OpenWrt

Accessing • Connect to IP 192.168.1.1, user root: OpenWrt ~# ssh 192.168.1.1-l root Installing packages • ssh key pair can be used to connect without password appending _ _ OpenWrt Net. id rsa.pub to remote ﬁle .ssh/authorized keys: Interfaces ~# cat id_rsa.pub| ssh [email protected]’cat- >>.ssh/authorized _keys’ Conﬁgure VLANs • Recursively copy to remote host:

Conﬁgure ~# scp-r config [email protected]:/tmp WiFi

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Lab 1: Basic Network Conﬁguration Linux basic networking conﬁguration • List all interfaces: Description ~# ifconfig-a Unix basic commands • Assign IP address:

Lab set up ~# ifconfig eth0 102.168.1.2 netmask 255.255.255.240 Building a • List routing table: patch cord ~# route-n Flashing Kernel IP routing table OpenWrt Destination Gateway Genmask Flags Metric Ref Use Iface Accessing 0.0.0.0 192.168.2.1 0.0.0.0 UG 0 0 0 wlan0 OpenWrt 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 br-lan Installing • Add a default route: packages ~# route add default gw 192.168.2.1 OpenWrt Net. Interfaces • Add/delete a static route: Conﬁgure ~# route add-net 10.0.0.0 netmask 255.255.255.0 gw 192.168.2.1 VLANs ~# route del-net 10.0.0.0 netmask 255.255.255.0 gw 192.168.2.1

Conﬁgure WiFi

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Lab 1: Basic Network ip command Conﬁguration • Replaces and add functionalities to ifconfig and route.

Description # list IPv6 addresses root@OpenWrt:~# ip -6 a l Unix basic 1: lo: mtu 65536 commands inet6 ::1/128 scope host valid_lft forever preferred_lft forever Lab set up 2: eth0: mtu 1500 qlen 1000 inet6 fe80::12fe:edff:feaf:635e/64 scope link Building a valid_lft forever preferred_lft forever patch cord # assign an ip address root@OpenWrt:~# ip a a 192.168.50.5 dev eth1 Flashing # delete an ip address OpenWrt root@OpenWrt:~# ip a d 192.168.50.5 dev eth1 # list routing table Accessing root@OpenWrt:~# ip r l OpenWrt default via 147.83.34.2 dev eth1 Installing default via 147.83.34.2 dev eth1 proto static metric 1024 packages 147.83.34.0/24 dev eth1 proto kernel scope link src 147.83.34.125 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.10 OpenWrt Net. # adda routing table entry Interfaces root@OpenWrt:~# ip r a 10.10.20.0/24 via 192.168.1.1 dev eth0 # deletea routing table entry Conﬁgure root@OpenWrt:~# ip r d 10.10.20.0/24 via 192.168.1.1 dev eth0 VLANs # add default route root@OpenWrt:~# ip r a default via 192.168.1.1 Conﬁgure WiFi

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Lab 1: Basic Network Conﬁguration

Description arp Unix basic • List stations from the network with whom datagrams have commands been exchanged: Lab set up # legacy arp command Building a ~# arp patch cord IP address HW type Flags HW address Mask Device Flashing 192.168.1.234 0x1 0x2 00:24:e8:2c:74:e2 * br-lan OpenWrt 192.168.2.1 0x1 0x2 d4:ca:6d:a1:dc:e0 * wlan0 192.168.2.20 0x1 0x2 dc:9f:db:28:81:cd * wlan0 Accessing # using ip OpenWrt ~# ip neigh l 192.168.1.234 dev br-lan lladdr 00:24:e8:2c:74:e2 STALE Installing 192.168.2.1 dev wlan0 lladdr d4:ca:6d:a1:dc:e0 STALE packages 192.168.2.20 dev wlan0 lladdr dc:9f:db:28:81:cd STALE

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

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Lab 1: Basic Network Check for connectivity: ping, traceroute, mtr Conﬁguration • List stations from the network with whom datagrams have Description been exchanged:

