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docs:guide-user:network:wifi:dumbap [2018/08/31 20:28] – disable dnsmasq service if not required; disable odhcpd service to avoid running DHCPv6 burghardtdocs:guide-user:network:wifi:dumbap [2024/02/01 19:55] – [Wireless Access Point (aka "Dumb" Access Point)] intro should be concise palebloodsky
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-====== Dumb AP / Access Point Only ======+====== Wireless Access Point (aka "DumbAccess Point======
  
-This document describes how to create an Access Point (AP)  +This page describes how to configure your device as a //wireless access point (AP)//, sometimes called //"dumb AP"// connected to an existing network with a single main routerThe term //dumb// is used since the AP will not provide administrative duties such as routing, firewall, DHCP, or DNS, as these will be performed by the main router or other device.
-that extends network that already has a router, access control, and DHCP in place. +
-People can connect over wireless or Ethernet to the new AP and then to the existing network.  +
-In this configuration, the AP is not routing packetsit does not provide DHCP or other functions. +
-The result is a bridged LAN (no internal subnets) that will work fine for home and small networks.+
  
-//Note:// The AP wireless can be configured to control access as Open/WPA/WPA2/etcMAC-based access control is controlled by the main router+One common reason for this is to add additional wireless coverage to an existing network, maybe on a different floor or to cover a wireless dead spotThis setup is sufficient for small home or office network, but for larger networks a more sophisticated approach is often used.
  
-//Note:// 'Static DHCP' is not covered here: this procedure creates an AP that provides wired/wireless access and won't interfere with Static DHCP.+<WRAP box> 
 +Summary of configuration for a Wireless AP: 
 +  - The wireless AP is connected LAN-to-LAN to the main router by some means e.g. ethernet cable, 802.11s mesh, etc.  
 +  - The wireless AP bridges its SSID wireless interface onto its LAN bridge interface. Wireless traffic on the wireless AP goes to its bridge LAN interface, then to the main router. 
 +  - The wireless AP bridge LAN may have either a static or DHCP address on the same subnet as the main router bridge LAN interface. 
 +  - The wireless AP gateway IP address is set to the address of the main router, either in the configuration or by DHCP. 
 +  - The wireless AP does not provide DHCP service, DNS resolution, or a firewall. 
 +</WRAP>
  
-//NoteThis recipe is similar to the "Bridged AP" recipe at [[docs:guide-user:network:wifi:BridgedAP|Bridged AP]]. These pages should probably be merged.//+{{section>meta:infobox:howto_links#config-network-device&noheader&nofooter&noeditbutton}}
  
-===== Configuration via Web Interface LUCI =====+===== External Videos for Reference =====
  
-Of course you can achieve this with using the web interface:\\ +Several videos are available on the topic which may be useful for background information.\\ 
-Once you have configured your wireless network with LUCI you can start configuring your dumb AP.\\ +Bare in mind they are somewhat outdated and generally do not take into account everything.
-  - Disconnect the (soon-to-be) Dumb AP from your network, and connect your computer to it with an Ethernet cable. \\ +
-  - Use the web interface to go to Network -> Interfaces and select the LAN interface.\\ +
-  - Enter an IP address "next to" your main router on the field "IPv4 address". (If your main router has IP 192.168.1.1, enter 192.168.1.2). Set DNS and gateway to point into your main router to enable internet access for the dumb AP itself \\ +
-  - Then scroll down and select the checkbox "Ignore interface: Disable DHCP for this interface."\\ +
-  - In the top menu go to System -> Startup, and disable Firewall in the list of startup scripts.\\  +
-  - Click the Save and Apply button. Hard-Restart your router if you're not able to connect anymore.\\ +
-  - Go to http://192.168.1.2 (or whatever address you specified) and check if the settings for the LAN interface are the same.\\ +
-  - Use an Ethernet to connect one of the LAN ports on your main router to one of the LAN/switch ports of your "new" dumb AP. (There's no need to connect the WAN port of the Dumb AP.) +
-  - You are done.\\+
  
