Router: MoFi 4500 4GXeLTE-V2, Sim2

[ColinTaylor]

Now about what I did to cause all this trouble. Both computers were in the "Active Leases" box on MOFI's "DHCP page. So I put the information for localhost1 in the "Static Leases" box. What was strange was that MOFI would automatically put the IP for localhost1 in "Active Leases" (192.168.10.188) in parentheses following the MAC address in the "Static Leases" box. In the IP address entree box in "Static Leases," I put 192.168.10.60. Thus there were conflicting IP addresses for this entry in the "Static Leases" box. Could this have caused the cryptic message when trying to log into MOFI after rebooting it (from the menu)?

Also, now that the dashboard is up again, the entry I made in "Static Leases" is still there (complete with the conflicting IP addresses), but the "Active Leases" box is empty!

You appear to have done everything correctly as far as I can tell. The IP address in parentheses is just the current address, not the desired address.

Bear in mind that after power cycling your router you also need to do the same with your PC to pick up the new lease. In fact a "belt and braces" approach would be to turn off the router and the effected PC. Then power on the router first, wait for it to fully boot and then power on the PC. Hopefully now the MOFI will show the correct information.

If you're still having problems after that perhaps you can post a screen shot.

 

[Ken Morgan]

Before I try this again, here are a few comments/questions.

(1) I deleted the entry I put in "Static Leases" for localhost1. The "Static Leases" box is now empty.

(2) The missing two entries, localhost1 (192.168.10.188) and localhost2 (192.168.10.100), in the "Active Leases" box I mentioned last night are now back. We didn't shut the computers down last night, and there must have been a momentary power outage due to the weather, because this morning both computers had taken the first steps to reboot themselves. When I brought them up, the two entries were back (unchanged) in the "Active Leases" box. I assume this was due to the equivalent of power cycling from the power outage--the power cycling that I should have done last night when I first added the one entry in "Static Leases"!

(3) If I understand you correctly, I should add the information for localhost1 back in "Static Leases" just as I did before--except this time follow it with power cycling: first MOFI and then localhost1. Is this correct?

(4) If that is correct, when I do it, what should appear in "Active Leases" and "Static Leases"? E.g., will the 192.168.10.188 IP now in "Active Leases" be changed to my desired IP of 192.168.10.60?

Note: The "DHCP" page of MOFI right now is again just what it was in the image I uploaded earlier on this thread.

 

[ColinTaylor]

3. Yes, add the static lease and save it. Then turn off localhost1. Then turn off the router. Then turn on the router and wait. Then turn on localhost1.

4. 192.168.10.60 should now appear in both "Active Leases" and "Static Leases".

 

[Ken Morgan]

It worked exactly as you described! Thanks again!

I only did it for localhost1, but localhost2 was on during the whole process. The "Active Leases" box now has localhost1 present with my new IP. However, the entry for localhost2 in "Active Leases" is now missing. My guess is that it is because I did not power cycle localhost2. However, localhost2 still has Internet access. Curious.

The last column in "Active Leases" still shows a "Leasetime remaining" number for localhost1 with its new IP. Will this "Leasetime remaining" number just be ignored, since the IP now is "static"?

However, "It's the midnight, moonlight hour." That's from a rock-n-roll song by the Tremeloes (1967). You remember it? What it means in this context, though, is that it's late and time for bed. Tomorrow I'll go through the same process with localhost2. See you then!

Ken

 

[ColinTaylor]

However, the entry for localhost2 in "Active Leases" is now missing. My guess is that it is because I did not power cycle localhost2. However, localhost2 still has Internet access. Curious.

When you power cycle the router it forgets what devices had asked it for a lease (active leases). So for localhost2 to appear in that list you must make localhost2 ask for a lease again. The simplest way of doing that is to power cycle localhost2.

The last column in "Active Leases" still shows a "Leasetime remaining" number for localhost1 with its new IP. Will this "Leasetime remaining" number just be ignored, since the IP now is "static"?

It's only the IP address number that is "static". The client is still being given that address with an associated lease time. About half way through the lease duration (6 hours), or when the client is rebooted, it will try to renew the lease. The router should then just give it the same thing again.

It looks like you can change the lease time on that page from 12 hours if you want to. But there's really no advantage in doing so.

However, "It's the midnight, moonlight hour." That's from a rock-n-roll song by the Tremeloes (1967). You remember it?

Good stuff. Although I missed it at the time, what with being 5 years old.

