How do I change the DNS server on the SMC SMCD3GN router/modem?

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I'm a Senior Advisor
Posts: 1,299

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

Rogers has always had control over the modems, just like the Digital Settop Boxes. The real issue here is that this hardware is also a router/gateway that people use and configure themselves. It's a little sketchy for people to configure their internal network and have Rogers changing the software. 


Now if Rogers could find a way to separate the router functionality and software from the modem side and only update the modem side automagically  and offer the users the choice to upgrade the router portion I think that would be a happy medium. That way Rogers can maintain their side of the network and users could maintain their own side.


Or ideally as almost everyone has posted before offer a vanilla standalone DOCSIS 3 modem.


Or users could turn off the router portion of the SMC and use their own routers.

I Plan to Stick Around
Posts: 69

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?





I disagree strongly with your statement.   Your  earlier post  states that Rogers had directed SMC to disable the DNS manual setting in the router (to keep things standard and easy).  That, in effect, is controlling somebody's home network!  


There is a workaround,  which was mentioned, but the workaround  requires that you modify all computers on the network.   A workaround  does not change the fact that the gateway is being intentionally crippled by SMC/Rogers.   ANY firmware change to the gateway portion of the router is effectively controlling  the customer's side of the equipment and therefore controlling to some extent, his use of the local network.


I do not have an SMC modem, so I do not know what ELSE may be inaccessible to the user,  but if SMC can disable  DNS, then I am sure they can change anything else in firmware,  disable existing features,  enable new features, what ever they want, or should I say whatever Rogers wants.   Without knowing what else may be disabled,  I can't comment on other workarounds that might be required. 


The Kindel example was meant to illustrate that a customer owned product, and purchased content is at the mercy of some other entity  who can do what ever they please,  with or without customer consent.  


Deleting purchased content in the case of the Kindel, (making that content no longer available)   and changing gateway firmware  in the case of Rogers  and suddenly disabling a function that was previously available or causes malfunctions which impair the operation and usefulness of the gateway portion is  are, in my opinion  basically the same kind of tampering.   Is it  fair to state that some of the SMC firmware updates have cause more trouble than they solved?   


Another question comes to mind...  When SMC pushes a firmware update,  I assume that they reboot the unit after the update is complete.   Will this cause the gateway section to reset to factory settings,  losing any changes and customization that the customer may have done,  such as port forwarding,  WP2 or WEB security settings,  keys, SSID broadcast etc.    


My D-Link router reverts to factory settings after a firmware update. Fortunately,  they provide a backup facility in the router to allow you to back up the existing configuration and restore it after an update.   Does the SMC offer this utility as well and is it available to the customer so that he can keep a current backup after making configuration changes?

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Posts: 15

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

I am totally non-plussed with the provisioning arrangements for these SMCD3GN units. There are many unexplained impediments to be aware of - some of which I have not seen reported elsewhere, and some I have seen reported here already.


Where to start? First of all, the device's admin logins are NOT accessible to the user. A customer account is accessible, and the password can be changed, but not the user name. The admin account is accessible via a hidden username/password, but this information is never given by Rogers. With the admin account, almost all of the following shortcomings can be overcome.


While @RogersAndrew states that this has no relation to the Kindle travesty, what he misses is that everytime Rogers pushes a firmware update - your user settings are wiped back to their vulnerable initial settings with no mechanism to save the modem's config file - a standard provisioning mechanism for most other devices. So, in this sense, Rogers is wiping out your data - the gonfig file for YOUR modem service. There is, under the admin functions, a capability to save a modem.cfg file locally or remortely, but the function fails to produce any result using Firefox or Safari on Mac OS X.6.6. What settings get wiped?


First of all, all passwords are reset to defaults. The consequences of this unbelievable security blunder are that anyone can access the admin functions of your modem/router via telnet or web via the default accounts, whose credentials are easily found with Google!