 +Using OpenWrt v21 with DSA example:
  
-===== Configuration via command line tools =====+{{youtube>qeuZqRqH-ug?}} 
 + 
 +Two videos which are outdated but explain firewall and APs: 
 + 
 +{{youtube>UvniZs8q3eU?}} 
 +{{youtube>4t_S2oWsBpE?}} 
 + 
 +WiFi roaming is much improved in newer mobile devices so configuring Fast Roaming, aka 802.11r, may not be required.\\ 
 +This video can be misleading as 802.11r has nothing to do with mesh networking. 
 +{{youtube>kMgs2XFClaM?}} 
 + 
 +===== Configuration via LuCI ===== 
 + 
 +These instructions refer to the interface found in OpenWrt 23.05. The interface of v21 upwards differs in significant ways from earlier versions of OpenWrt which we try to account for... but no guarantees. 
 + 
 +This setup requires two routers, a computer with an Ethernet port, and an Ethernet cable.  We refer to the routers as the //main router// and the //wireless AP// and we assume default settings on both.  The main router should already be properly configured and connected to the Internet. 
 + 
 +Disconnect the wireless AP from your network.\\ 
 +Use an Ethernet cable to connect your computer to one of the LAN ports (not the //Internet/////WAN// port) of the wireless AP.\\ 
 +If you use a notebook, turn off WiFi while configuring your AP to only have one IP connection, a wired one, to your "to be" configured wireless AP.\\ 
 +From a browser, navigate to LuCI by going to http://192.168.1.1. Login. Change the admin password if necessary.\\ 
 +   
 +{{:media:docs:howto:dumbap_1_interface_overview.jpg?750|}}   
 +  
 +Go to //Network -> Interfaces// and click on the **Edit** button of the LAN interface.  Ensure you are on the //General Settings// tab. 
 + 
 +{{:media:docs:howto:dumbap_2_interface_changed.jpg?750|}} 
 +  
 +It is best to configure the wireless AP to use DHCP to obtain an address from the main router,\\ 
 +but this guide will show how to do it the alternative way - by configuring a static IP address.\\ 
 + 
 +Give the wireless AP an IP address "next to" your main router.\\ 
 +By default, the main router will have an address of 192.168.1.1, so use 192.168.1.2. (or something like that.) \\ 
 +The address should be on the same subnet as your main router but out of the DHCP range used when assigning addresses to connected devices.\\ 
 +By default, that means the wireless AP router IP should be between 192.168.1.2 and 192.168.1.100.\\ 
 +If you're adding multiple wireless APs, you could use 192.168.1.3, 192.168.1.4, etc.\\ 
 +Save and apply the new IP address. 
 +   
 +{{:media:docs:howto:dumbap_3_connectivity.jpg?750|}} 
 +     
 +A warning screen will apear because you changed the routers IP to 192.168.1.2. Press "Apply and keep settings"
 +      
 +Navigate back to the address you assigned in the previous step (say, http://192.168.1.2).\\ 
 +Make sure your browser uses the new IP address you assigned in the previous step. \\ 
 +Why?  Because in the next step, the gateway needs to be changed to point to the main router, and LuCI will not allow you to change the gateway to 192.168.1.1 while the wireless AP router is using that IP address.\\ 
 +If things are not working as expected, unplug the network cable from your computer for 10 seconds and plug in again. The currently still active DHCP Server on your wirless AP will then reasign a valid IP to you. \\  
 + 
