Auto-renew DHCP after outage

ohbobva

@e4ch Thanks for the script. Just what I needed. I modified it to log to system.log, which uses the clog system, so the log won't get big...

#!/bin/sh
wan="em5"

currip=$(ifconfig $wan | grep "inet " | cut -d " " -f 2)
if test -z "$currip"; then
	logger `date +%Y%m%d.%H%M%S` "pingtest - Detected empty IP on $wan! Will try again in 120 seconds."
	sleep 120
	currip=$(ifconfig $wan | grep "inet " | cut -d " " -f 2)
	if test -z "$currip"; then
		logger `date +%Y%m%d.%H%M%S` "pingtest - 2nd try: Still empty IP on $wan! Will fix now."
		ifconfig $wan down
		sleep 10
		ifconfig $wan up
		sleep 20
		dhclient $wan
		logger `date +%Y%m%d.%H%M%S` "pingtest - Fixing done!"
	else
		logger `date +%Y%m%d.%H%M%S` "pingtest - 2nd try: $wan has IP $currip; ok"
	fi
else
	logger `date +%Y%m%d.%H%M%S` "pingtest - $wan has IP $currip; ok"
fi

axxxxe

Thank you @e4ch and @ohbobva! I am also on UPC in Switzerland and the script has fixed it for me.

EricE

@ohbobva @e4ch thanks for your scripts! This just hit my parents pfSense install - stupid cable went out (and of course they insist nothing is wrong) and pfSense did not automatically reconnect the WAN. I had my mom manually refresh the WAN interface and it came right back up. How annoying! Hopefully they can permanently fix it now that the root cause appears to be evident; in the meantime hopefully this script will take care of it the next time they flake out and swear nothing is wrong but then it magically starts working right after they complain.

Gertjan

@EricE : see https://forum.netgate.com/topic/148017/dhcp-client-issue

Brian Smit

Thank You for the scripts!!
Are the scripts still needed in the latest version of PFsense or is this bug fixed?

Regards

Brian

EricE

@Brian-Smit

@Brian-Smit said in Auto-renew DHCP after outage:

Thank You for the scripts!!
Are the scripts still needed in the latest version of PFsense or is this bug fixed?

I still needed them for my parents firewall.

Brian Smit

Then i indeed also keep using them. I didn't have any issues anymore with Ziggo

Wirepower

So I tried your script, works well.
Pings and says in log that IP is up. However gateway monitor still says down. Have changed monitor IP to Google and still says down. I would need to renew wan lease in order to get it back up. Keep in mind that when gateway monitor is down, the script can still ping and says it’s ok.

So I’m confused why on status/interface it says up but in gateway monitor it says down.
Is there a script that would automatically release and renew if either gateway monitor shows down or interface?

axxxxe

Can someone tell me if the patch to dhclient is still needed for 2.4.5? I just upgraded to 2.4.5 and am wondering if I now need to include the patch mentioned at the link below, or if the patch is already included in the 2.4.5 I just installed.

https://redmine.pfsense.org/issues/9267

Gertjan

Click on your own link, find the line that says :

Patch to pfSense-dhclient-script was applied on 2.4.5 as well

That was 8 month ago.

axxxxe

Yes, I was uncertain about if this meant it was included in version 2.4.5 or if he was reporting that when he applied the patch to 2.4.5 it worked. I assume from your response it's the former.

Gertjan

@axxxxe said in Auto-renew DHCP after outage:

uncertain

The patch was initially targeted for 2.5.0, but finally back ported to 2.4.5(-p1).
I had to read the patch story twice also ;)

tsmalmbe

Setting timeouts and other options worked well on 2.4.5 but after updating to 2.6.0 my WAN does not survive even the first change in DHCP. It goes down and stays down until I reboot the modem. This really really sucks again.

tsmalmbe

@tsmalmbe I tweaked and poked with the custom values and it sorta works again. That said, the ip changes very rarely (not even weekly) so it is hard do say if this works or not. Seems like something that nevertheless should be easy to fix.

Afflicted4917

@tsmalmbe did you ever solve the problem?

Gertjan

@Afflicted4917

2.4.5 isn't used anymore.
Most of the 2.6.0 is probably upgraded to 2.7.0
Why don't you ?

Can you packet capture the WAN interface, port 67 and 68.
You'll see the DHCP (pfsense as a client) requests for sure.
You'll see also the DHCP server, from your ISP router, or, if you use a bridge device, from an DHCP server located at the ISP site coming back. Do they make it to your pfSense ? If they don't : the uplink connection is bad ? ( ! )

appleredwoodpancakes

I'm not sure if my problem has something to do with the OPs initial problem. But I read the whole thread and I am seeing similar issues in my setup.
Also the hardware and location match. I'm a customer of Magenta who took over UPC as some posters mentioned. I always had these connection problems followed by longer periods where everything worked. I always assumed the ISP hardware to be faulty. That's also the reason why I use Pfsense.

