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3 Messages
New Install - Netgear CG3000DCR
I just purchased 5 Static IP's for a home lab and the tech installed the new router a couple of days ago. This is when the trouble began.
The previous config was a Business Class with a Dynamic IP. From that router I patched into 4 port ZyXEL firewall, and then into my switch. All worked fine - no issues.
When the new Netgear router was installed I patched that into the ZyXEL and everything on my LAN was fine, but as you imagine this config doesn't much work when i try to use my Static IP's because to use them I have to remove the ZyXEL since it only does Port Forwarding.
If I remove the ZyXEL and patch the Netgear directly into my switch (like it is suppose to) I'm able to connect from the Internet via the 1to1 NAT (like it is suppsoe to). However, my internal DNS on my LAN fails and my servers and workstations stumble trying to talk to AD. If I disable the DHCP on the router and use my internal DHCP Server it fails hard. I can connect to devices via IP, but services such as ADFS and Exchange use FQDN and not an IP to talk.
Has anyoneelse seen this kind of strange behvior with the Netgear CG3000DCR before?
Accepted Solution
MRMO
New Member
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3 Messages
10 years ago
Hi tmittelstaedt,
You are very close to what happened. The issue was related to IPv6 but it was not my "public" addresses that were the issue, it was my "private" LAN were the issue was.
I was odd that DNS name resolution wasn't working internally, but externally everything was fine and i could communicate via IP just fine. However, things like Exchange and ADFS use FQDN's to communicate.
I was able to determine what the issue was by opening a command prompt andtyping "nslookup dc.domain.com". This revealed that everything was going to Comcast's Public DNS servers.
To resolve this issue I removed the checkmark next to IPv6 on the NIC on my servers/workstations (this does not truely disable IPv6). Next I did a "ipconfig /flushdns" and the server/workstation could find the internal DNS server and then all was well.
In order to truly disable IPv6, you must disable it in the registry. This link (http://social.technet.microsoft.com/wiki/contents/articles/5927.how-to-disable-ipv6-through-group-policy.aspx) will describe which registry key to edit, or you can use Group Policies to hit manu boxes.
While Microsoft does not recommend disabling IPv6, there are times such as this where it becomes needed.
So now that we nowwhat the issue was and how to resolve it, the question remains, "Why would Comcast do such a thing"? Truth be told, I doubt they are doing it on purpose but rather out of ignorance. Fix it guys...
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tmittelstaedt
Problem solver
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326 Messages
10 years ago
A bunch of people are complaining that (unknown to them) their systems are picking up IPv6 info from the Netgears.
Until your fully cognisant of IPv6 and how it functions I would TRY disabling DHCP on the ENTIRE public network and simply statically assign everything that has a public IP address that is plugged into the Netgear. You only have 5 usable public IPs so that shouldn't be much of a burden. There is nothing that any of your clients need from DHCP anyway. Also, go into the Properties of your network adapters that are publically assigned and uncheck IPv6.
If you have one of your publics assigned to the Zytel with a bunch of private number system behind that, that's OK for DHCP. Just keep everything on the public network static IPv4 only and see if that solves the problem.
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MRMO
New Member
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3 Messages
10 years ago
The link above was changed when I posted. So let's try again...
http://social.technet.microsoft.com/wiki/contents/articles/5927.how-to-disable-ipv6-through-group-policy.aspx
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