Unix basic ~# ping 8.8.8.8 commands PING 8.8.8.8 (8.8.8.8): 56 data bytes 64 bytes from 8.8.8.8: seq=0 ttl=45 time=54.281 ms Lab set up 64 bytes from 8.8.8.8: seq=1 ttl=45 time=58.195 ms Building a ^C patch cord --- 8.8.8.8 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss Flashing round-trip min/avg/max = 54.281/56.238/58.195 ms OpenWrt ~# traceroute-n 8.8.8.8 traceroute to 8.8.8.8 (8.8.8.8), 30 hops max, 38 byte packets Accessing 1 10.228.205.1 5.807 ms 2.924 ms 2.875 ms OpenWrt 2 *** 3 10.253.4.22 5.145 ms 6.577 ms 6.800 ms Installing 4 62.115.43.113 8.434 ms 7.654 ms 4.084 ms packages 5 80.91.254.120 22.554 ms 80.91.253.97 22.552 ms 80.91.247.14 48.658 ms 6 62.115.143.210 34.897 ms 62.115.139.59 48.477 ms 80.91.246.182 46.697 ms OpenWrt Net. 7 62.115.134.65 67.621 ms 80.91.249.89 55.958 ms 213.155.134.114 54.432 ms Interfaces 8 80.91.253.54 48.835 ms 213.155.135.87 49.264 ms 213.155.135.83 47.000 ms Conﬁgure 9 213.248.85.118 45.592 ms 45.500 ms 50.965 ms VLANs 10 72.14.233.127 48.323 ms 54.649 ms 44.920 ms 11 8.8.8.8 45.559 ms 44.919 ms 45.512 ms Conﬁgure WiFi

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Lab 1: Basic Network Domain Name System, DNS Conﬁguration • File /etc/hosts:

Description ~# cat/etc/hosts 127.0.0.1 localhost Unix basic 127.0.1.1 tramuntana.local tramuntana commands 192.168.1.1 tp-link Lab set up • File resolv.conf: Building a ~# cat/etc/resolv.conf patch cord search lan nameserver 192.168.1.1 Flashing OpenWrt • File resolv.conf.auto: Accessing ~# cat/tmp/resolv.conf.auto OpenWrt # Interface wwan nameserver 212.68.193.110 Installing nameserver 212.68.193.196 packages

OpenWrt Net. • Asking the resolver with nslookup: Interfaces ~# nslookup Conﬁgure > set type=MX VLANs > cisco.com ... Conﬁgure WiFi

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Lab 1: Basic Network WiFi Review Conﬁguration • Use the Industrial Scientiﬁc and Medical (ISM) band: 2.4 GHz

Description and 5 GHz.

Unix basic • Basic Service Set (BSS): Set of stations communicating with commands each other. If the network is composed of more than 1 BSS it is Lab set up called Extended Service Set (ESS). Building a patch cord • BSS are identified by: (i) a Service Set identifier (SSID), or Flashing Network name: String with <32 characters; and (ii) a BSS OpenWrt Identifier (BSSID): 48 bits number. Accessing OpenWrt

Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs Infrastructure BSS Independent BSS, IBSS Conﬁgure (infrastructure mode). (ad-hoc mode). WiFi

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Lab 1: Basic Network Configuration WiFi Commands • Connected stations: iwinfo: Description ~# iwinfo wlan0 ESSID: "gubia" Unix basic Access Point: 0C:82:68:CD:A1:06 commands Mode: Client Channel: 11 (2.462 GHz) Tx-Power: 20 dBm Link Quality: 36/70 Lab set up Signal: -74 dBm Noise: unknown Building a Bit Rate: 48.0 MBit/s patch cord ... Flashing • Configuration and scanning: iw: OpenWrt ~# iw wlan0 scan Accessing BSS 0c:82:68:cd:a1:06(on wlan0) -- associated OpenWrt TSF: 60669050681 usec (0d, 16:51:09) freq: 2462 Installing beacon interval: 100 TUs packages capability: ESS Privacy ShortPreamble ShortSlotTime (0x0431) OpenWrt Net. signal: -72.00 dBm Interfaces last seen: 420 ms ago Information elements from Probe Response frame: Configure SSID: gubia VLANs ...