 

[Ken Morgan]

Good stuff indeed! The Tremeloes became one of my favorite groups the first time I heard them. But now my age comes out--the first time I heard them was 1967! (I was a sophomore at Northern Illinois University.) The Tremeloes followed with "Silence is Golden," also in 1967--better than the Four Seasons' version.

Ah, enough (wonderful) reminiscing.

I went through the same process for localhost2, and everything worked fine!

But now that ominous line again in post #9. Here is the third problem I'd like to pursue. The computer we've been calling localhost1 is actually a dual boot system. I can boot up either in Windows 7 or CentOS. Of course the room starts to smoke with a foul odor if I stay in Windows too long, but I need to test my Web sites in Internet Explorer because it often codes contrary to standards. Anyway, the question is this: Now that we have everything working perfectly with MOFI and CentOS, will disaster befall us if I try booting up in Windows after we have set up these parameters with a CentOS system? I never had any problem doing this using my LinkSys router. But how do you think MOFI will respond when it has to deal with Windows on one of the computers? Will it mess up anything we (you) accomplished using a CentOS system?

Thanks again, Colin!

 

[ColinTaylor]

Windows should be no problem now that everything is setup correctly on the router. Just make sure the network adapter is setup to use DHCP.

 

[Ken Morgan]

Yes, everything worked as you said. I booted up into Windows and made sure I had the same Local Area Connection windows that you posted. Then I shut the computer off, power cycled MOFI, and brought Windows back up. I opened MOFI's dashboard and looked at the DHCP page. The "Static Leases" window had both computers correctly listed, but "Active Leases" only had localhost1 listed. Nevertheless, localhost2 (which can only run CentOS) still had access to the Internet. I did a restart on localhost1 and booted into CentOS. localhost2 was still missing in "Active Leases," but when I rebooted localhost2, it reappeared. So now everything is back to what it should be.

Is there anything surprising in this?

 

[ColinTaylor]

No surprises. Everything working as expected.

The reason you didn't initially see an active lease for localhost2 is because you rebooted the MOFI. The "Active Leases" list is just a record of what devices have asked the MOFI for a lease. It keeps this list in it's RAM so it gets lost when it is rebooted. This doesn't have any negative effect on the client. The client only needs to communicate with the DHCP server on the MOFI when it (the client) starts up to get its IP address. After it's got its IP address it doesn't need to talk to the DHCP server again until its lease expires.

 

[Ken Morgan]

Well, my three "MOFI problems" have been solved, thanks to you, Colin!

Just two closing questions:

You said you found the manual for the MOFI router I have. I haven't been able to do that. Would you be able to attach a copy to an email and send it to me? SNB has my email (somewhere) from when I joined.

Also, the software for a number of other forums I'm a member of have a way for members to print an entire thread, generally in a "print-friendly" form. I couldn't find a way to do that here. Is there a way?

Thanks again.

Ken

 

[ColinTaylor]

http://mofinetwork.com/files/MOFI4500_4GXeLTE_SIM4_User_Manual.pdf

(P.S. I don't have access to your email as I don't work for SNB )

Good question about printing or exporting the thread. I don't know of a way of doing it (not that I've ever tried).

EDIT: The only thing I can think of for the moment is to use your browser's "print page" option but to "print" it to a PDF file. Rather clunky and it depends on how good your browser is at rendering the page around adverts. It also means each page is a separate PDF. Chrome seems a lot better than IE:

 

[Ken Morgan]

Something appeared on MOFI's DHCP's page!! It's a third entry in the "Active Leases" box:

Hostname: it's just a question mark -- "?"
IP Address: 192.168.10.84 (unknown to me)
MAC-address: 6c:33:a9:74:02:4c (unknown to me)

The ethernet cable from MOFI goes into a Netgear switch. Ethernet cables go from the switch to the computers. Could the mysterious entry be the Netgear switch?

 

[ColinTaylor]

That MAC address is registered to "Magicjack LP". Wiki says:

magicJack is a device that plugs into a USB port on the user's computer (or in the case of magicJack Plus, plugs directly into a router) and has a standard RJ-11 phone jack into which any standard phone can be plugged. This allows the user to make unlimited phone calls to the U.S. and Canada. It is a computer peripheral that, in combination with telephony service from the related YMAX Corporation, provides Internet-based telephone service (VoIP) to the United States and Canada. In 2011 the company introduced magicJack Plus, which no longer requires a computer (but still requires the user to have an Internet service provider).

 

[Ken Morgan]

Yes, magicJack is the third device plugged into the Netgear switch. Where was my brain?