 +Login in your router and go back to //Network -> Interfaces//, **Edit** the //LAN interface//, //General Settings// tab.\\ 
 + 
 +{{:media:docs:howto:dumbap_4_gateway.jpg?750|}} 
 +   
 +Change the IPv4 gateway to point to your main router, 192.168.1.1 by default.  This sets the wireless AP router to use the main router for Internet access.\\ 
 +   
 +{{:media:docs:howto:dumbap_5_dns.jpg?750|}} 
 +   
 +Use the main router (192.168.1.1) for DNS.  Same page but the //Advanced Settings// tab.  Enter the IP of your main router in the //Use custom DNS servers// field and click //+//. 
 +   
 +{{:media:docs:howto:dumbAP_6_DHCP.jpg?750|}} 
 +   
 +Use the main router for DHCP (and disable DHCP for the Wireless AP).  Same page again, now the //DHCP Server// tab.  Ensure the //Ignore interface// checkbox is checked.\\ 
 +   
 +{{:media:docs:howto:dumbAP_7_DHCP_ip6.jpg?750|}} 
 +   
 +Disable IPv6 DHCP.  Same page, //DHCP Server// tab again, but click on the //IPv6 Settings// sub-tab.  Set the //RA-Service//, //DHCPv6-Service//, and //NDP-Proxy// dropdowns to //disabled//.\\   
 +**In versions of OpenWrt older than 21.02.0:**  Under "Physical Settings" tab, ensure "Bridge interfaces" is ticked, and ensure BOTH of your interfaces (eth0, wlan0) are selected, in order to allow traffic between wireless and wired connections.\\ 
 +Press "Save"  
 +   
 +{{:media:docs:howto:dumbAP_8_DHCP_sanda.jpg?750|}} 
 +   
 +On the "Interface" screen, press "Save & Apply".\\ 
 +Most important steps are done, your wireless AP works!\\ 
 + 
 +Review next steps for some fine tuning, enable WLAN or even add a Guest Network:\\ 
 + 
 +If you plan to add a "GUEST" network on your wireless AP (see this guide: [[:docs:guide-user:network:wifi:guestwifi:guestwifi_dumbap]]), \\ 
 +**do not** do the next steps regarding turning off services labeled //firewall//, //dnsmasq// and //odhcpd// because your GUEST network will need these.\\ 
 +Deleting the WAN / WAN6 interfaces is compatible with having a GUEST network on your wireless AP. 
 +   
 + - To save resources on the wireless AP router, disable unneeded services.  Navigate to //System -> Startup// Disable the services labeled //firewall//, //dnsmasq// and //odhcpd// (Perhaps ironically, click **Enable** to toggle.)  //Note even though these services are now disabled, after you flash a new image to the device they will be re-enabled.//  For a more permanent fix see [[#Disable Daemons Persistently]].\\ 
 + - Optionally, remove or disable the //WAN// and //WAN6// interfaces.  On the //Network -> Interfaces// page, **Edit** the //WAN// and //WAN6// interfaces to uncheck the //Bring up on boot// checkbox.  Or just delete the interfaces.    \\ 
 + - //Note that by default OpenWrt does not enable wireless access.//  So, from a default installation, at the very least you will need to review the wireless SSIDs, enable wireless security, and then enable the wireless networks from the //Network -> Wireless// page. 
 +Click the //Save and Apply// button.\\ 
 + 
 +Use an Ethernet cable to connect one of the LAN ports on your main router to one of the LAN ports (**not** the //WAN/////Internet// port) of the wireless AP router. 
 +You may need to reboot or power cycle either or both routers, the device connecting your main router to the Internet, and potentially any connected devices.  In many cases this will not be necessary. 
 +Done!\\ 
 + 
 +===== Configuration via OpenWrt command line tools =====
  
