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RVS4000 > Set ROUTER to use custom dns?

aaron.martinas
Level 1
Level 1

here's my situation:

my ISP assigns me a dynamic ip address. this is pretty standard. along with my IP, i receive my DNS settings as well. this is completely normal. i totally understand this.

however, i wish to use CUSTOM DNS. in windows, i can accomplish this very easily. in the "network connections" window, i select the properties of my network adapter. if i change the properties of the TCP/IP protocol, i get the dialog that is present in the "windows.png" file attached to this post. here, i am able to ensure that my computer receives the dynamic IP, but i then overwrite the DNS and use my own.

simple.

i want to do this on my RVS4000 router. i want to set up custom dns as the subject implies.

before you start screaming about the "Server Settings (DHCP)" section in the "lan" tab under "setup", this is NOT correct. why, you say? because when you set this up this way, the DNS information is forwarded to the DHCP clients. this does NOT change the ROUTER'S dns. i want to know how to change the ROUTER'S dns.

again, using the windows scenario i described above, i should be able to tell the ROUTER to use a custom DNS. BUT WAIT! before you scream "use the Internet Connection Type" in "wan" under "setup", consider the fact that i have a commercial ISP and that i HAVE TO USE DHCP to get an IP and connect to the internet. and belive me, i've already tried workarounds... i set my router in DHCP, got an address, then without rebooting the ISP's modem, i changed my "internet connection type" to "static ip", using the information i got when i was in dynamic mode. THIS DOESNT WORK. PERIOD. THE INTERNET DOES NOT WORK, DESPITE THINKING IT SHOULD. im sure the ISP is forcing something down my throat. also, even if this DID work, this would be COUNTER-INTUITIVE. why? because if my ip were reallocated, i would lose network connection. by design, i should use DHCP, and i shouldn't try to circumvent it.

so now that i've clearly explained the issue and all the hurdles, how can i set up custom DNS on my router while in DHCP mode (just like windows has APTLY SHOWN IS EASILY POSSIBLE SINCE PROBABLY 1995)???

another question you may be asking yourselves-- why not just let my clients get the custom DNS and be happy? because i have some internal network names that i still want to have access to. if the clients have the custom dns shot directly to them, they will never be able to resolve those internal names. if i can just tell my stupid router to use custom DNS, the clients still use the router as their DNS, and when the router receives the requests, it can then determine if DNS request is internal and send it to that nic, or if it needs to go outside.

I'd REALLY appreciate CISCO response on this

17 Replies 17

alegalle wrote:
You provided this link http://support.microsoft.com/kb/172218 but fail to point out a very important piece; "Unless you change the order in which lookups occur."

again, you're suggesting having to make changes to computers. also, you forget that when i dont use custom DNS, everything works without making this change. so why should i need to make a change at the comptuers just becasue the router is flawed?

alegalle wrote:

Also, since you read that MS article you also understand that DNS has nothing to do with NetBIOS. The problem is not on the router nor on your network. The problem is that NetBIOS is deprecated and systems like XP and above much rather use DNS.

no, the problem is that when i dont use custom DNS, my netbios lookups work perfectly. "depreciated" or not. when i use custom DNS, the router becomes it's own obstacle in netbios lookups.

alegalle wrote:

Well since you can specify a primary and a secondary DNS server, why don't you specify the router as DNS 1 and OpenDNS as DNS 2. Would this not solve your problem?

