[SBS 2011] Slow DHCP
I have a SBS 2011, this is also the DHCP server for us.
I have problem with some PC's (most Windows 7). It takes a long time to start Windows and sometimes is the pc also slow by working. When the PC starts: 'Please wait' stuck for a long time. I think it is a DHCP / DNS problem. Can someone help me?
SETTINGS:
I have the following dhcp scope:
Start IP address: 172.16.0.1
End IP address: 172.16.3.254
Lease duration is limited to: 2 days
Enable DNS dynamic updates is turned of
Network Access Protection is disabled for this scope
On the tab 'Advanced': Assign IP addresses dynamically to clients of: DHCP
Address Pool: 172.16.0.1 - 172.16.3.254 (Address range for distribution)
172.16.0.20 - 172.16.0.60, 172.0.61 - 172.16.0.75, 172.16.0.200 - 172.16.0.220, 172.16.0.1 - 172.16.0.12 (IP addresses excluded from distribution)
The following reservations: 172.16.0191, 172.16.0.114, 172.16.0.91, 172.16.0.88
Scope options:
003 Router 172.16.0.1
006 DNS Servers 172.16.0.200 (SBS Server)
015 DNS Domain Name (Our domain.local)
044 WINS/NBNS Servers 172.16.0.200
046 WINS/NBT Node Type 0x8
IPV6 is also enabled in DHCP (00023 DNS Recursive Name Server and 00024 Domain Search List)
I have the following DNS settings on the SBS 2011 server:
Listen on: Only the following IP adresses (ipv6 address & 172.16.0.200 (SBS SERVER))
Forwarders: 8.8.4.4 (google) and 208.67.220.220 (opendns)
Sorry for my bad english...
I have problem with some PC's (most Windows 7). It takes a long time to start Windows and sometimes is the pc also slow by working. When the PC starts: 'Please wait' stuck for a long time. I think it is a DHCP / DNS problem. Can someone help me?
SETTINGS:
I have the following dhcp scope:
Start IP address: 172.16.0.1
End IP address: 172.16.3.254
Lease duration is limited to: 2 days
Enable DNS dynamic updates is turned of
Network Access Protection is disabled for this scope
On the tab 'Advanced': Assign IP addresses dynamically to clients of: DHCP
Address Pool: 172.16.0.1 - 172.16.3.254 (Address range for distribution)
172.16.0.20 - 172.16.0.60, 172.0.61 - 172.16.0.75, 172.16.0.200 - 172.16.0.220, 172.16.0.1 - 172.16.0.12 (IP addresses excluded from distribution)
The following reservations: 172.16.0191, 172.16.0.114, 172.16.0.91, 172.16.0.88
Scope options:
003 Router 172.16.0.1
006 DNS Servers 172.16.0.200 (SBS Server)
015 DNS Domain Name (Our domain.local)
044 WINS/NBNS Servers 172.16.0.200
046 WINS/NBT Node Type 0x8
IPV6 is also enabled in DHCP (00023 DNS Recursive Name Server and 00024 Domain Search List)
I have the following DNS settings on the SBS 2011 server:
Listen on: Only the following IP adresses (ipv6 address & 172.16.0.200 (SBS SERVER))
Forwarders: 8.8.4.4 (google) and 208.67.220.220 (opendns)
Sorry for my bad english...
Elwin3
ok to confirm it is the DHCP causing the problem assign a PC a static IP address and reboot it. Is it still slow then?
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ASKER
Thanks for all the answers!
1. I'll remove the WINS/NBNS options ASAP.
2. The scope is a bit to much, but 0.1 - 0.254 is not enough. We have a lot of people with multiple devices.
3. I want to try to remove the forwarders and I will check all the DNS settings on the server and clients. I remember I need that forwarders for faster Internet on the clients. You think that's not necessarily?
Many Thanks!!
1. I'll remove the WINS/NBNS options ASAP.
2. The scope is a bit to much, but 0.1 - 0.254 is not enough. We have a lot of people with multiple devices.
3. I want to try to remove the forwarders and I will check all the DNS settings on the server and clients. I remember I need that forwarders for faster Internet on the clients. You think that's not necessarily?
Many Thanks!!
You have this in the SBS topic area. SBS is limited to 75 users, are you sure you have more than 254 devices?
Also SBS 2008/2011 does not support a non 255.255.255.0 subnet mask (.x.1 to x.254 subnet), so I suspect if you run the network wizards and/or BPA they will fail. "The NIC must use a private IP address with a 255.255.255.0 subnet mask. " see:
http://blogs.technet.com/b/sbs/archive/2008/09/16/sbs-2008-supported-networking-topology.aspx
Fowarders are not a problem, but the forwarders you have choosen could be. Some respond faster than others. I think Hypercat was suggesting try removing them and use root hints (SBS default) as a test.
Also SBS 2008/2011 does not support a non 255.255.255.0 subnet mask (.x.1 to x.254 subnet), so I suspect if you run the network wizards and/or BPA they will fail. "The NIC must use a private IP address with a 255.255.255.0 subnet mask. " see:
http://blogs.technet.com/b/sbs/archive/2008/09/16/sbs-2008-supported-networking-topology.aspx
Fowarders are not a problem, but the forwarders you have choosen could be. Some respond faster than others. I think Hypercat was suggesting try removing them and use root hints (SBS default) as a test.
ASKER
I removed the forwarders and it looks like better on the pc's. I have only trouble now with 2 (Windows 7) pc's.
one pc stucks at 'wait a moment' and one pc lose his connection sometimes. I'll try to solve that.
We have about 40 users and most of people have a iphone and laptop. Also all our telephones (about 50) are connected in our network. The pc have a UPT connection with the telephone.
I have checked the ip lease and there are about 180 ip adresses in use. I can reduce the DHCP scope. I know SBS 2011 have a default subnet mask 255.255.255.0, but I have changed that manually.
I don't use the network connection wizard, it shows a DHCP scope 'error' indeed.
The problem is: I am an software engineer (VS 2010) and about six months ago they ask me to manage the network. I'll do my best, but sometimes I realize my knowledge is not so much as I want. I learn very quickly :-)
one pc stucks at 'wait a moment' and one pc lose his connection sometimes. I'll try to solve that.
We have about 40 users and most of people have a iphone and laptop. Also all our telephones (about 50) are connected in our network. The pc have a UPT connection with the telephone.
I have checked the ip lease and there are about 180 ip adresses in use. I can reduce the DHCP scope. I know SBS 2011 have a default subnet mask 255.255.255.0, but I have changed that manually.
I don't use the network connection wizard, it shows a DHCP scope 'error' indeed.
The problem is: I am an software engineer (VS 2010) and about six months ago they ask me to manage the network. I'll do my best, but sometimes I realize my knowledge is not so much as I want. I learn very quickly :-)
ASKER
It looks like the problems are solved!
We did a flushdns on the first pc and the problems are gone. Please wait takes about 30 seconds before we can log in to the domain. That's ok.
We did a flushdns on the first pc and the problems are gone. Please wait takes about 30 seconds before we can log in to the domain. That's ok.
Your IP phones should really be on a separate VLAN and could use a different subnet freeing up IP's
Your IP phones should really be on a separate VLAN and could use a different subnet freeing up IP's
ASKER
Yes, I know. I realise that by myself yesterday.
Thanks for the suggestion.
Thanks for the suggestion.