 The changes below assume an OpenWrt default configuration, the relevant files are: The changes below assume an OpenWrt default configuration, the relevant files are:
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         option type     'bridge'         option type     'bridge'
         option ifname   'eth0.1 eth1'  # Bridges vlan 1 and wan         option ifname   'eth0.1 eth1'  # Bridges vlan 1 and wan
-        option proto    'dhcp'         # Change as appropriat+        option proto    'dhcp'         # Change as appropriate
 </code> </code>
  
-Switch configuration on WR1043ND (barrier breaker):+Switch configuration on WR1043ND (barrier breaker).
  
 <code> <code>
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         option ifname   'eth0.1'               option ifname   'eth0.1'      
         option proto    'dhcp'         # Change as appropriate         option proto    'dhcp'         # Change as appropriate
 +</code>
 +
 +=== Switch and dedicated WAN devices post 21.01 ===
 +The syntax is slightly different for these devices. You will notice that there is a config device which lists the ethernet port(s) assigned to an interface (in this case the br-lan). It will also list the assigned port under the "list ports" clause. The gotcha here is that you must add a separate line for each "list ports" added to a device. If you try to add them to one "list ports" entry space or comma separated it will not work properly. Finally you can remove/comment out any WAN interface settings identical to the above entries.
 +<code>config device
 + option name 'br-lan'
 + option type 'bridge'
 + list ports 'eth0'
 + list ports 'eth1'
 +
 +config interface 'lan'
 + option device 'br-lan'
 + option proto 'static'
 + option netmask '255.255.255.0'
 + option ipaddr '192.168.1.1'
 </code> </code>
  
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 Disable [[docs:techref:odhcpd|odhcpd]] with uci: Disable [[docs:techref:odhcpd|odhcpd]] with uci:
 <code>uci set dhcp.lan.dhcpv6=disabled <code>uci set dhcp.lan.dhcpv6=disabled
 +uci set dhcp.lan.ra=disabled
 uci commit uci commit
 </code> </code>
Line 142: Line 240:
 <code>/etc/init.d/firewall disable <code>/etc/init.d/firewall disable
 /etc/init.d/firewall stop</code> /etc/init.d/firewall stop</code>
 +
 +==== Step 6: Disable wpa_supplicant (if no STA WiFi interfaces) ====
 +
 +<code>rm /usr/sbin/wpa_supplicant</code>
  
 ===== Apply changes ===== ===== Apply changes =====
  
-Reloading the network config should be enough, it should automatically restart if necessary.+Reloading the network config should be enough, it should automatically restart if necessary. Or just reboot.
  
 <code>/etc/init.d/network reload</code> <code>/etc/init.d/network reload</code>
  
 ===== IPv6 ===== ===== IPv6 =====
 +If you would like your AP to receive IPv6 as a host only and not for routing you have to tell the DHCPv6 client not to request prefix delegation.
 +If you do not do this the AP will reject basic IPv6 addresses.
 +If you want to still be able to use IPv6 on the router itself change the ''wan6'' to ''lan6'' and ''@wan'' to ''@lan''.
  