Second, a second wireless network that is inaccessible to the customer is automatically enabled. What the purpose or function of this second, uncontrolled wireless network is, is anybody's guess - it has no useful purpose, and in fact robs spectrum from your primary wireless connection. Again, this can be turned off, but only through the admin account - not accessible to the user account.


Third, the firewall, which ordinarily fails the Shields-Up test at because the firewall responds to anonymous pings - a function that normally can be easily turned off - not not on the SMCD3GN! Again, this requires admin access to turn off response to anonymous "pinging".


Fourth, of course you'll want to change the passwords (and usernames, if you could!) from their defaults, but they too are reset after a firmware update. You can, through the admin section, give the customer account access to all the extended configuration options, but of course you'll lose those settings on reset as well.


Lastly, for now, the DNS settings, which CAN be over-ridden in the admin section, are also lost. I am also have a hard time keeping my Bonjour(zcfg)/AFP-overTCP internal LAN functioning, and have not found the solution yet, but is connected to the DHCP server function in some way.


All these settings are lost and must be reset anytime Rogers forces a firmware update. How often does this happen? I don't know, I've only had this modem for a few days and this is what I have already discovered. My "other" equipment has indeed had firmware updates, once - none have had more than that - why does this modem need so many updates after it's in the field!


It's ridiculous to be paying this much money for what I can only describe as sub-standard equipment, and insulting to be told that "you can use it just as a modem with your own router behind it". Perhaps a more reasonable option would be to offer us, the customers who are supporting this enterprise, a stand-alone modem at a lower price.


Hope this helps those who are questioning this piece of equipment. And I hope Rogers re-thinks the provisioning of this device. I do like it - the speed is great, and I was looking forward to the N-speed bump up from my old G-class setup, and it is noticeably faster for inter-networking, so I would like to be able to use this equipment without having to constantly worry that my network could, at any moment, default back to a bunch of insecure, non-optimal settings - Roger's settings.


Cheers All!



I Plan to Stick Around
Posts: 15

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

More feedback on this SMC3DGN modem/router and its provisioning.


I have discovered that setting the DNS manually via the "admin" account does not stick. Pressing "Apply" seems to show the entries you have made are indeed taken, but leaving the page and returning reveals that the numbers have reverted to their default


This may be related to changing the Private LAN IP of the router to Ever since I made this change - which stuck - I have not been able to click the Apply button without getting an error - The PPTP address must be on the same subnet as the router", or something to that effect. The PPTP range default is You can edit the last segment of the PPTP range - but can not change the second-last segment from 0 to 1 - the segment's field is un-editable.


Perhaps the answer is to revert the private LAN IP back to 192.168.0.x, but I have fourteen clients that I would have to change instead of one change at the source.


Another strange omission is the lack of support for Mac clients. Although it is easy to make a wired or wireless connection to the SMC3DGN, and the router's control panel does not work properly with Safari, Mac OS X's native web client. For example, the checkbox on the "System" page that turns off the router's gateway configuration is not visible in Safari, but is in Firefox. Rogers SUpport Agents take note. Also the configuration screen shown in the manual, which is only available via download for Mac users, is from a very dated version of Mac OS X, 10.3.


Bonjour, or zero-config networking, seems to only partially work. This is leading to problems with file, print and other shared services on the network. I'm still investigating this problem, and have found that it is related to the DHCP server, but have not found the solution yet. For now, most services can be found, but attempts to use the service cause the service to "disappear", e'g. Shared items via Finder windows. The Finder's Go->Connect to Server menu command can be used to enter a URI for the desired service, and this usually works - but not always! I'll post a solution if I find one...


Ironically, this modem/router requires more fiddling and end-user configuration than most, while offering the least-accessible configuration for end-users of any modem/router I have ever seen. What makes it so ironic is that SMC and Rogers are trying to make it easier for average consumers to "plug-n-play" their routers. This modem does indeed, work right out of the box, but the setup is insecure and not amenable to modification. Rogers will find this ups their support calls, negating any advantage to either customer or provider.