Something else strange has occurred. Unless there is a lightning storm, we never shut the computers down. Also, a directory of localhost1 is always mounted in localhost2. This morning, the mount was no longer on localhost2. When I tried to remount, it wouldn't go through, so I rebooted localhost1. Then the mount worked.

Why was the mount lost, and why couldn't I do the mount again without rebooting localhost1? Could the reason be that "12h" time limit on the IP addresses? Even though the same addresses are reissued, could that remove the mount? If so, then we need somehow to shut that feature of MOFI down so that it never reissues the leases. Would the way to do that be just leaving that item blank instead of "12h"?

 

[ColinTaylor]

I can't think of any reason why a DHCP lease would effect an NFS share. But I've always loathed NFS for it's flakiness . I suppose it's remotely possible that for the fraction of a second it took for the network adapter to renew its lease NFS decided the sky had fallen in and just committed suicide . But if that were true you'd never be able to share directories on both machines at the same time because one or other of them would have to be offline at some point.

You could try looking in the logs (probably /var/log/messages) for the reason in went offline.

If you think it's connected to the lease duration you could try changing the lease time from 12h to 0. I don't know whether the MOFI will accept a value of 0 (or 0h), but quite often a lease time of 0 is interpreted is "infinite". In other words the client never renews the lease, other than at boot time.

 

[Ken Morgan]

I like the idea of turning off the lease time. You made a strong case that "0h" would do it. Do you think there would be any danger in leaving the line blank?

 

[ColinTaylor]

I like the idea of turning off the lease time. You made a strong case that "0h" would do it. Do you think there would be any danger in leaving the line blank?

The MOFI should only allow you to enter acceptable characters (or lack of characters) into that field. The manual doesn't give any clues as to what is acceptable, so try a few things and see what is says.

 

[Ken Morgan]

Okay, I'll try 0 and blank.

Can you believe it? I've thought of another question. Instead of running MOFI's ethernet cable to the Netgear switch, I run it to my (beloved, formerly used, and never giving any trouble) LinkSys router? Then would I not be able to make all the settings that we've discussed in this thread in the LinkSys router (which I've done in pre-MOFI days) instead of MOFI? MOFI would then have nothing to do except pass the signal it receives to LinkSys.

I've been told by the man who installed MOFI on our roof that one should not run one router into another router. But as he himself admitted, he is not a network engineer. What do you think?

 

[ColinTaylor]

You could do that. But you have to decide on the pro's and con's of either setup and what you want to achieve. There's not much point changing a working setup "just because you can" unless there's an advantage to be gained.

You don't say what model Linksys you have (or the Netgear switch) so I can't speculate as to whether it's "better" than the MOFI. One of the most common reasons people install a secondary device is because they're not satisfied with the Wi-Fi coverage of their ISP-provided equipment. Or that equipment is fixed in an inconvenient location. For some people Wi-Fi isn't a concern.

Other people want to use features that aren't available on the ISP equipment, like file sharing, media servers, VPN, parental controls, etc. Or maybe there are problems with the ISP equipment, like an unreliable DHCP server.

If none of these things apply to you then you're just adding another piece of equipment for no purpose other than introducing an additional point of failure.

The main reason people try to avoid using a secondary router is something called "double NAT". This causes problems with online gaming, VOIP and accessing internal servers from the internet (via port forwarding). This is what the network engineer was referring to. If you don't use the above then it's probably of no concern to you. If it does cause a problem you can put the MOFI "IP Pass Through" mode (page 48 in the manual).

So it's really down to you and whether you see an advantage in it.

 

[Ken Morgan]

My LinkSys router is "Wireless-G 2.4 GHz Broadband Router 54 Mbps." I turn the wireless off because I like everything hard-wired. That's how I always used it..

My reason for checking the feasibility of using it as a second router in addition to MOFI is that it would be the router connected by ethernet to the two computers and not MOFI. For many years it was the router I used--a DSL modem or a cable modem was connected to the LinkSys and the LinkSys was then connected to the computers. It's quite simple to use the LinkSys router to achieve the setup that was much more difficult for the MOFI. Of course, we have the MOFI working now the way I want it to work, thanks to you! You're right--logically I should stick with the MOFI by itself.

But there is another reason to continue using the MOFI as the only router. You mentioned that two routers can cause trouble for VOIP. That is the phone system we started using in this new house we bought (just as it's the first time we've ever used a MOFI router!). We're using magicJack for VOIP.

So...I guess it's best to stick with just the MOFI. You're analysis really helped. Thanks so much.