Guest Network
From DD-WRT Wiki
Contents |
Introduction
A Guest Network is a separate SSID (wireless network ID) using a virtual access point (VAP) that gives guest access to the WAN (internet) while blocking them from your LAN (local network), thereby protecting your security.
- Also see Multiple_WLANs
New DNSMasq Method
This uses the "23020 and later" method, but with dnsmasq instead of dhcpd. For a Wireless Access Point (WAP), Multiple DHCP Server is not available with the WAN disabled. See the VAP on an Access Point section below.
- Services -> Services-> DNSMasq: Enable DNSMasq but leave other options disabled
- In Additional DNSMasq Options, add the IP address and range for the appropriate virtual guest interface
- Example for Broadcom (5 GHz is wl1.1), Atheros is usually ath0.1 or ath1.1, but depends on the router:
interface=wl0.1 dhcp-option=wl0.1,3,192.168.7.1 dhcp-range=wl0.1,192.168.7.2,192.168.7.60,255.255.255.0,12h
23020 and later
Kong added easy Guest Network capability to DD-WRT, starting with build 23020.
- Firewall changes should not be needed for a normal gateway router setup
Wiki setup instructions: Guest WiFi + abuse control for beginners
Prior to 23020
Reference: DD-WRT Guest Wireless
- Section Wireless -> Basic Settings tab
- “Add” a “Virtual Interface”, give this guest network a separate SSID, and “Enable” “AP Isolation”.
- Click Save, then Apply
- Wireless Security tab: also use a separate password, and WPA2 AES security
- Click Save, then Apply
- Section Setup -> Networking tab
- Under “Create Bridge” click “Add”, name it, then set a different subnet
- Under “Assign to Bridge” click “Add", select the new bridge, then assign it to the new virtual interface
- Click Save, then Apply
- Networking tab: under “Multiple DHCP Server” click “Add” and select the new bridge
- Click Save, then Apply
- Section Administration -> Commands tab
- Firewall Rules to secure the private network and give the guest network internet access:
- Copy/paste the below, then click Save Firewall
iptables -t nat -I POSTROUTING -o `get_wanface` -j SNAT --to `nvram get wan_ipaddr` iptables -I FORWARD -i br1 -m state --state NEW -j ACCEPT iptables -I FORWARD -i br1 -o br0 -m state --state NEW -j DROP
More Firewall Rules to isolate guest and restrict services' access:
- Copy/paste the below, then click Save Firewall
iptables -I FORWARD -i br0 -o br1 -m state --state NEW -j DROP iptables -I INPUT -i br1 -p tcp --dport telnet -j REJECT --reject-with tcp-reset iptables -I INPUT -i br1 -p tcp --dport ssh -j REJECT --reject-with tcp-reset iptables -I INPUT -i br1 -p tcp --dport www -j REJECT --reject-with tcp-reset iptables -I INPUT -i br1 -p tcp --dport https -j REJECT --reject-with tcp-reset
Test the guest network, reboot if not working
Special Notes
Guest VAP Passwords
To prevent unauthorized network access, you must use a different wireless password from your normal Wireless Access Point. Though isolated from the LAN, a Guest Network should have a strong password .
Multi-band radios
To have guest VAP's from each radio on the same subnet, create a bridge for them. Also, multiple interfaces would need there own entries for DNSMasq (and the firewall, if applicable), such as for both wl0.1 and wl1.1.
VAP on an Access Point (AP)
If the router is used as an AP and not a gateway (meaning the WAN and DHCP are disabled, but the same subnet as the primary gateway router), firewall rules are needed for internet access and client access restrictions.
- Net Isolation does not work on a WAP so keep it disabled and to get internet access from the bridge:
- Administration->Commands: copy/paste these lines then click Save Firewall:
iptables -I FORWARD -i wl0.1 -d `nvram get lan_ipaddr`/`nvram get lan_netmask` -m state --state NEW -j REJECT iptables -t nat -I POSTROUTING -o br0 -j SNAT --to `nvram get lan_ipaddr`
- Then reboot the router.
- Maintain the rules' order, and note that the bridge and/or virtual interface may be different
For more details on this, see this post. For more on various firewall rules' impacts, see this post.