Conﬁgure WiFi

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Lab 1: Basic Network Troubleshooting Conﬁguration • tcpdump of a TCP segment: seq number payload length Description flags TCP seq number (bytes) next segment advertized dst port Unix basic src port window commands src IP address dst IP address timestamp Lab set up 16:43:02.126531 147.83.34.125.2628 > 147.83.30.137.80: S 903489440:903489440(0) win 5840 Building a MSS SACK window scale TCP options patch cord timestamp Flashing • Checking activity in eth0: OpenWrt ~# tcpdump-ni eth0 Accessing tcpdump: WARNING: eth0: no IPv4 address assigned OpenWrt tcpdump: verbose output suppressed, use -v or -vv for full protocol decode listening on eth0, link-type EN10MB (Ethernet), capture size 65535 bytes Installing 14:06:21.986572 IP 192.168.1.232.22 > 192.168.1.234.57951: Flags [P.], seq 3522875745:3522875797, ack 1450413287, win 2172, options [nop,nop,TS val 314333 ecr 1302433], length 52 packages ^C OpenWrt Net. Interfaces • Capturing dhcp packets in verbose mode:

Conﬁgure ~# tcpdump-vni br-lan port 67 VLANs tcpdump: listening on br-lan, link-type EN10MB (Ethernet), capture size 65535 bytes 14:24:56.571518 IP (tos 0x0, ttl 64, id 0, offset 0, flags [none], proto UDP (17), length 328) Conﬁgure 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request from 10:fe:ed:af:63:5e, length 300, xid 0x6aaf8c2c, Flags [none] WiFi ...

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Lab 1: Basic Network Conﬁguration Troubleshooting Description • System logs. In OpenWrt: Unix basic commands ~# logread Tue Jun 9 13:25:41 2015 daemon.notice netifd: Interface ’wwan’ is enabled Lab set up Tue Jun 9 13:25:41 2015 kern.info kernel: [ 1003.250000] wlan0: authenticate with 0c:82:68:cd:a1:06 ... Building a patch cord • netperf. Throughput of a link using the IPv6 link local with a Flashing OpenWrt 1 s test: ~# netperf-l1-H fe80::12fe:edff:feaf:635e%eth0 Accessing MIGRATED TCP STREAM TEST from ::0 (::) port 0 AF_INET6 to fe80::12fe:edff:feaf:635e%eth0 () port 0 AF_INET6 : demo OpenWrt Recv Send Send Socket Socket Message Elapsed Installing Size Size Size Time Throughput packages bytes bytes bytes secs. 10^6bits/sec OpenWrt Net. Interfaces 87380 16384 16384 1.05 92.75

Conﬁgure VLANs

Conﬁgure WiFi

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Lab 1: Basic Network Conﬁguration

Description

Unix basic commands Gnu screen Lab set up • Allows multiplexing a physical terminal in different windows. Building a patch cord Gnu screen initialization ﬁle:

Flashing ~# echo’caption always "%{= kw}%-w%{=BW}%n%t%{-}%+w %-=@%H-%LD%d%%LM-%c"’>.screenrc OpenWrt • The screen basic commands are the following (C-a c means Accessing OpenWrt type Control and a simultaneously, release and type c):

Installing C-a c create new window. packages C-d close window. OpenWrt Net. C-a 0 change to window number 0 (likewise for windows 0-9). Interfaces C-a p change to previous window. Conﬁgure C-a n change to next window. VLANs C-a k kill current window. Conﬁgure WiFi C-a A rename current window.

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Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

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G5 G6 Lab 1: Basic PC3 R5 R6 PC3 10.5.3.0/24 10.6.3.0/24 STAP ST ST Network PC2 .2 .1 .1 .2 PC2 CH132 10.5.2.0/24 .1 .1 10.6.2.0/24 .2 Conﬁguration .5 .1 .2 .5 .2 .1 .1 PC1 192.168.5.0/24 10.5.1.0/24 10.6.1.0/24 PC1 .2 .2

Description G4 G7 PC3 R4 R7 PC3 10.4.3.0/24 ST ST 10.7.3.0/24 Unix basic PC2 .2 .1 AP ST .1 .2 PC2 CH124 10.4.2.0/24 .1 .1 10.7.2.0/24 .2 commands Objectives: .4 .1 .2 .4 .2 .1 .1 PC1 192.168.4.0/24 10.4.1.0/24 10.7.1.0/24 PC1 Lab set up • We want to set up .2 .2

