Hi guys, im a beginner on network topics and I somehow can't figure out the solution to my problem 
What I would like to do is the following: Connect my OpenWrt router to an existing router (fiber router that gets the internet signal) via lan. I would like to access the internet in the future via the OpenWrt router that has a VPN client runnig. How do I set this up properly?
Thanks in advance.
That would work with all defaults, just connect OpenWrt's WAN port to your existing network (dhcp).
As @slh stated, this should work in the OpenWrt default configuration. The one thing that might need to be changed is the OpenWrt lan IP address if the existing router uses a subnet that overlaps the default 192.168.1.0/24 network for OpenWrt's lan.
https://openwrt.org/faq/change_lan_ip
If there is an overlap, you could change OpenWrt's lan address to something like 192.168.5.1 and that will fix the issue.
okay it seems to work indeed - great!
The only issue I have is how to connect to OpenWrt Luci since 192.168.1.1 is already taken by my other router
This is how:
So i go to interfaces -> lan -> change ipv4 adress into 192.168.5.1
Thats all I have to do?
Yes, exactly.
okay changed it - however even when im on the OpenWrt Wifi I seem to not be able to connect to 192.168.5.1 -> Does it always needs ethernet connected to my PC?
Did you renew the dhcp lease on your computer?
No - how can I do that?
Turn off WiFi and turn it back on again. Or if Ethernet, unplug it for a few seconds.
I even did a quick restart but nothing has changed: I can only connect to my previous router that has 192.168.1.1 but not to OpenWrt router with 192.168.5.1 (I am connected via Wifi to OpenWrt router)
What ip address does the computer have?
192.168.1.78
You didn't successfully change the IP address of your OpenWrt router.
Did you read the article I linked? It describes the process in specific detail.
I did exactly what was mentioned there: * Choose Apply Unchecked in the dialogue box*/. This will apply the settings without checking if you can access the new IP or not, so double check the IP.
Also using ethernet connection between my OpenWrt router and pc I can connect to Luci via 192.168.5.1 -> However using Wifi it doesnt work
What IP address does your wifi device have? Have you turned off wifi and back on again to force it to renew the lease?
Please connect to your OpenWrt device using ssh and copy the output of the following commands and post it here using the "Preformatted text </> " button:
Remember to redact passwords, MAC addresses and any public IP addresses you may have:
ubus call system board
cat /etc/config/network
cat /etc/config/wireless
cat /etc/config/dhcp
cat /etc/config/firewall
root@OpenWrt:~# ubus call system board
{
"kernel": "5.15.162",
"hostname": "OpenWrt",
"system": "ARMv8 Processor rev 4",
"model": "GL.iNet GL-MT6000",
"board_name": "glinet,gl-mt6000",
"rootfs_type": "squashfs",
"release": {
"distribution": "OpenWrt",
"version": "23.05.4",
"revision": "r24012-d8dd03c46f",
"target": "mediatek/filogic",
"description": "OpenWrt 23.05.4 r24012-d8dd03c46f"
}
}
root@OpenWrt:~# cat /etc/config/network
config interface 'loopback'
option device 'lo'
option proto 'static'
option ipaddr '127.0.0.1'
option netmask '255.0.0.0'
config globals 'globals'
option ula_prefix 'fd8a:54b0:70d0::/48'
config device
option name 'br-lan'
option type 'bridge'
list ports 'lan1'
list ports 'lan2'
list ports 'lan3'
list ports 'lan4'
list ports 'lan5'
config device
option name 'lan1'
option macaddr ''
config device
option name 'lan2'
option macaddr ''
config device
option name 'lan3'
option macaddr ''
config device
option name 'lan4'
option macaddr ''
config device
option name 'lan5'
option macaddr '
config interface 'lan'
option device 'br-lan'
option proto 'static'
option ipaddr '192.168.5.1'
option netmask '255.255.255.0'
option ip6assign '60'
config device
option name 'eth1'
option macaddr ''
config interface 'wan'
option device 'eth1'
option proto 'dhcp'
config interface 'wan6'
option device 'eth1'
option proto 'dhcpv6'
root@OpenWrt:~# cat /etc/config/wireless
config wifi-device 'radio0'
option type 'mac80211'
option path 'platform/soc/18000000.wifi'
option channel '1'
option band '2g'
option htmode 'HE20'
option cell_density '0'
config wifi-iface 'default_radio0'
