1 |
On 3/31/22 7:21 AM, William Kenworthy wrote: |
2 |
> Hi, |
3 |
|
4 |
Hi, |
5 |
|
6 |
> I am trying to use a raspberry pi ... to create a routed link |
7 |
> between two access points ... so I can access the monitoring port ... |
8 |
> from homeassistant. |
9 |
|
10 |
I'm distilling this down to a Gentoo system participating in two two |
11 |
LANs, both of which are connected as DHCP clients. -- Correct me if |
12 |
I've distilled too much. -- And you want other systems on either LAN |
13 |
to use this system as a communications path to systems on the opposing LAN. |
14 |
|
15 |
> Both AP's connect ok from the rpi but the routing is wrong - I can |
16 |
> ping in both directions from the rpi, but only sometimes from devices |
17 |
> further hops away - can openrc even do this? |
18 |
|
19 |
This seems like a classic routing issue. To me, it's not even an OpenRC |
20 |
issue in any way other than how to add static routes /after/ the network |
21 |
is brought up via DHCP. |
22 |
|
23 |
> My experimenting so far is hit and miss. Trying to static route |
24 |
> or override the default routes doesn't survive a network glitch, |
25 |
> and half the time doesn't seem to "take" at all. |
26 |
|
27 |
Ya. At a higher level, this can be non-obvious how to do this as it's |
28 |
niche routing configuration. |
29 |
|
30 |
> A working example I could adapt would be great! |
31 |
|
32 |
I don't have an example off hand. -- Seeing as I use static IPs on |
33 |
almost all of my machines, I don't even know if OpenRC supports adding a |
34 |
static route /after/ bringing an interface up with DHCP. |
35 |
|
36 |
I do know that the DHCP protocol supports adding additional options / |
37 |
definitions / parameters (?term?) to specify -- what I've been |
38 |
describing as -- static routes. That way DHCP clients will learn about |
39 |
these additional routes and install them in their local routing table. |
40 |
Though I don't know if you will have the necessary control over /both/ |
41 |
DHCP servers that's needed to do this. |
42 |
|
43 |
Presuming that you don't have control over /both/ DHCP servers (as |
44 |
control over /both/ will be needed), I'm going to fall back and suggest |
45 |
what I call the "Customer Interface Router". |
46 |
|
47 |
Specifically, set up port forwarding on the Pi such that when clients on |
48 |
LAN1 connect to $PORT on the Pi, the traffic is DNATed to the |
49 |
HomeAssistant on LAN2 /and/ the traffic is SNATed to the LAN2 interface |
50 |
on the Pi. Thus every system on each LAN thinks that it's talking to a |
51 |
directly attached system in the same LAN. There is no need for routing |
52 |
in this case. |
53 |
|
54 |
I typically only use the C.I.R. when there are reasons that more proper |
55 |
routing can't be configured. The C.I.R. is an abstraction layer that |
56 |
allows either side to operate almost completely independently of each |
57 |
other, save for IP conflicts between each directly attached LAN. |
58 |
|
59 |
|
60 |
|
61 |
-- |
62 |
Grant. . . . |
63 |
unix || die |