Building a G3 G8 this network. PC3 R3 R8 PC3 patch cord 10.3.3.0/24 ST ST 10.8.3.0/24 PC2 .2 .1 AP ST .1 .2 PC2 10.3.2.0/24 .1 CH116 .1 10.8.2.0/24 .2 Flashing .3.1 .2 .3 • Using static .2 .1 PC1 .1 OpenWrt 10.3.1.0/24 192.168.3.0/24 10.8.1.0/24 PC1 routing. .2 .2 Accessing OpenWrt G2 G9 • PC3 R2 R9 PC3 Following the 10.2.3.0/24 ST ST 10.9.3.0/24 Installing PC2 .2 .1 AP ST .1 .2 PC2 10.2.2.0/24 .1 CH108 .1 10.9.2.0/24 .2 .2 .1 .2 .2 packages guidelines in the .2 .1 PC1 .1 10.2.1.0/24 192.168.2.0/24 10.9.1.0/24 PC1 .2 .2 OpenWrt Net. next slides. Interfaces G1 G10 PC3 R1 R10 PC3 Conﬁgure 10.1.3.0/24 AP AP 10.10.3.0/24 PC2 .2 AP ST .2 .1 .1 PC2 VLANs 10.1.2.0/24 .1 CH100 .1 10.10.2.0/24 .2 .1 .1 .2 .1 .2 .1 .1 PC1 192.168.1.0/24 Conﬁgure 10.1.1.0/24 10.10.1.0/24 PC1 .2 CH1 CH6 .2 WiFi Internet .1 192.168.6.0/24 192.168.7.0/24 200.0.0.0/24 StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 38 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 39 / 191 Lab 1: Basic Network Conﬁguration Building a patch cord

Lab 1: Basic Network Conﬁguration

Description 12 3 4 8765

Unix basic commands Building a straight-through patch cord Lab set up Building a Pin Pair Cable Color patch cord 1 1 white/orange Flashing 2 OpenWrt 2 2 orange

Accessing 3 3 1 white/green OpenWrt 4 2 blue 1 Installing 5 1 white/blue packages 6 3 2 green OpenWrt Net. Interfaces 7 1 white/brown 4 Conﬁgure 8 2 brown VLANs

Conﬁgure Table: RJ45 EIA/TIA-568B pinout. WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 40 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 41 / 191 Lab 1: Basic Network Conﬁguration Flashing OpenWrt

Lab 1: Basic Network Conﬁguration 192.168.0.2/24 eth0

Description TL−WDR4300 router 192.168.0.1/24 Unix basic commands Flashing OpenWrt into TL-WDR4300 Lab set up

Building a 1 Download the OpenWrt image: patch cord https://downloads.openwrt.org/barrier_breaker/14.07/ar71xx/generic/ openwrt-ar71xx-generic-tl-wdr4300-v1-squashfs-factory.bin Flashing OpenWrt 2 Assign the IP address to the PC.

Accessing 3 Log into the WDR4300 at 192.168.0.1 using admin:admin OpenWrt 4 System Tools -> Firmware Upgrade. Installing 5 Browse -> packages select the firmware. 6 Upgrade -> OK. OpenWrt Net. Interfaces 7 You will then see the firmware upgrade in progress. Configure 8 After a couple of minutes this should switch to Software Upgraded VLANs Successfully! and restart. Configure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 42 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 43 / 191 Lab 1: Basic Network Conﬁguration Accessing OpenWrt

Lab 1: Basic Network ssh session to Conﬁguration configure the router

Description

Unix basic OpenWrt commands Dropbear ssh server

Lab set up Finding the local link local IPv6 Building a patch cord 1 Check the IPv6 link local of the local interface eth0: Flashing ~# ip -6 a l dev eth0 OpenWrt 2: eth0: mtu 1500 qlen 1000 inet6 fe80::250:daff:fec9:6ec7/64 scope link Accessing valid_lft forever preferred_lft forever OpenWrt

Installing 2 If no IPv6 link local is assigned, check that the kernel variable packages net.ipv6.conf.eth0.disable_ipv6 is set to 0: OpenWrt Net. _ Interfaces ~# sysctl -a | grep net.ipv6.conf.eth0.disable ipv6 net.ipv6.conf.eth0.disable_ipv6 = 1 Conﬁgure ~# sysctl -w net.ipv6.conf.eth0.disable_ipv6=0 VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 44 / 191 Lab 1: Basic Network Conﬁguration Accessing OpenWrt

