Test Lab DHCP & RRAS Woes

Kidge · 19 Oct 2015 at 21:01

Hi,

I'm trying to set up a test lab to practice for an MCSA in Server 2012 R2 and have attempted to set up a RRAS with NAT by following this guide:

http://www.falconitservices.com/support/KB/Lists/Posts/Post.aspx?ID=77

I've then gone on to complete the DHCP part however when trying to connect the clients I just get unidentified network and a 169.254 address.

Any ideas as to why it won't pick up an address from the server?

Caged · 19 Oct 2015 at 21:12

Did you set the DHCP server up?

What happens if you manually assign an IP address in the NAT range?

Kidge · 19 Oct 2015 at 21:19

Yep DHCP server set up on the same machine and I'll test static now

Kidge · 19 Oct 2015 at 21:22

It allows me to set static but I'm unable to ping the server so still no network connection

Kidge · 19 Oct 2015 at 22:40

Ok I thought I'd delete the virtual switches I had created and start again however it failed and then when I finally got rid of the one binded to my hosts physical nic it wouldn't allow the host to connect. I had to uninstall my nic drivers and reboot for the host to get network connectivity however now I'm unable to create virtual switches as it keeps failing

Kidge · 20 Oct 2015 at 09:12

After some Googling it seems that either my nic may be the issue or hyper v will reinstall drivers again tonight

Kidge · 20 Oct 2015 at 17:17

Re-installed NIC drivers - Reinstalled Hyper-V and still no luck. I dont understand why this has just stopped working?

Does any one else have any ideas?

Kidge · 20 Oct 2015 at 19:25

Not a real fix but I ended up re-installing Windows and starting fresh and it is now allowing me to bind my network adapter and create virtual switches.

Hopefully I'll be able to set up RRAS now.

Kidge · 21 Oct 2015 at 23:09

Ok this is starting to annoy me now! I can now create virtual switches again but the clients still aren't picking up an ip address from the dhcp.

I have two switches 1 external for wan and 1 private for the lan and I believe I've set dhcp up correctly as I've followed the above guide I posted.

Has anyone got any ideas as this used to work the only difference I can think of since it last work is that the host machine I'm using has recently been added to my home domain but can't see that affecting it?

Kidge · 22 Oct 2015 at 17:01

After much hair pulling out I've found that the windows firewall on the DHCP is the culprit when i turn it off the clients receive an IP address.

Dont know why this is happening as i deleted all the rules inbound and outbound and only added remote desktop rule which worked in the past so no i'm going to try find the rule i need to add.

Kidge · 22 Oct 2015 at 17:15

Happy man now as I've sorted it. Had to add an inbound rule to allow UDP 67 2535 connections on the server with DHCP role installed and now it's all working.

Can only assume that a security update has been installed since i last tried it as i didnt have to do this in the past.

Scrolling up looks like i'm mental as i'm replying to myself however hopefully this helps someone in the future.

Hellsmk2 · 22 Oct 2015 at 23:35

Kidge said:
i deleted all the rules inbound and outbound and only added remote desktop rule...

I think you just answered your own question. If there's no rule to allow the dhcp ports, then it won't work. For info, UDP ports 67 & 68 are used for DHCP.

As a rule of thumb, never delete the default rules for Windows Firewall. Disable them if you must (though I can't think of a valid reason). The vast majority of businesses will simply disable the firewall via GPO anyhow- it's an unnecessary complication when you're already sat behind a corporate, and hopefully security hardened firewall.