My setup is:

ISP modem (bridge mode)
-> pfsense box (old thinkpad with built in nic for WAN and USB ethernet adapter for LAN) >
-> 2 dumb APs for WiFi

My entire network drops every couple of days. I can't connect via wifi nor via LAN. My devices and Pfsense GUI are not reachable. I can only access Pfsense shell via the PfSense box/thinkpad. I can ping to 8.8.8.8 but no device in my network is pingable (send to error).

Both WAN and LAN gateway are assigned the usual IPs. Usually only a restart of the PfSense box helped. But today I observed something strange.

I didn't want to reboot and replaced the WAN interface with a second USB Lan adapter and reassigned the interface via Pfsense shell. Suddenly the local network was reachable again and I had internet although with a slightly different public IP. Internet was very unstable. Pings resulted in packet losses until it completely died down. But the local network was pingable the whole time.

Searched the logs for hints but I'm too inexperienced. Didn't recognize anything severe though.

After tinkering around I assigned the WAN back to the original NIC. Unexpectedly internet came back with the old public ip.

I know this will happen again but I have no clue why. I eliminated any hardware problems one after another also switched cables and tried a ton of gateway, routing and other settings. Nothing helps.

This setup ran stable for months until I updated to version 2.7. that's when all this started. So I suspect Pfsense to be the problem here. 2.7.1 was worse with daily issues. 2.7.2 stays on 2-3 days. Shortly after the update even 6 days.

I have no idea what to do. Tried many steps in this Reddit post but not everything https://www.reddit.com/r/PFSENSE/comments/n4miga/pfsense_doesnt_recover_if_wan_fails_solutions/

Also flashed a fresh Pfsense without any additional packages to no avail.

After that I can only go the way with a script and reboot. Im my case I have to execute the reboot when I can't ping to my local network.

If anyone has an idea I'm all ears.
Cheers

Gertjan

@appleredwoodpancakes said in Auto-renew DHCP after outage:

I can't ping to my local network

And your LAN uses a USB dongle device ....
You are aware that an USB ethernet should be used for very temporary setups ?
Don't fall for it if it seems to work for a short moment. An NIC draws a lot of current, far more as a classic USB thumb nail drive. The slights movement on the USB contacts will introduce a pwoer loss on the power hungry NIC chips and line drivers, and giess what : you didin't find the very big capacitor to even out the power, because there are non (to small). So the NIC gets a kick in the had after a power glitch, doesn't wake up in a good state.
The OS isn't informed about the power down power up state, as it was to fast, to short.
But the link will be 'bad'.
Ok,this is me showing you what might happen when you use 'usb' ethernet stuff : it's a big messy, uncharted territory.
This type of issues go all away as soon as you remove USB from the equitation.

USB NICs is a typical "even if you can, you shouldn't" thing.

appleredwoodpancakes

Hi @Gertjan
Thank you for your feedback. I read a lot about this USB ethernet topic that it is not a good idea but I never saw a detailed explanation. It makes sense. I never "believed" it because my setup was running so well until now. But I wanted to change the setup anyways so that I only run one LAN cable from the NIC and one cable from the WAN to a managed switch via VLANs. What do you think?

I know I could get me the proper hardware with 2 NICs but I just don't want to give up the ThinkPad. I'm too stubborn for it.

Gertjan

@appleredwoodpancakes said in Auto-renew DHCP after outage:

I never saw a detailed explanation.

Me neither.
But way in the past, when computer stuff was more a 'electric' and 'electronic' thing, a lot has been found out the last 3, 4, 5 decades, power was an issue.
See it like this :
A NIC uses quiet a lot of power : the 2 pairs of ether cable wires uses (tens of) milli amps over the wire, and frequencies used are just phenomenal.
As stated above, the electrical USB contacts are just plain 'bad' and power filtering is hard to do on such a small device. Or, the electrics used needs a real good stable power.
USB can drive 'a lot of power (100+ millli mps)' but they were never designed for this. The power they offer is not enough stabilized, but ok for a charger or a light bulb.
Another (silly) reason : USB NIC are created for one type users ^^ Let's say it like this : not the professional ones. So, what do you think of the quality of the USB NIC driver is ? (a NIC driver is as complex as your best Nvidia GPU driver ) : they probably stopped development as soon as it 'works' for 5 minutes.

To make the she shorter : just don't use them. it's just isn't worth it.
This also some what excludes the usage of a laptop as a router. The laptop still has a usage, though, use it as a dumb console terminal access device for your one and only router : a small devices with 2+ NIC"s build in, and a serial port, or, why, not HDMI+keyboard access.
It will be using even less power also. And you've a rock solid connection.
Yo can start with some 'old PC', remove (disable in BIOS) all stuff that you don't need such as 'sound', inspect the mother board NIC and if it says : "I'm a Realtek" then disable that one also.
Get an Intel based 2 or 4 NIC 1 Gbits network card and you'll be good for the better part of your live.