Lab 1: Basic Network Conﬁguration Finding the OpenWrt router link local IPv6

1 ping to IPv6 multicast all hosts. Description ~# ping6 -c 2 ff02::1%eth0 Unix basic PING ff02::1%eth0(ff02::1) 56 data bytes commands 64 bytes from fe80::250:daff:fec9:6ec7: icmp_seq=1 ttl=64 time=0.027 ms 64 bytes from fe80::12fe:edff:feaf:635e: icmp_seq=1 ttl=64 time=0.279 ms (DUP!) Lab set up 64 bytes from fe80::250:daff:fec9:6ec7: icmp_seq=2 ttl=64 time=0.029 ms Building a patch cord --- ff02::1%eth0 ping statistics --- 2 packets transmitted, 2 received, +1 duplicates, 0% packet loss, time 999ms Flashing rtt min/avg/max/mdev = 0.027/0.111/0.279/0.118 ms OpenWrt 2 You can try to ping to IPv6 multicast all routers. Accessing OpenWrt ~# ping6 ff02::02%eth0 PING ff02::02%eth0(ff02::2) 56 data bytes Installing 64 bytes from fe80::12fe:edff:feaf:635e: icmp_seq=1 ttl=64 time=0.627 ms packages 64 bytes from fe80::12fe:edff:feaf:635e: icmp_seq=2 ttl=64 time=0.333 ms OpenWrt Net. ^C Interfaces --- ff02::02%eth0 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 999ms Conﬁgure rtt min/avg/max/mdev = 0.333/0.480/0.627/0.147 ms VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 45 / 191 Lab 1: Basic Network Conﬁguration Accessing OpenWrt

Lab 1: Basic Network Conﬁguration

Description

Unix basic Assign a password to the OpenWrt router commands 1 Assign a password to the OpenWrt router using telnet: Lab set up ~# telnet fe80::12fe:edff:feaf:635e%eth0 Building a root@OpenWrt:/# passwd patch cord Changing password for root New password: 13f Flashing Bad password: too short OpenWrt Retype password: 13f Accessing Password for root changed by root OpenWrt root@OpenWrt:/# ^D root@OpenWrt:/# Connection closed by foreign host. Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 46 / 191 Lab 1: Basic Network Conﬁguration Accessing OpenWrt

Lab 1: Basic Network Accessing the OpenWrt router with the command line interface Conﬁguration (CLI) and web interface (WI)

Description 1 We need to forward ports with ssh to access with the WI.

Unix basic ~# ssh -L 8080:[::1]:80 fe80::12fe:edff:feaf:635e%eth0 -l root commands The authenticity of host ’fe80::12fe:edff:feaf:635e%eth0 (fe80::12fe:edff:feaf:635e%eth0)’ can’t be established. RSA key fingerprint is b1:b5:d3:f0:1b:03:5c:dc:ff:bd:2a:c5:14:45:c3:76. Lab set up Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added ’fe80::12fe:edff:feaf:635e%eth0’ (RSA) to the list of known hosts. Building a root@fe80::12fe:edff:feaf:635e%eth0’s password: 13f patch cord

Flashing 2 Use the URL http://localhost:8080 to access the WI with the OpenWrt browser. Accessing OpenWrt

Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 47 / 191 Lab 1: Basic Network Conﬁguration Accessing OpenWrt

Lab 1: Basic Network Conﬁguration Disable the ﬁrewall using the WI System -> Startup -> firewall -> Enable & Stop Description

Unix basic commands

Lab set up

Building a patch cord Conﬁgure the router name Flashing OpenWrt System -> Hostname -> Save & Apply Accessing OpenWrt

Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 48 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 49 / 191 Lab 1: Basic Network Conﬁguration Installing packages

Lab 1: Basic Network Conﬁguration 1 Connect the Internet Ethernet port of the router to the Internal network. The router should be conﬁgured by DHCP and have Description access to the Internet. Unix basic commands 2 Install the packages: tcpdump, ip, netperf and screen. Lab set up System -> Software -> Update list -> Find Building a patch cord

Flashing OpenWrt

Accessing OpenWrt

Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs 3 Activate the netperf server: System -> Startup... Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 50 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 51 / 191 Lab 1: Basic Network Conﬁguration OpenWrt Net. Interfaces

Lab 1: Basic Network Conﬁguration Linux kernel distinguishes two type of interfaces 1 Physical Network Interfaces: As soon as the device driver is Description loaded into the Kernel a corresponding physical network Unix basic interface becomes present, e.g. eth0, wlan0, etc. commands 2 Virtual Network Interfaces: Introduced for the sake of ﬂexibility. Lab set up Associated with a physical network interface, another virtual Building a patch cord interface, or be stand alone such as the loopback interface lo.