From what I've been able to ascertain, SMC is responsible for firmware/script updates - so issues have to pass through Rogers to SMC to be addressed in future firmware updates. Such updattes will have to be pushed out to customers, requiring that Rogers can access your modem and re-boot your router - without notice! This seems to reset passwords to defaults, opening the PRIVATE LAN to anyone with a default password and your PUBLIC IP.


Could someone from Rogers please address some of these concerns here? - I'm sure a lot of users will find your answers interesting, and have other questions about this equipment. Any other user's having the same issues as I am?



I Plan to Stick Around
Posts: 69

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

Many of your points have been stated in previous posts in other threads.  All are well taken by forum members, but the issues raised have not yet penetrated the Rogers armour. 


We have received, on many occasions, a rather standard reply that suggests reconfiguring the unit to modem only.   None of the issues regarding lack of backup for customer config items has ever been addressed.  Questions on the reason for  frequent firmware updates have also been ignored by Rogers.


There have been a few hints that a standalone modem MIGHT be in the works.


Generally speaking,  customers are getting the mushroom treatment from Rogers.   Many, like myself,  will not be "upgrading" until a stand alone option is offered,  and in MY case,  that standalone option will have to prove itself for a minimum of 90 days in service without the abysmal record of false starts and nonsense problems exhibited by the SMC combo unit.

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Posts: 15

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

skutflut, Rogers Personnel:


I have read all the relevant postings here, at DSL Broadband Report and also at SMC's website. The general impression seems to be this is a great modem when it works, but very few people are able to get it to that state - neither customers nor technicians - and that there are better DOCSIS 3.0 solutions out there, including standalone modems.


I think the issue here is that this device is being deployed prematurely. If it is SMC's policy to have each ISP support this device individually, then Rogers should have ensured that; a) the device was ready for market; and b) Rogers was ready to support it. I don't believe either of these conditions are being met, and since it is not SMC's fault or responsibility, we have to rely on Rogers to remedy this situation. I hope that such will be the case, as it does not seem to be SOP at Rogers to let their customers down.


It's been two weeks now since I "upgraded" to Extreme, and I have discovered some errors in my previous analysis, and so would like to clarify some of those points from my previous posting as well a adding a few new comments.


I was, in the end, forced to revert the router's private IP subnet back to the default, and reset fourteen client devices to have the router behave. The problem is that you can only change the DHCP pool or PPTP pool's final digit, causing errors when re-submitting the page, and no further changes will be accepted until that "error" is corrected, i.e. setting the private IP back to the default -


Migrating my existing setup to this new modem/router would have been so much easier IF I could have made that one change without "breaking" anything. This should be addressed to SMC as it is an issue with their interface, but only Rogers can escalate these issues to the manufacturer, and it will probably only be corrected by a firmware or script update - not something that we should have to do multiple times every time an issue arises - hopefully they will deliver ALL fixes in one download, but previous history seems to indicate we should expect more incremental updates.


Now that is working, I at least can use my internal LAN without many problems. I mentioned in a previous post that I thought the DHCP configuration was causing LAN problems, and that was partially correct, but it was a result of the sub-netting I had created. Now that problem has been temporarily resolved, it appears to be a NAT loopback issue, for which I cannot find the appropriate solution. Even using the MSO login, there are areas of the modem's admin that are still "hidden", a brief perusal of the its admin directory verifies this, and the occasional hiccup in the rendering of the modem's web interface demonstrates it  - so it would appear even Rogers' personnel do not have full access to the inner workings of this modem.


I was in error concerning the "REBOOT" function as it turns out. Rebooting DOES retain not only your network configuration, but the precious passwords for both the modem's web admin page and the wireless networks. However, some settings are NOT preserved across reboots. The most obvious one is the re-appearance of the second BSSID network - delete it, reboot, and... it's back! Some other settings do not seem to "stick" across reboots, but I won't go into much more detail here and just say - someone should be looking into this.


