DNS Service Behind Linksys Router

[Asher 0]

Hi,

 

Using a stand alone DVR (I have tried 2 different brands so far) with DDNS service, the system would not update the new IP each time it changes from the ISP.

 

The DVR is behind a hard wired 8 port Linksys router.

If I update it manually it works fine until the WAN address changes.

 

I was wondering if Linksys has some kind of a bug that blocks this.

 

Thanks in Advance.

[VST_Man 1]

which dns service? what linksys model?

 

if your doing it via the linksys, after you put your settings in and svae it the linksys should respond "update sucessful" in red lettering at the bottom of the screen. If you don't get that.it won't update.

 

also, update your linksys firmware to the latest..............

[Asher 0]

I'll get the model of the router soon, and post...but the dns service is being run by the DVR not the router.

 

The DVRs both have it built in...at other locations they work perfectly fine...it's just that one location.

[Asher 0]

which dns service? what linksys model?

 

if your doing it via the linksys, after you put your settings in and svae it the linksys should respond "update sucessful" in red lettering at the bottom of the screen. If you don't get that.it won't update.

 

also, update your linksys firmware to the latest..............

 

Sorry for the delay...the Linksys Router seems to be model: BEFRS81

 

Thanks

[mitstarion 0]

If there's a router connected to the DVR, I prefer to use the free DDNS service/client of a router instead of the DVR. I encountered some DVR's DDNS client does not update to the right IP or the DVR's client kept on updating resulting to blocking of the service.

[VST_Man 1]

what dns service, are you getting sucessful settings after dns is saved?

[DaveM 0]

My understanding of Dynamic DNS is that a DNS name hosting company will update the IP address that is assigned by your ISP and associate it to your domain name as needed. This is usually when the IP changes, or if you request it to be done.

 

The way this should work is your router requests an IP address from your provider via DHCP. When the lease expires, or when the router is rebooted you might get a new IP address. The router will notice the change, and notify your DDNS provider that it has changed. The DDNS provider passes this information along to the rest of the internet.

 

The problem with using your DVR to set this is that the DVR gets its IP address from the router, not the cable/DSL modem. If you have the DVR connected directly up to your providers modem then there won't be an issue, but that is not usually the case anymore.

 

So if your external IP gets changed nothing changes on your internal 192.168.x.x LAN so the DVR doesn't do an update. Even if it did, it would try and update the IP to the 192.168.x.x IP assigned by your DHCP or the one you programmed into it. DDNS providers know that a 192.168.x.x IP is a non-routable address and most will just ignore that change.

 

Bottom line is you should use the router.

 

I don't see why a "smart" box couldn't go to an outside site to find its real outside IP address, then send that info along. I have not seen one yet, and you would need someone to provide that service. You can go to a site like https://www.grc.com/x/ne.dll?bh0bkyd2 to see what your IP is set as (there are lots of other sites that will give that back to you also).

[ver2go 0]

I don't see why a "smart" box couldn't go to an outside site to find its real outside IP address, then send that info along. I have not seen one yet, and you would need someone to provide that service. You can go to a site like https://www.grc.com/x/ne.dll?bh0bkyd2 to see what your IP is set as (there are lots of other sites that will give that back to you also).

 

There are DDNS clients that will do that for you. DDCLIENT for linux can be configured to detect a WAN address locally. Read it from a Router's status page or use an external web page to detect the IP.

 

I'm not sure if any DVR vendors have done this, but it might be possible to port to a linux based DVR if they provide shell access.

[Asher 0]

My understanding of Dynamic DNS is that a DNS name hosting company will update the IP address that is assigned by your ISP and associate it to your domain name as needed. This is usually when the IP changes, or if you request it to be done.

 

The way this should work is your router requests an IP address from your provider via DHCP. When the lease expires, or when the router is rebooted you might get a new IP address. The router will notice the change, and notify your DDNS provider that it has changed. The DDNS provider passes this information along to the rest of the internet.

 

The problem with using your DVR to set this is that the DVR gets its IP address from the router, not the cable/DSL modem. If you have the DVR connected directly up to your providers modem then there won't be an issue, but that is not usually the case anymore.

 

So if your external IP gets changed nothing changes on your internal 192.168.x.x LAN so the DVR doesn't do an update. Even if it did, it would try and update the IP to the 192.168.x.x IP assigned by your DHCP or the one you programmed into it. DDNS providers know that a 192.168.x.x IP is a non-routable address and most will just ignore that change.