Flashing OpenWrt • The Unified Configuration Interface, UCI, is a small C utility Accessing OpenWrt designed to centralize configuration in OpenWrt. Installing • /etc/config/network is the network configuration file. packages

OpenWrt Net. • /etc/config/wireless is the wireless configuration file. Interfaces • UCI creates an abstraction layer for configuring network interfaces: Configure VLANs In /etc/config/network you allocate a name like lan or wan. Then

Conﬁgure this name is consistently used through the entire UCI conﬁguration. WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 52 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 53 / 191 Lab 1: Basic Network Conﬁguration Conﬁgure VLANs

Lab 1: Basic Network Conﬁguration What are VLANs?

Description

Unix basic commands

Lab set up

Building a patch cord Flashing • OpenWrt Each port belongs to a VLAN.

Accessing • The switch isolates different VLANs: Each VLAN is equivalent OpenWrt to a different physical switch. A router is needed to send trafﬁc Installing packages to a different VLAN.

OpenWrt Net. • The port configured as trunk belongs to several VLANs. Interfaces • The traffic sent in one VLAN is also sent to the trunk the VLAN Configure VLANs belongs to. A tagging mechanism is used in the trunk to

Conﬁgure discriminate the trafﬁc from different VLANs. WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 54 / 191 Lab 1: Basic Network Conﬁguration Conﬁgure VLANs

Lab 1: Basic Network Conﬁguration

Default TP-Link TL-WDR4300 VLAN conﬁguration Description

Unix basic commands

Lab set up

Building a patch cord

Flashing OpenWrt eth0.1 eth0.2 not used Accessing OpenWrt

Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 55 / 191 Lab 1: Basic Network Conﬁguration Conﬁgure VLANs

Lab 1: Basic Network Conﬁguration

Description 1 Using the WI, conﬁgure Ethernet ports 1, 2, 3, 4 of the router in

Unix basic VLANs 1, 2, 3, 4, and the Internet port in VLAN 5. Note that commands originally the Internet port of the router is conﬁgured in VLAN 2. Lab set up Network -> Switch -> Add -> -> Save & Apply Building a ··· patch cord

Flashing OpenWrt

Accessing OpenWrt

Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 56 / 191 Lab 1: Basic Network Conﬁguration Conﬁgure VLANs

Lab 1: Basic Network Create Interfaces for the VLANS Conﬁguration 1 Using the WI, create the virtual interfaces LAN1, LAN2, LAN3, LAN3 eth0.1 eth0.2 Description associated with physical interfaces , , eth0.3, eth0.4. Conﬁgure them with unmanaged protocol. Unix basic commands Associate the wan interface with eth0.5. In the end, delete the LAN Lab set up interface, reboot and connect again. The new interfaces should show

Building a up configured only with IPv6 link local addresses: patch cord root@OpenWrt:~# reboot; exit Flashing ~# ssh -L 8080:[fe80::12fe:edff:feaf:635e%eth0]:80 fe80::12fe:edff:feaf:635e%eth0 -l root OpenWrt root@OpenWrt:~# ipal ... Accessing 5: eth0.1@eth0: mtu 1500 qdisc noqueue state UP group default OpenWrt link/ether 10:fe:ed:af:63:5e brd ff:ff:ff:ff:ff:ff inet6 fe80::12fe:edff:feaf:635e/64 scope link Installing valid_lft forever preferred_lft forever packages 6: eth0.2@eth0: mtu 1500 qdisc noqueue state UP group default link/ether 10:fe:ed:af:63:5e brd ff:ff:ff:ff:ff:ff OpenWrt Net. inet6 fe80::12fe:edff:feaf:635e/64 scope link Interfaces valid_lft forever preferred_lft forever 7: eth0.3@eth0: mtu 1500 qdisc noqueue state UP group default Configure link/ether 10:fe:ed:af:63:5e brd ff:ff:ff:ff:ff:ff VLANs inet6 fe80::12fe:edff:feaf:635e/64 scope link _ _ Configure valid lft forever preferred lft forever _ WiFi 8: eth0.4@eth0: mtu 1500 qdisc noqueue state UP group default link/ether 10:fe:ed:af:63:5e brd ff:ff:ff:ff:ff:ff StaticLlorenç Routing Cerdà-Alabern inet6 fe80::12fe:edff:feaf:635e/64Linux Routers andscope Community link Networks 57 / 191 valid_lft forever preferred_lft forever ... Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 58 / 191 Lab 1: Basic Network Conﬁguration Conﬁgure WiFi

