Worth restarting ISP modem even when in pure bridge mode
-
This is just something I learned today and maybe it can be of help to others.
I have a netgate SG-1100 running in my home and I ordered a second (spare) netgate SG-1100 to experiment with and eventually sync with my main unit to keep for emergencies.
When I unboxed the new unit and connected it to my ISP wire I did not get a WAN IP. I did get a WAN IP in lab config. My ISP line is coming from a cable modem/router that I configured as bridge mode. Effectively, it's just a pass through box and I get my WAN IP's from the ISP DHCP server. And it happily services my main unit every time I connect it, it obtains a WAN IP within seconds.
So why wouldn't my new SG-1100 box get an IP address from that same line?
TL;DR
My new SG-1100 did not get a WAN IP address until after I rebooted the ISP modem/router. I never thought this box could be the culprit as it was performing OK with my other SG-1100 box. So there, if you have this issue, it may be worth rebooting your ISP box.Pete
-
@cabledude This is known and common - any time you change the device connected to a cable modem or gateway (modem/router) in bridge mode you would need to power cycle.
This because the mac address of the device connected has changed. If you connected say a 2nd router and you set the mac address to be the same as the device previously connected then the reboot wouldn't be needed to get IP on the 2nd device.
-
@johnpoz thank you for clarifying. I wasn’t aware of that. And particularly, when I replaced my former unifi USG with the first SG-1100 about a year ago, there was no need to power cycle the cable modem at all. At least I didn’t consciously reboot the device, maybe as a precaution.
Fast forward to yesterday, after rebooting the cable modem I can alternate between the two pfSense boxes and both will get their own IP addresses over and over without the need to keep rebooting the cable modem in between.
Well at least this is a topic now for any other beginners like myself that scratch their heads over this issue.
Pete
-
@cabledude said in Worth restarting ISP modem even when in pure bridge mode:
two pfSense boxes and both will get their own IP addresses over and over without the need to keep rebooting the cable modem in between.
Really you get public ip 4.5.6.X with one, and then other one gets 4.5.6.Y? that is a new trick, you sure your not natting at your isp device?
-
@johnpoz said in Worth restarting ISP modem even when in pure bridge mode:
Really you get public ip 4.5.6.X with one, and then other one gets 4.5.6.Y? that is a new trick, you sure your not natting at your isp device?
Not quite.
My main SG-1100 gets 24.b.c.d. It always gets the same 4 octets (reconnected about a dozen times the last few days)
My spare SG-1100 gets 77.p.q.r
Not any of the 8 octets in the above are the same.After resetting the spare to factory:
My spare SG-1100 gets 80.x.y.z
My UniFi USG got 62.m.n.o
Then later it got 77.251.e.fSo you might understand that when I see that my main SG-1100 obtains an IP address and then when I switch to UniFi USG that gets an IP address too, I assume the ISP modem/router is working well, and the IP side DHCP server too.
Does this behaviour surprise you?
-
@cabledude said in Worth restarting ISP modem even when in pure bridge mode:
Does this behaviour surprise you?
Well it does that you can swap them and get IP from the isp.. What if you connect something different.. Or change the mac of one of the devices to be different without rebooting the modem.
Its possible they can keep more than 1 mac that has been "paired" for lack of a better word.. But let say you take some pc different mac that has never been directly connected to your modem before and just swap that in without a power cycle of the modem. Does it get an IP?
-
@johnpoz I connected an old (ancient, roman era) fritzbox and it did not get an IP. However I didn't yet check its DHCP settings so this doesn't count as anything definitive yet.
I'm hesitant to connect any other (non firewall) device exposed directly to the internet.
However I'm still learning things about networking which is (for me) the absolute bonus. Last week my 15yr old daughter came to me and asked me if she and I could do a philosophy assignment together which taught me that love (or in this case love for wisdom) can be more about the journey than the destination. In other words, learning new things and still not knowing everything can be most enjoyable.
-
@cabledude said in Worth restarting ISP modem even when in pure bridge mode:
learning new things and still not knowing everything can be most enjoyable
Well stated - and agree 100% If I don't learn something new even in networking every day its a bad day..
Not saying you need to "leave" it connected, just long enough to see if it gets an IP and can talk to the internet - like 1 minute tops worth of testing..
-
@johnpoz said in Worth restarting ISP modem even when in pure bridge mode:
Not saying you need to "leave" it connected, just long enough to see if it gets an IP and can talk to the internet - like 1 minute tops worth of testing..
Okay I dug up an old retired 2008 MacBook and connected it directly to the ISP cable (with sweaty hands). The macbook immediately received an IP address 80.xx.xxx.xx6. I unplugged the cable and inserted it again, same IP. The machine was lagging / unresponsive at times but that seems normal. I went to safari and typed apple.com and that web site came up after about 15 seconds.
I could try the old fritzbox again but by now it is clear that the ISP modem/router need not be rebooted every time I connect a new device. This macboom it had never seen in its life.
Still the spare SG-1100 would not work unless I rebooted the ISP modem. Peculiar...
Pete
-
@cabledude Edit : another possibility is that the ISP modem router was stuck somehow and rebooting it once brought it back altogether .
-
J jimp moved this topic from Problems Installing or Upgrading pfSense Software on
