When internet goes down network goes down

[foxint]

Hi. I have been using OPNsense for a few months. Please accept my apologies now.

I am total novice and did a basic setup using a You Tube video. I have nothing fancy, I used OPNSense because my modem broke and I live in the Aussie Outback and no one sells modems, so I made one from an old HP PC. (They filmed the latest Mad Max film here and yes there is nothing here. It is a mining town with rock and desert).

I have a LAN comprising of 5 PC's all with static IP addresses. When I am using the internet and it stops and pauses – that it does all the time, I cannot access any of my PCs on the LAN. I use programmes that must connect to the internet to function, and I access this via my workstation on another PC on the network. (This arrangement is the preferred arrangement from the software vendor – MYOB. It is a real princess of a programme and as such I had to buy a completely new PC as it does not like sharing).

I searched - when internet goes down network goes down. I could not find anything. I probably asked the wrong question. Please do not shoot me I am 66years old and need a young bloke to help.

Anyone????

Dan

[Patrick M. Hausen]

How is your internal network set up? Do you have a switch? What do you mean by "Internet goes down"? Just the external connection and you can still ping OPNsense or is OPNsense crashing (possibly) and unreachable?

[blubern]

I have the same behavior - with no internet i can't reach any other device internally.
But from the device i can reach opnsense.
what should i monitor to figure out what is the problem?

[Patrick M. Hausen]

First describe how your devices and OPNsense are connected to each other.

[blubern]

=> My OPNsense has three interfaces
1. connected to wan (pppoe)
2. connected to a NAS
3. connected to a switch - on the switch are all devices connected inclusive the wlan access points.

when wan goes down i cant reach pc1 over lan from pc2
and when wan comes back it need about 2 min that dns will start to work again

[Patrick M. Hausen]

pc1 should be able to communicate with pc2 via the switch. That traffic SHOULD not pass through OPßnsense.

Please post your DHCP settings for the interface connected to the switch (LAN?).

[blubern]

I switched today to the Kea DHCP

Could the issue be that there are some VLANs?
PC1 and PC2 are in different VLANs

[pfry]

[...]
Could the issue be that there are some VLANs?
PC1 and PC2 are in different VLANs

Possibly. VLANs offer optional layer 2 isolation (it depends on your switch configuration). There are endless potential issues with VLAN configs - you'll have to describe your topology in much more detail for folks here to help out. On OPNsense, perhaps copy the Interfaces -> Overview text and edit it appropriately (or simply capture and post it - up to you) as a start. Don't forget switch config/topology details too.

Still, I would expect OPNsense to route whether the PPPoE session is active or not. Your config (and foxint's) should be interesting. Perhaps another VLAN tagged + untagged mix effect I haven't thought of?

[Edit:typos]

[foxint]

Hi Patrick et al.

Nice to have a friendly post.

Connection: Internet modem to OPNsense box – OPN to switch – all PC's to switch via ethernet.

Internet goes down – I cannot get anything from the internet. The internet indicator (Win 10) on the task bar says no internet.

When I take OPN box out of the system the network operates. When it is in the system and the internet goes down, I cannot access my PC's on the network.

VLAN – not sure what this is and I do not think I have a VLAN.

Dan
 (PS I did not get a notification of the replies????)

[cookiemonster]

@blubern - best if you open your own thread so the question and answers don't get all mixed up. Please.

@foxint - Please tell what are your DNS settings, so to rule them out.
a) Systems | Settings | General.
b) Unbound or dnsmasq - which do you have enabled, share the settings.
c) On your LAN interface settings. Share those too please.

[Patrick M. Hausen]

Yep - we definitely have two unrelated problems here. With VLANs in place, of course local communication breaks whenever OPNsense breaks for some reason.

Without VLANs and an unmanaged or simple switch, local communication should not be affected by OPNsense failing. Unless e.g. DHCP settings (netmask!) are wrong.

@foxint please also show your DHCP settings.
@pfry please open a separate thread.

[foxint]

Hi Guys – Thank you. I was just doing some testing without the internet. The OPN box and the network seem to work whether I have the OPN Box connected or not.

Can you give me instructions how to find the DNS and DHCP and on what device.

Thanks

Dan

[cookiemonster]

> Can you give me instructions how to find the DNS and DHCP and on what device.
My post #9. Those are the pages to navigate on your OPN machine's UI to get to them.

[Patrick M. Hausen]

Hi Guys – Thank you. I was just doing some testing without the internet. The OPN box and the network seem to work whether I have the OPN Box connected or not.

So the problem is solved? That means we would probably not need to investigate your DHCP settings. I just suspected you might have got the netmask wrong which would explain why PCs cannot talk to each other if OPNsense is down.

Can you give me instructions how to find the DNS and DHCP and on what device.

See @cookiemonster's post - the settings you made on OPNsense, of course.

[blubern]

Hi,

it looks like with the change to Kea the problem is gone!

@foxint sorry that i hijacked your thread
@all thanks for your help and support!