Obi202 changing MAC address

[ChrisForumName]

To get my new Obi202 to work with my Virgin router I had to forward the SIP/RTP ports to the Obi.

That means using a reserved LAN IP. However, when I do this I get a strange (to me) thing happen - the MAC address shown on the box shows up for the Obi only some of the time. The rest of the time it uses an other MAC.

It takes a lot of faffing to get the reserved table of addresses to show the one that the device actually uses, since you set it up with one address and it may appear using the other. I always thought a device had one fixed MAC for its lifetime.

I'm not sure if it's a good idea to post MAC addresses here(?) or I would do that so that people can comment better.

Anyone have any idea what's happening?

[drgeoff]

Not an answer to your question but it sounds like you have the OBi on DHCP and asking the router to always assign the same IP address to that MAC address.

Why not set the OBi to a fixed address (outside the router's DHCP pool)? The you don't have to worry about the MAC address.

I can't imagine what misfortune will befall you if world and dog know the MAC address(es) of your OBi.

(I'm not convinced that port forwarding is needed but I won't argue as Virgin routers have a bit of a reputation for all the wrong reasons.)

[ChrisForumName]

Not an answer to your question but it sounds like you have the OBi on DHCP and asking the router to always assign the same IP address to that MAC address.

Why not set the OBi to a fixed address (outside the router's DHCP pool)? The you don't have to worry about the MAC address.

I can't imagine what misfortune will befall you if world and dog know the MAC address(es) of your OBi.

(I'm not convinced that port forwarding is needed but I won't argue as Virgin routers have a bit of a reputation for all the wrong reasons.)

That's a very interesting response.
I'm not sure how I set the Obi to an IP address outside the router's DHCP range but it sounds like a good idea. What you surmised sounds spot on - I set it to always assign DHCP 192.168.0.254

The MAC address stamped on the Obi is: 9CADEF217457
It usually appears in the router as: 9cadefff29e2
Although it has appeared as the "correct" one.

Re port forwarding, I'm new to this stuff and I've been reading my head off for a few days to try to solve these problems, so please bear with me if I don't seem to know some things that many here may regard as "the basics".

The port forwarding seemed to work, but I get some calls where the sound from the caller comes and goes. I wondered if the seemingly narrow range of RTP ports for sipgate (5104-5120) is something to do with it. I followed this to set up the Obi:

http://basichelp.sipgate.co.uk/hc/en-gb/articles/204237391-Obihai-Obitalk

And I forwarded the same ports in the Virgin router. Also changed the SIP listening port to 49160.

[drgeoff]

My supposition is that you haven't fully appreciated that the 202 has a router between its two ethernet jacks.  Each of those has its own MAC address.

Unless you have set the 202 into bridge mode (and you will know if you did that as it is not the default mode) the two jacks are not interchangeable.  You must connect the 'Internet' one to your router to get any of its VoIP functionality to work.  However another default parameter is that the onboard web server (the GUI) is not accessible via that jack - only a PC plugged directly, or on a network plugged, in to the other ethernet jack can access the web server.

Clearly you have at some times been using the local web server GUI as you mention following the Sipgate guide to change some parameters.

The setting System Management, Device Admin, Web Server, AccessFromWAN when ticked will allow you to need to use only the 'Internet' jack.  Connect that to your router and your PC to the router.  Leave the LAN jack unused.

If my supposition is correct, this will solve your double MAC issue. The router will only ever report the MAC address on the 202's Internet jack and you will be able to use DHCP and port forwarding without difficulty.

[ChrisForumName]

Thanks Geoff. You're right that I hadn't appreciated that the 202's router would have its own MAC address. That led me to check something else I didn't realise was pertinent until now - I also bought the WiFi plug piece for the Obi and on checking around the settings, it seems that it's that which has the MAC 9cadefff29e2.

The PC connects to the router via WiFi as well.

I tried to set the ObiWiFi to an IP outside DHCP range...
My DHCP says range is 192.168.0.2 to 254. It uses 1 for the router itself ofc.

So I chose 192.168.1.254 and set that in the Obi web GUI:
ObiWiFi --> WiFi Settings --> Internet Settings.

I also set the Addressing Type to 'Static'.

I left the other entries at defaults, but after it rebooted I noticed that the defaults had changed and Default Gateway and DNSServer1 had changed to 192.168.1.1 and... that didn't work.

So I tried changing them to 192.168.0.1 (leaving the IP Address at 192.168.1.254) but that didn't get detected either - the Obi was not visible to the router and the Obi's phone1/phone2 lights didn't come on..

I'm wondering... are there any limitations on the addresses I can choose?

I've set it back for now. It took some doing, for some reason the Obi wasn't showing up in the router even reverting to the old settings.
While reading around the subject, there seems to be a suggestion that the "professional" way is to reserve static addresses inside the DHCP range anyway.

Perhaps I should quit and see if we get any problems, although we don't get many calls as yet so it's going to be difficult to tell.

[drgeoff]

Pity you did not mention the OBiWiFi earlier. Use that or ethernet, not both.

The brain dead Virgin router appears to default to using the entire range of available addresses for its DHCP pool. Most routers do not do that or let you set the range manually. For example, current BTHomeHubs use 192.168.1.64 to 192.168.1.253 for the pool. The router itself is on 192.168.1.254. So with default settings there are 63 addresses available outside the pool.

You cannot use a '1' instead of a '0' as the third number in the addresses. Read up on sub-nets if you want to know the details. Your router is only 'listening' for things with 192.168.0 as the start of their address.

But if you stick with only either WiFi or ethernet connection of the OBi you should be fine with DHCP on the OBi and a MAC address allocated IP of 192.168.0.254 for it set at the router.