I was also in error concerning the "script" saving function - it does appear to save a file. I have not attempted re-loading the subsequent file because I am concerned that the function will not work. The file created appears upon inspection to be binary. I would expect to see an XML, or at least ASCII, document as output, which could be manually edited and re-loaded, but this does not seem to be the case with this equipment. Can anyone at Rogers tell me if this backup can be reloaded - and which parameters are being saved, and which are NOT?


At this point, I have to say I'm fairly happy with the modem's performance, the router's not so much, and I am now beginning to home in on why the wireless' performance on iOS devices is so shabby - at least on my network. Two iPod Touch 3Gs and an iPhone 4 also connect to this modem, and they all show very poor perfomance - ping times to the router are almost random, and streaming media is flat-out impossible.


However, I don't think I'm anything like your average user, and I cannot imagine the frustration and anger of some customers when presented with the realities of this particular device. I hope we see some feedback here, and I look forward to using this device to the fullness of its potential - soon!






I Plan to Stick Around
Posts: 69

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

Thanks for the update DMZ.


As far as I can tell from reading in here, Rogers is not supporting the SMC units.  They seem to have an extra level of access to  the configuration settings,  but from all reports,  SMC is pushing all the firmware updates from whereever it is that they call home. 


After reading through your fairly detailed observations,   my decision to avoid the SMC hardware completely is reinforced.   I'll just wait for a nice vanilla DOCSIS3 modem to be offered,   or if that doesn't happen with Rogers,  do some shopping for another ISP that has less of a "God" complex.

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Posts: 15

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?


Well, one more week and I am glad to report I have this modem and router combo working perfectly now.



Though wired connections have been working pretty well since day one, I haven't had many issues with them - it was the wireless that was giving me the most grief. Desktop machines could never get consistent ping times, DNS lookups were slow, and the router seemed to refresh it's connections by disconnecting clients at random, often several times a day. Maximum speeds incoming were never able to top 2.5 Mbps - from the same server that a desktop machine could transfer at ~10 Mbps.


Even worse, wireless handhelds like iPod Touch and iPhones had pinging times that appeared random - anywhere from 100 msec (never less) to 3–4 seconds, and often just timed out. DNS lookups were even worse. This router/modem combo seemed to bring these devices to a standstill, and I was not able to use either device in any kind of way while connected to it. Mail could not be sent/received, web pages never finished loading - if they started at all - and streaming services were dammed completely.


Well, the solution turned out to be simple, but not obvious. As loaded with Roger's default settings, the DHCP server gives out as the DNS lookup for clients on the LAN. There are TWO places in the admin interface that allow you to change this behaviour. First, in the WAN setup you can chose to assign your own public IP - not advisable -  and beneath that, you can assign your own DNS server. You can select and change just the DNS numbers on this page, and, as it turns out, you should.


I simply assigned the DNS that the modem ultimately connects to as the Primary DNS, and gave it Google's Secondary Public DNS, so and


Changing to the LAN setup page, there is also an option for setting up the DHCP/DNS services - and I believe changing the WAN setting in the WAN setup automatically populates the DHCP server info with those DNS numbers. If not, you can add the same numbers here.


Believe it or not - ALL my ping/DNS/speed issues on the wifi portion of the LAN DISAPPEARED.


I am now getting stellar speeds all around.


While this is great for me, it does not bode well for others as the "Customer" login does not allow access to the WAN settings. However, the DHCP settings can be changed on the LAN/DHCP setup page, and I recommend anybody who is having problems to immediately change this. Changing the DNS on your clients does NOT alleviate this problem - though it should - it doesn't, and this is the only solution I found that is reliable and repeatable.


These settings are retained across he Roger's "resets" which happen at random time intervals, sometimes causing the modem to "reset", other times - not. However, resetting the wireless network ALWAYS results in a second, hidden wireless BSSID being created, and the remote admin option always seems to reset itself to "on" as well.


