Difference between revisions of "Openwrt"

Revision as of 23:06, 7 November 2020

Recommended Router

Current:

high traffic: x86 PC

low traffic: something with the following:

* uboot bootloader
* doesn't require multiple hoops to install (i.e. no 'two different' serial speeds on the same UART. Friggin' ubiquiti...)
* promotes FOSS and is ok with LEDE/openwrt

Still evaluating them, but it looks like gl.inet is the way to go.

OLD:

https://openwrt.org/toh/mikrotik/rb2011

I used to use these as they are rack mount, but the bootloader is proprietary and i had two of them brick themselves for no reason during the 2nd sysupgrade.

High-end companies can look at https://www.opencompute.org/products

Recommended wireless AP

Open mesh in Oregon was good. But they were bought out. They are now doomed. China has gl.inet which is basically the same as open mesh, although they specialize in small travel routers. Only buy wifi APs that support openwrt.

Tips

port forwarding

Port forwarding is two steps:

redirect port from outside to internal (NAT)
allow access from outside to inside via this port (firewall)

Contents of /etc/config/firewall

config redirect
        option name 'PassthroughformyServer'
        option src 'wan'
        option proto 'tcp'
        option src_dport '80'
        option dest_ip '192.168.1.100'
        option dest_port '80'
        option target 'DNAT'
        option dest 'lan'

config rule
        option src 'wan'
        option proto 'tcp'
        option dest_port '80'
        option target 'ACCEPT'

Note: Proto can be 'tcp' OR 'tcpudp' OR 'udp'

reserved ip / static lease

Contents of /etc/config/dhcp

config host
        option ip 192.168.1.122
        option mac c2:44:32:18:cd:ab
        option name reservedipcomputer

ref: https://openwrt.org/docs/guide-user/base-system/dhcp_configuration#static_leases

I tried to add this to the wiki, but someone (https://openwrt.org/docs/guide-user/base-system/dhcp_configuration?rev=1596434574) decided to replace my simple solution with an obfuscated one that requires uci commands. So instead, it will remain here. EDIT: I added it back. See how long that lasts...

openvpn

opkg install openvpn-openssl

Contents of /etc/config/openvpn

 config openvpn 'custom_config'
        option config '/etc/openvpn/myconfigfile.ovpn'

And your .ovpn in /etc/openvpn/.

aliases

Put in /etc/profile. e.g.

export TERM=xterm
alias vpnme= 'openvpn --config /etc/openvpn/myconfigfile.ovpn & ./script.sh &'

mwan3

Mwan3 can be tricky. The wiki lacks a quick start*. The following files get edited:

/etc/config/network
/etc/config/mwan3
/etc/config/firewall

Tips Page: Mwan3_On_Openwrt

If you add a new WAN interface, (e.g. wanb or wan2) you must add wanb to the existing wan firewall zone for outgoing comms. How this is handled differs from 17 to 19.*2

Balanced policies can have issues with connections jumping from one wan to another.

* the current mwan3 page is a lengthy multi-page behemoth (which has grown over time) that expects no less of you than to understand all functional and architectural details of how the failover works. It's a lot for someone that just wants to setup backup internet. But mwan3 can and does work.

2 ctrl-f for firewall comes up with half a dozen mentions of firewall masking (something done automatically) and one easily missable note, for GUI setup only, about adding the new wan2 to the firewall zone. An absolutely required step.

iptables vs fw3

In the firewall:

iptables -L

will list current rules, but the iptables rule generator is fw3.

fw3 print

Will display iptables commands that make up the firewall. fw3 script is described in firewall pages on official wiki. Please review that.

less with / search

The stock 'less' command does not include '/' search.

opkg install less

To get forward slash search https://dev.archive.openwrt.org/ticket/7132

remove poweroff command

cd /sbin/
rm ./poweroff

Now to power off, you must type

busybox poweroff

This will keep you from accidentally shutting down a router.

misc

start wifi

wifi up  
wifi status

Logging

display (RAM based) logs (note that this is not in /var/log/messages...)

logread

https://openwrt.org/docs/guide-user/perf_and_log/start e.g. https://openwrt.org/docs/guide-user/perf_and_log/statistic.custom and https://openwrt.org/docs/guide-user/perf_and_log/log.messages

various links i found interesting

https://openwrt.org/docs/guide-user/network/traffic-shaping/sqm - speed test, and traffic shaping to speed up a 'slow' network. protip: use x86 instead of arm if openwrt is slow.

https://openwrt.org/docs/guide-user/services/nas/netatalk_configuration - apple time machine backup server

https://openwrt.org/docs/guide-user/network/wan/multiwan/mwan3 - failover for wan. i have used this before, and it worked well.

https://openwrt.org/tag/faq - FAQs

https://openwrt.org/docs/techref/flash.layout - Partitions on ~~HDD~~ flash. And overlay fs.

https://openwrt.org/docs/techref/start - Technical Reference. Has some informative dives into various aspects of low power routers. As an example see this link on flash: https://openwrt.org/docs/techref/flash IME, flash is built in obsolescence. usb drives, sd cards, and onboard flash tend to last much less than advertised. not recommended. SD and SSDs are a trap. from this: even 'reading' flash can cause bad blocks. that's right, even reading. therefore flash is guaranteed to fail. tech companies love it.