 

 

 

I see your point and it makes a lot of sense, but...these DDNS services are common in modern DVRs and I have used them many times behind routers, and they do work updating the WAN IP every 5 minutes (or whatever interval is set).

 

I can always use the service the router provides, or even use services like no-ip, DynDNS, TZO, etc...and just place their client on a local machine and I'm done. But I'm trying to use the service provided by the DVR and understand why this one location with the Linksys router, would block it or limit it.

[DaveM 0]

In order for the DVR to update the WAN IP, it has to know what it is. Normal DHCP from a Linksys will give you your internal IP, netmask, default gateway and DNS servers.

 

Your right, that if the DVR has some way to determine the WAN IP then I can see how it could do it, otherwise I don't see how, at least not on the boxes I've seen. I'm wondering if the router could have been set to do the DDNS update at the other sites and it just seemed that the DVR was doing it? Or maybe one of the PC's has that client on it. I am looking forward to hearing what your solution turns out to be.

[rory 0]

where the DVR's usually fail to update the IP is when they try to access a server in say china or taiwan from say the US or the Bahamas, does not always connect and hence it fails and at least occasionally you can get an old IP. There are free services with better servers and at least on our side of the globe, which they could use to deal with that though, or even paid services but then the cost of the DVR would be higher.

 

All it needs to do is to connect to a remote server, they grab the IP, update the users data, and send back to the router/dvr that its updated.

[Asher 0]

In order for the DVR to update the WAN IP, it has to know what it is. Normal DHCP from a Linksys will give you your internal IP, netmask, default gateway and DNS servers.

 

Your right, that if the DVR has some way to determine the WAN IP then I can see how it could do it, otherwise I don't see how, at least not on the boxes I've seen. I'm wondering if the router could have been set to do the DDNS update at the other sites and it just seemed that the DVR was doing it? Or maybe one of the PC's has that client on it. I am looking forward to hearing what your solution turns out to be.

 

 

Well...no the routers were not set up to do anything with the ddns, and no dns update clients on any of the computers.

I set up regular routers just so they can share the internet connection, and nothing else.

 

And the DVRs would do the updating, ofcourse once they are setup to do so, with the correct gateway, etc...

 

I'll probably go there and try to setup the router to do it, and see what happens...I'll post back results.

 

Meanwhile if you are interested I have awsome DVR that's very user friendly and you can even choose your own domain with in the DVR i.e. davedotdvrdotnet and that would be the address you connect to for viewing...the DVR does everything on its own you just choose the name, and open a single port on you router and you are done. It even has 2 way audio so you can talk back to the people where the DVR is from your remote location. contact me for more info.

 

Thanks

[Asher 0]

where the DVR's usually fail to update the IP is when they try to access a server in say china or taiwan from say the US or the Bahamas, does not always connect and hence it fails and at least occasionally you can get an old IP. There are free services with better servers and at least on our side of the globe, which they could use to deal with that though, or even paid services but then the cost of the DVR would be higher.

 

All it needs to do is to connect to a remote server, they grab the IP, update the users data, and send back to the router/dvr that its updated.

 

I know what you mean...but these dvrs that I've been using for a long time and they allways work...it's only that one location.

 

Rory, since you are an admin here...something off topic...I have limited access to some forums what do I need to be able to access them? for example running security business forum...

 

Thanks

[DaveM 0]

All it needs to do is to connect to a remote server, they grab the IP, update the users data, and send back to the router/dvr that its updated.

 

Ah ha. It looks like I had it a little wrong. Thanks for the info.

[rory 0]

I know what you mean...but these dvrs that I've been using for a long time and they allways work...it's only that one location.

 

Rory, since you are an admin here...something off topic...I have limited access to some forums what do I need to be able to access them? for example running security business forum...

 

Thanks

 

Hi, i dont handle that side of things. Would need to contact either Thomas, or Larry the admin, and they should be able to get you straight.

 

Rory

[Asher 0]

Ok so I tried another DVR and also installed no-ip client on one of the computers in that location....and they both seem to be working independently...so I'm still not sure what was causing the glitch between the other 2 DVRs and that Linksys.

 

But it's been working fine now for the past week, just using the DDNS / IP Forwarding provided by the DVR.

 

Thanks for all the replys