Also, the wireless network seems to take quite a while to "settle down" after a reset - clients are timed-out on re-connecting, and this step must be repeated over and over until - magic - the router suddenly begins accepting encrypted logins. Then everything is fine, great in fact - until a Rogers reset forces me to re-examine the router settings to see a) what happened to cause a reset, b) what settings have been lost/retained, and if c) the reset is a result of a firmware "push", requiring me to look even deeper to see if it affects my setup.


While I am thrilled to get this thing going, I am not thrilled at the complete lack of support or intelligence on this SMC unit, and I am not happy that it has taken me nearly four weeks to get this thing working properly. What about all the other non-technical users out there? This "upgrade" has my wife looking at me like I'm some kind of fool - "If the damned thing doesn't work, just take it back and get a new one!" was her take on the whole situation. Numerous attempts to explain that their is no "other" modem for this service, that there is nothing "wrong" with this modem, and that it is, theoretically, better than the setup we had before have been falling on deaf, frustrated ears. Rogers support people - you are lucky you have not had to deal with her. She is a long-time Mac user, and is quite use to things "just working", in fact that's why we're mostly Apple at home. Maybe Windows users are used to having all these problems with new equipment, and never finding a solution, but we are NOT happy.






I Plan to Stick Around
Posts: 15

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

p.s. to the above....


Saving the script and reloading it does work - but the scripts are, unfortunately, binary, and so un-modifiable by the user.



I Plan to Stick Around
Posts: 15

Re: How do I change the DNS server on the SMC SMCD3GN router/modem?

A few more days, more problems, no solution yet.


I have not had any further issues with wired clients on the LAN - speeds are great, no DNS issues, and no disconnects since making all the changes I have outlined previously in this thread.


However, wireless LAN clients are still not so good. When connected, they work pretty well. Speed is fine, and again - no DNS issues, but pinging is consistently about 100 msec slower on the WiFi. I can live with that, and the wireless signal is as strong as my Linksys WRT54GS, so I'm not complaining about that. The problem is the random disconnects, which can happen to the entire WiFi LAN, or sometimes, just one client - but it is still happening several times a day.


The router's status display says the wireless is up, and there are no errors reported, and the DHCP client table will often show everything as connected - though refreshing the display will sometimes show clients dropping out, it is not consistent at the best of times. The DHCP client table does not seem 100% accurate most of the time, so it's hard to say what's happening here. When I try to re-connect from a wireless client, the modem will timeout on login several times, but patience and persistence will eventually yield a connection. Rinse and repeat on all wireless systems, pray it doesn't happen again, at least for a few hours.


I have all the wired and wireless computers using DHCP with fixed addresses - I do this because random assignments cause Bonjour services headaches, and I am trying to eliminate that problem. The mobile wireless devices are straight-up DHCP clients as they don't need Bonjour services, and all this seems to be okay.


So, I am left with this one problem - random disconnects - and I have no clue as to why it's happening, and so no solution seems forthcoming. The one thing I did see in a Console message on one of the clients was a message that appeared to come from the router about "MAC AUTH exceeded", which, without any context, is hard to fathom. Does the wireless LAN only allowed a specific number of clients? Why would that number suddenly become "exceeding"-ly large?


If I find an answer to this question, I will post it here - though I know the random disconnect issue is being discussed elsewhere on this site - taken all together my experience as outlined in this thread should help some people with other issues - DNS settings, turning off the "extra" wireless BSSID, setting passwords, etc. I have also enabled Port Triggering, which may solve some people's gaming and videoconferencing problems. I have kids using WoW and XBox without issues - except for the random disconnects - and Skype/iChat seem to be working as well. If I have an issue with any of them, I would enable Port Forwarding, but at the moment this is not an issue.


Again, hoping this helps someone somewhere, I sincerely wish someone from Rogers would at least let us know that these issues are being addressed. Perhaps an across-the-board cross-grade to a "known-good" DOCSIS 3.0 router/modem, or a downgrade to a DOCSIS 3.0 modem-only along with some kind of compensation for the limited functionality of this current piece of... equipment would be in order?


Hang Nine!