WHAT? im sorry, do you even work for cisco? if i made my router DNS1, then all the clients would get their DNS requests forwarded to my ISP dns (since my stupid router cant use custom DNS), defeating the purpose of custom DNS!!! ARE YOU JOKING ME?! DID YOU EVEN READ THAT BEFORE YOU WROTE IT?!?!?!

alegalle wrote:

Current systems do not make a lot of concessions for NetBIOS so having a hard time with this nowadays is not surprising; and I do understand your frustration. Just think, all of this could have been avoided if you would have changed the order of Name Resolution on your clients.

youre joking me, right? when i dont use custom DNS, netbios works FINE. it isnt a "hard time". you dont understand my frustration, judging by your lack of understanding of this situation. just think, all this could be avoided if i could just specify custom DNS for my ROUTER just like i can do in windows. just think, i would only have to make ONE CHANGE to ONE DEVICE and EVERY DEVICE that used netbios would have the same results.

lets do some math. 1 change to one device is LESS THAN 2 changes to 2 devices, 3 changes to 3 devices, etc etc etc with all your host file and netbios resolution order mess.

alegalle wrote:

Your example of XP I must comment on; XP is not a router, and you can do exactly as you stated; however, in its default state it is not a router nor can it hand out DHCP addressing.

clearly, this was not what i was getting at. i was getting at the fact that in NETWORKING, it is possible to have DHCP allocate you an IP and DNS information and lease information, but to then NEED to set custom DNS. and it's not theory. but for some reason, cisco thinks it should remain theory and subject of "discussion". oh, and apparently it's ONLY an "enterprise class" feature.

alegalle wrote:

Then you finish (along the way insulting others) stating how "" it is that your RVS does not support this feature. That would be the same as going back to my Honda dealer and completely insult, yell and show them how wrong they are for not telling me why my 2009 Honda Civic LX does not have a 6 speed transmission, when the red Civic SI right in front of them does. "Can't you not put that transmission in my LX, Does Honda really know what they are doing......??"

first of all, "asinine" isn't a swear word. i know it scares you, but it isn't. second of all, the your analogy is terrible, and it's reaching. i want a feature of networking that fits directly into the scope of networking. nothing more, nothing less. technically, netbios isnt the issue here. it's just what made me come calling. the fact that i cant set my own custom DNS on the ROUTER = why ill NEVER buy another linksys or cisco product again ever.

Sorry. But what you write gets more and more confusing. You want custom DNS on the router itself because the router would do something different with this custom DNS then your Windows DNS client would do if it used the custom DNS directly?? This does not make much sense to me.

1. You wrote that it works fine when you don't use custom DNS. So why do you want to use custom dns if it works without it?

2. you wrote before this in case the router resolves without custom dns:

"dns is attempted. the router for WHATEVER REASON does not forward the request out to the ISP's dns server. DNS FAILS"

and then this is how the windows client would resolve through an external custom dns server:

"dns is attempted. THE CLIENT SENDS THE REQUEST OUT TO THE DNS SERVER, AND THE SERVER IS LIKE WTF IS THIS!? either the server responds "are you stupid?" and resolution fails, or the server responds "yea, here's a 'portal' IP address". which is INCORRECT ANYWAY!"

Now, what on earth should change if you set custom dns on the router? The router would use the same custom dns server and would deliver the same answer to your client. The DNS server on the RVS is a simple DNS forwarder. It does nothting but forwarding DNS requests back and forth. That's all.

If the custom DNS server you want to use returns a "portal IP address" for any unresolved hostname then it will do so regardless whether you point your Windows DNS resolver directly to that custom DNS or whether you pointed your RVS to that custom DNS. It will always return the same.

If the router really returned something different from a DNS server then then Windows DNS resolver would do from the same DNS server then that would be at best a bug in the RVS because it should not fail then (unlike what you write above and what you want).

So reading your initial post again it seems as if you want to use a custom DNS server which does resolve non-existing hostnames to some portal IP address. I think that's your real problem. And that problem won't go away even if you could set a custom DNS on your router. As I said: the DNS server on the router is a forwarder. It does nothing else but forwarding. If won't miracously fail some DNS requests if the custom DNS server delivers something.

aaron.martinas
Level 1
Level 1

CISCO apparently think's that the ability to set custom DNS on the router is not worthy of business class. It's a "known product limitation". But i assure you, there's no good reason for this limitation.