Route all traffic through VPN on Fritzbox guest WLAN

Installing and Using OpenWrt Network and Wireless Configuration
1

Hi,
for my Internet connection I only have access to a FritzBox Guest Network, which blocks a lot of Sites. I have set up my OpenWrt Router to connect to this WLAN as a Client and create my own WLAN network. I now want to route all my traffic to my university vpn, so that i can access all sites. I think I have managed to configure OpenVPN correctly on my router, but i'm not able to configure the firewall to route all traffic through to the vpn.

openvpn config:

config openvpn 'univpn'
	option client '1'
	option dev 'tun'
	option resolv_retry 'infinite'
	option user 'nobody'
	option auth 'SHA512'
	option remote_cert_tls 'server'
	option tls_remote 'vpn.uni-paderborn.de'
	option tun_mtu '1300'
	option persist_tun '1'
	option persist_key '1'
	option pull '1'
	option remote 'vpn.uni-paderborn.de 443'
	option proto 'tcp-client'
	option ca '/etc/luci-uploads/cbid.openvpn.sample_client.ca'
	option cert '/etc/luci-uploads/cbid.openvpn.sample_client.cert'
	option key '/etc/luci-uploads/cbid.openvpn.sample_client.key'
	option enabled '1'
	option verb '3'

network config:

config interface 'loopback'
	option ifname 'lo'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'

config globals 'globals'
	option ula_prefix 'fd1b:9e69:6b2d::/48'

config interface 'lan'
	option ifname 'eth0.1'
	option force_link '1'
	option type 'bridge'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '60'
	option dns '8.8.8.8'

config interface 'wan'
	option ifname 'eth0.2'
	option proto 'dhcp'

config interface 'wan6'
	option ifname 'eth0.2'
	option proto 'dhcpv6'

config switch
	option name 'switch0'
	option reset '1'
	option enable_vlan '1'

config switch_vlan
	option device 'switch0'
	option vlan '1'
	option ports '0t 2 3 4 5'

config switch_vlan
	option device 'switch0'
	option vlan '2'
	option ports '0t 1'

config interface 'wwan'
	option _orig_ifname 'wlan0'
	option _orig_bridge 'false'
	option proto 'dhcp'

config route
	option interface 'wwan'
	option target '0.0.0.0'
	option netmask '0.0.0.0'
	option gateway '192.168.1.1'
	option metric '10'

config interface 'vpn_upb'
	option proto 'none'
	option ifname 'tun0'
	option auto '1'
	option delegate '0'

firewall config:

config defaults
	option syn_flood '1'
	option input 'ACCEPT'
	option output 'ACCEPT'
	option forward 'REJECT'

config zone
	option name 'lan'
	option input 'ACCEPT'
	option output 'ACCEPT'
	option forward 'ACCEPT'
	option network 'lan'

config zone
	option name 'wan'
	option input 'REJECT'
	option output 'ACCEPT'
	option forward 'REJECT'
	option masq '1'
	option mtu_fix '1'
	option network 'wan wan6 wwan'

config rule
	option name 'Allow-DHCP-Renew'
	option src 'wan'
	option proto 'udp'
	option dest_port '68'
	option target 'ACCEPT'
	option family 'ipv4'

config rule
	option name 'Allow-Ping'
	option src 'wan'
	option proto 'icmp'
	option icmp_type 'echo-request'
	option family 'ipv4'
	option target 'ACCEPT'

config rule
	option name 'Allow-IGMP'
	option src 'wan'
	option proto 'igmp'
	option family 'ipv4'
	option target 'ACCEPT'

config rule
	option name 'Allow-DHCPv6'
	option src 'wan'
	option proto 'udp'
	option src_ip 'fe80::/10'
	option src_port '547'
	option dest_ip 'fe80::/10'
	option dest_port '546'
	option family 'ipv6'
	option target 'ACCEPT'

config rule
	option name 'Allow-MLD'
	option src 'wan'
	option proto 'icmp'
	option src_ip 'fe80::/10'
	list icmp_type '130/0'
	list icmp_type '131/0'
	list icmp_type '132/0'
	list icmp_type '143/0'
	option family 'ipv6'
	option target 'ACCEPT'

config rule
	option name 'Allow-ICMPv6-Input'
	option src 'wan'
	option proto 'icmp'
	list icmp_type 'echo-request'
	list icmp_type 'echo-reply'
	list icmp_type 'destination-unreachable'
	list icmp_type 'packet-too-big'
	list icmp_type 'time-exceeded'
	list icmp_type 'bad-header'
	list icmp_type 'unknown-header-type'
	list icmp_type 'router-solicitation'
	list icmp_type 'neighbour-solicitation'
	list icmp_type 'router-advertisement'
	list icmp_type 'neighbour-advertisement'
	option limit '1000/sec'
	option family 'ipv6'
	option target 'ACCEPT'

config rule
	option name 'Allow-ICMPv6-Forward'
	option src 'wan'
	option dest '*'
	option proto 'icmp'
	list icmp_type 'echo-request'
	list icmp_type 'echo-reply'
	list icmp_type 'destination-unreachable'
	list icmp_type 'packet-too-big'
	list icmp_type 'time-exceeded'
	list icmp_type 'bad-header'
	list icmp_type 'unknown-header-type'
	option limit '1000/sec'
	option family 'ipv6'
	option target 'ACCEPT'

config include
	option path '/etc/firewall.user'

config rule
	option src 'wan'
	option dest 'lan'
	option proto 'esp'
	option target 'ACCEPT'

config rule
	option src 'wan'
	option dest 'lan'
	option dest_port '500'
	option proto 'udp'
	option target 'ACCEPT'

config zone
	option name 'vpn_fw'
	option output 'ACCEPT'
	option network 'vpn_upb'
	option masq '1'
	option input 'ACCEPT'
	option forward 'ACCEPT'

config forwarding
	option dest 'wan'
	option src 'lan'

config forwarding
	option dest 'vpn_fw'
	option src 'lan'

Thanks a lot

2

Rather than the firewall you need to configure a static route. You can do this in Luci or config files.

3

Can you give me a hint what the static route has to look like and do i have to deleted the firewall zone?

4

try with
option redirect_gateway 'def1'

this should setup routes to route all traffic over the vpn except traffic to the vpn-server itself.

5

Thank you, that worked.

6

I have noticed that the DNS Server provided by the Guest Wifi is still used. I can change the DNS Server when I'm connected to the VPN, but if the VPN is not connected I have no Internet connection, if I use a different DNS, so I can't connect to the VPN.