option device 'radio0'
option network 'lan'
option mode 'ap'
option ssid 'OpenWrt'
option encryption 'psk2'
option key ''
config wifi-device 'radio1'
option type 'mac80211'
option path 'platform/soc/18000000.wifi+1'
option channel '36'
option band '5g'
option htmode 'HE80'
option cell_density '0'
config wifi-iface 'default_radio1'
option device 'radio1'
option network 'lan'
option mode 'ap'
option ssid 'OpenWrt'
option encryption 'psk2'
option key ''
root@OpenWrt:~# cat /etc/config/dhcp
config dnsmasq
option domainneeded '1'
option boguspriv '1'
option filterwin2k '0'
option localise_queries '1'
option rebind_protection '1'
option rebind_localhost '1'
option local '/lan/'
option domain 'lan'
option expandhosts '1'
option nonegcache '0'
option cachesize '1000'
option authoritative '1'
option readethers '1'
option leasefile '/tmp/dhcp.leases'
option resolvfile '/tmp/resolv.conf.d/resolv.conf.auto'
option nonwildcard '1'
option localservice '1'
option ednspacket_max '1232'
option filter_aaaa '0'
option filter_a '0'
config dhcp 'lan'
option interface 'lan'
option start '100'
option limit '150'
option leasetime '12h'
option dhcpv4 'server'
option dhcpv6 'server'
option ra 'server'
list ra_flags 'managed-config'
list ra_flags 'other-config'
config dhcp 'wan'
option interface 'wan'
option ignore '1'
config odhcpd 'odhcpd'
option maindhcp '0'
option leasefile '/tmp/hosts/odhcpd'
option leasetrigger '/usr/sbin/odhcpd-update'
option loglevel '4'
root@OpenWrt:~# cat /etc/config/firewall
config defaults
option syn_flood 1
option input REJECT
option output ACCEPT
option forward REJECT
# Uncomment this line to disable ipv6 rules
# option disable_ipv6 1
config zone
option name lan
list network 'lan'
option input ACCEPT
option output ACCEPT
option forward ACCEPT
config zone
option name wan
list network 'wan'
list network 'wan6'
option input REJECT
option output ACCEPT
option forward REJECT
option masq 1
option mtu_fix 1
config forwarding
option src lan
option dest wan
# We need to accept udp packets on port 68,
# see https://dev.openwrt.org/ticket/4108
config rule
option name Allow-DHCP-Renew
option src wan
option proto udp
option dest_port 68
option target ACCEPT
option family ipv4
# Allow IPv4 ping
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
# Allow DHCPv6 replies
# see https://github.com/openwrt/openwrt/issues/5066
config rule
option name Allow-DHCPv6
option src wan
option proto udp
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
# Allow essential incoming IPv6 ICMP traffic
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
# Allow essential forwarded IPv6 ICMP traffic
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 rule
option name Allow-IPSec-ESP
option src wan
option dest lan
option proto esp
option target ACCEPT
config rule
option name Allow-ISAKMP
option src wan
option dest lan
option dest_port 500
option proto udp
option target ACCEPT
### EXAMPLE CONFIG SECTIONS
# do not allow a specific ip to access wan
#config rule
# option src lan
# option src_ip 192.168.45.2
# option dest wan
# option proto tcp
# option target REJECT
# block a specific mac on wan
#config rule
# option dest wan
# option src_mac
# option target REJECT
# block incoming ICMP traffic on a zone
#config rule
# option src lan
# option proto ICMP
# option target DROP
# port redirect port coming in on wan to lan
#config redirect
# option src wan
# option src_dport 80
# option dest lan
# option dest_ip 192.168.16.235
# option dest_port 80
# option proto tcp
# port redirect of remapped ssh port (22001) on wan
#config redirect
# option src wan
# option src_dport 22001
# option dest lan
# option dest_port 22
# option proto tcp
### FULL CONFIG SECTIONS
#config rule
# option src lan
# option src_ip 192.168.45.2
# option src_mac
# option src_port 80
# option dest wan
# option dest_ip 194.25.2.129
# option dest_port 120
# option proto tcp
# option target REJECT
#config redirect
# option src lan
# option src_ip 192.168.45.2
# option src_mac
# option src_port 1024
# option src_dport 80
# option dest_ip 194.25.2.129
# option dest_port 120
# option proto tcp
Everything looks fine. After you reboot your computer/phone or turn off/on wifi, what IP does that device get?
this one here: 192.168.1.78 -> but it doesnt seem to change after off/on or reboot