Order / Timing of Booting Modem and pfsense PC

provels

Maybe it's not needed any more, but I've had this set for a long time in Interfaces / WAN / DHCP Client Configuration:

mer

@provels Nice. That would cover what I see temporarily in my configuration. Of course it assumes the modem is always at 192.168.100.1.

But nice.

provels

@mer I imagine it could depend on the brand of modem, but it's be a fixed IP in the Netgears and Motorolas I've had. Or if the modem even offers DHCP in the first place.

johnpoz

@mer said in Order / Timing of Booting Modem and pfsense PC:

Of course it assumes the modem is always at 192.168.100.1.

That IP is pretty common across the makers of modems, sure it could be something else.. But if you get a lease in the 192.168.100.x, its not like the modem would change its IP from 192.168.100.1 to 192.168.100.Z etc..

I have a arris S33 and that is the management IP, all the previous modems I have had over the years it has always been that 192.168.100.1 IP..

mer

@johnpoz @provels I know that "unstated industry standard" is 192.168.100.1, but I've learned the hard way that assuming may cause problems.
Now if IANA had something stating 192.168.100.1 is the default address for devices like cable modems, I'd accept that as gospel

:)

johnpoz

@mer nobody said its gospel and they all use it.. But clearly you got an IP in the 192.168.,100.x range - what I stated is if your device is in fact using 192.168.100.1 - its not going to change to say 192.168.200.1 out of the blue..

montreel

I see several responses mentioning having the modem leasing IPs. At the risk of exposing an embarrassing gap in knowledge:

If the modem is in bridge mode, I thought that it did not in and of itself "have" any sort of IP address?
I thought it was just a MAC-based "conduit" appliance for the ISP to actually connect to a client/gateway?
If the modem is in bridge mode, does it have any sort of DHCP functioning?
If I have the modem fully rebooted and "online" in bridge mode after a service outage: Why does my pfsense box not boot & bind to the modem? I have to boot a live Linux USB first to get the modem to bind with my igb0 WAN.

I will use the "Reject leases" suggestion. I will try the WAN MAC interfaces "spoof" & input the MAC of the WAN igb0. Hope it helps.

stephenw10

Some modems will run as a dhcp server if the upstream cable fails to sync so that a client can access it for diagnostics. That can happen even if its in bridge mode normally.

It might not in your case but you should be aware it can.

montreel

@stephenw10 thanks

NOCling

And 192.168.100.1 is part of the DOCSIS specification.
That's because all cable modems run with this IP address.