-If you would like your AP to receive IPv6 as a host only and not for routing you have to tell dhcp6c not to request prefix deligation.  If you do not do this the AP will reject basic IPv6 addresses. +<code> 
-If you want to still be able to use ipv6 on the Router itself change the wan6 to lan6 and @wan to @lan +config interface 'lan6'
- +
-<code>config interface 'lan6'+
  option proto 'dhcpv6'  option proto 'dhcpv6'
  option ifname '@lan'  option ifname '@lan'
- option reqprefix no</code>+ option reqprefix 'no
 +</code> 
 + 
 +===== Disable Daemons Persistently ===== 
 +Note that although the start-up of daemons such as firewall, dnsmasq, wpa_supplicant and optionally odhcpd have been set to disabled, when a new image is flashed to the device, they will be re-enabled.  To work-around this, simply add the following to ''/etc/rc.local'' on the device: 
 +<code> 
 +# these services do not run on dumb APs 
 +for i in firewall dnsmasq odhcpd; do 
 +  if /etc/init.d/"$i" enabled; then 
 +    /etc/init.d/"$i" disable 
 +    /etc/init.d/"$i" stop 
 +  fi 
 +done 
 + 
 +rm /usr/sbin/wpa_supplicant 
 +</code> 
 + 
 +===== Populate Hostnames in Associated Stations ===== 
 +Dumb APs will not have the data to display hostnames of the associated devices.  Only MAC addresses are known to it.  Users wanting to see the corresponding hostnames in the Associated Stations display in LuCI can manually populate ''/etc/ethers'' on the dumb AP: 
 + 
 +On the router, one can extract this data with the following one-liner: 
 +<code> 
 +< dhcp.leases | awk '{print $2" "$4}' 
 +</code> 
 + 
 +See the following discussion threads for additional approaches: 
 +  * Using fping to populate ethers file: https://forum.openwrt.org/t/associated-stations-list-in-ap-how-to-show-host-names/63475/
 +  * An improved fping approach: https://forum.openwrt.org/t/second-device-not-getting-dns-entries-from-first-device-to-show-in-associated-stations/57005/14 
 +  * Propagating dhcp.leases to secondary (dumb) access points: https://forum.openwrt.org/t/associated-stations-making-hostnames-visible-across-multiple-aps/92593 
 + 
 + 
 +===== Multicast ===== 
 + 
 +DLNA and UPnP clients, and printer or SMB discovery protocols tend to work by using multicast packets. For example PlayStation, Xbox, and TVs use DLNA to detect, communicate with and stream audio/video over the network. By default on bridged interfaces on OpenWrt multicast snooping is turned off. This means all network interfaces connected to a bridge (such as a WiFi SSID and ethernet VLAN) will receive multicast packets as if they were broadcast packets.
  
-===== Multicast Forwarding =====+On WiFi the //slowest// modulation available is used for multicast packets (so that everyone can hear them). If you have "enabled legacy 802.11b rates" on your WiFi (Advanced settings checkbox in LuCI under the WiFi settings, or ''option legacy_rates '1''' in /etc/config/wireless file) then 1Mbps is the rate that will be used. This can completely use up the WiFi airtime with even fairly light multicast streaming. 
  
-Multicast forwarding is necessary for DLNA and UPnP clients to work properlyFor example PS3xboxTVs and stereos use DLNA to detectcommunicate with and stream audio/video over the network. Since multicasting is turned off (multicast snooping is turned onby default in newer OpenWrt releases, it must be activatedThis would forward any multicast packets to all ports allowing your TV to find your DLNA capable NAS with movies. In large networks, this could cause some overhead which may not be desirable.+There are two possible fixes for this, one is to //enable// multicast snooping: ''option igmp_snooping '1''' under the appropriate /etc/config/network settings for the bridge. This will cause the bridge to forward only on bridge ports that have requested to receive the particular multicast groupOn the other handif someone on WiFi requests the groupit will still flood the multicast thereand some people have reported problems with certain devices such as android phones and with ipv6 when igmp_snooping is enabled (requires further debugging to identify if there is really a problem or not). By //disabling// legacy 802.11b rates (''option legacy_rates '0''') you can at least force the use of 6Mbps or more on the WiFi multicast packets, and this opens up more airtime for other uses
  
-Add this into /etc/rc.local +==== Notes: ====
-<code>echo "0" > /sys/devices/virtual/net/br-lan/bridge/multicast_snooping</code> +
-Replace **br-lan** with your actual bridge interface, sometimes also called **br0**.+
  
-This will forward all multicast packets to all ports on your bridge, making igmpproxy or udpxy proxies unnecessary+  * //Dumb AP wireless can be configured to control access as Open/WPA/WPA2/etc. MAC-based access control is controlled by the main router.// 
 +  * //'Static DHCP' is not covered here: this procedure creates an AP that provides wired/wireless access and won't interfere with Static DHCP.// 
 +  * //This recipe is similar to the "Bridged AP" recipe at [[docs:guide-user:network:wifi:BridgedAP|Bridged AP]]. These pages should probably be merged.// 
 +  * //Firewall bridge mode support in OpenWrt is provided by the [[packages:pkgdata:kmod-br-netfilter|kmod-br-netfilter]] module.//
  
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