Lab 1: Basic Network Conﬁguring a WiFi AP Conﬁguration 1. Network -> wifi -> Edit 2. Advanced Settings

Description

Unix basic commands

Lab set up

Building a patch cord

Flashing OpenWrt

Accessing OpenWrt 3. Save & Apply, Enable See appendix A for channels. Installing packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 59 / 191 Lab 1: Basic Network Conﬁguration Conﬁgure WiFi

Lab 1: Basic Network Configuring a wifi station Configuration 1. Network -> wifi 2. scan

Description

Unix basic commands

Lab set up

Building a patch cord

Flashing OpenWrt

Accessing OpenWrt Installing 3. Join Network 4. submit. packages

OpenWrt Net. Interfaces

Conﬁgure VLANs

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 60 / 191 Summer Course at Mekelle Institute of Technology. Linux Routers and Community Networks

Lab 1: Basic Network Part II Conﬁguration

Description Lab 1: Basic Network Conﬁguration Unix basic commands

Lab set up

Building a Outline patch cord

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 61 / 191 Lab 1: Basic Network Conﬁguration Static Routing

Lab 1: Basic Network Conﬁguration Conﬁguration of IP addresses and routing tables

Description 1 Use the CLI to conﬁgure the IP addresses and router table

Unix basic entries. Try with traditional commands (ifconfig, route), and commands ip command. Lab set up 2 Conﬁgure the PCs manually (with ip command), setting the Building a patch cord router where they are connected as default gateway. Flashing OpenWrt 3 Each router must end up with the 37 networks and a default Accessing route towards the laptop that represents the Internet. All hosts OpenWrt must be reachable. Installing packages 4 Convection for the gateways: a router in the same column to OpenWrt Net. reach networks in the same side, a router in the same row to Interfaces reach networks in the opposite side. For instance, R1 chooses Conﬁgure VLANs R5 to reach 10.5.1.0/24, and R10 to reach 10.6.1.0/24.

Conﬁgure WiFi

StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 62 / 191 Lab 1: Basic Network Conﬁguration Static Routing

Description G4 G7 PC3 R4 R7 PC3 10.4.3.0/24 ST ST 10.7.3.0/24 Unix basic PC2 .2 .1 AP ST .1 .2 PC2 CH124 10.4.2.0/24 .1 .1 10.7.2.0/24 .2 commands .4 .1 .2 .4 .2 .1 .1 PC1 192.168.4.0/24 10.4.1.0/24 10.7.1.0/24 PC1 Lab set up .2 .2 Objectives: Building a G3 G8 patch cord PC3 R3 R8 PC3 • We want to set up 10.3.3.0/24 ST ST 10.8.3.0/24 PC2 .2 .1 AP ST .1 .2 PC2 10.3.2.0/24 .1 CH116 .1 10.8.2.0/24 .2 Flashing .3.1 .2 .3 .2 .1 PC1 .1 OpenWrt this network. 10.3.1.0/24 192.168.3.0/24 10.8.1.0/24 PC1 .2 .2 Accessing • Using static OpenWrt G2 G9 PC3 R2 R9 PC3 routing. 10.2.3.0/24 ST ST 10.9.3.0/24 Installing PC2 .2 .1 AP ST .1 .2 PC2 10.2.2.0/24 .1 CH108 .1 10.9.2.0/24 .2 .2 .1 .2 .2 packages .2 .1 PC1 .1 10.2.1.0/24 192.168.2.0/24 10.9.1.0/24 PC1 .2 .2 OpenWrt Net. Interfaces G1 G10 PC3 R1 R10 PC3 Conﬁgure 10.1.3.0/24 AP AP 10.10.3.0/24 PC2 .2 AP ST .2 .1 .1 PC2 VLANs 10.1.2.0/24 .1 CH100 .1 10.10.2.0/24 .2 .1 .1 .2 .1 .2 .1 .1 PC1 192.168.1.0/24 Conﬁgure 10.1.1.0/24 10.10.1.0/24 PC1 .2 CH1 CH6 .2 WiFi Internet .1 192.168.6.0/24 192.168.7.0/24 200.0.0.0/24 StaticLlorenç Routing Cerdà-Alabern Linux Routers and Community Networks 63 / 191