DNS issue in LAN - network slow down

O

openmind

Senior Member
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Dec 1, 2013
Messages
24
Hi All,

Our network is in workgroup but not in domain because of most of the computers in the office are home edition operating systems. Though we have windows server 2012 as a file server.

Our issue is the network slow, by analyzing I found the issue may be with the computers cannot identify the other computers with their computer name, I mean DNS issue in LAN.

INTERNET is working fine. The DHCP server giving all computers the gateway ip to firewall ip and DNS primary server as ISP IP which is external one.

when I execute the command "nbtstat -r" which gives results related to Netbios /lookup functionality, here in results "Resolved by Broadcast " should be zero but I am getting some 77 value. It means its confirming that some broadcast issue is there because of computers cannot lookup with the computer names.

So whether I need to create a local DNS server to resolve computers like "storage-pc" -> 192.168.1.11 ,"antivirus-pc" -> 192.168.1.12 etc.,. ??? but except some pcs all are DHCP clients.

Please suggest me ,I have no idea what to do !!!
 
Solution
Fyi as this is a workgroup and not a domain, I assumed the router rans your main dhcp; so yes in that case the server has dns1 as 192.168.1.7 and dns2 is 192.168.2.1
I'd set the router dns1 as 192.168.1.7 i.e. the server and the second as your isp or perhaps even google… the general idea is to send any local dns requests back into the system before they get outside.

The server gets top billing so that local files i.e. stored on the network file server can be located by machines within the workgroup but not controlled by the server... since this isn't a domain we have to account for that dns routing issue.

However;
You have a firewall and that adds some extra options so dns (on your firewall) can be passed through from/ to...
Below output from Wireless Device (laptop)



Below output from Desktop ( cabled computer ):



Here in the above two cases I was pinging to Firewall ( 192.168.1.1) ,Router ( 192.168.2.1) and Yahoo website ( www.yahoo.com), nearly at the same time....

I think if any rule in Firewall is blocking ping then it should not able to ping at all, but here it's pinging and then request timed out and then pinging again........what do you say ?

Not sure what to do, from where to start....!
 

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What if I create static DHCP to all devices then I will map the computer names with ips allocated on paper.....
I may need to do this for purpose of getting reports on firewall based on user names ,so I run one virtual machine on that some DNS server even to resolve the local computers and forward to router for external things on some CentOS or free open source DNS server ( maraDNS )....!!!

What do you say ?
 
Above issue I have posted (ping screenshots ) seems to be related to Access Point as I have observed, I will see for that....

Thanking You !
 
Yes if you want to test it but I doubt you would see any difference, performance is measured at the weakest point and in your case that is the wireless access.

Your land line network is only idling along because all the traffic is jammed into wireless… the virtual access for phones also adds some lag as well.
 
I have replaced one Access Point which I was suspecting to be not working fine.
 
I am not getting good speed over wireless devices I have observed.
Though the Access Points are not set for 5 Ghz and wireless devices are not supporting 5 Ghz , in 2.4 Ghz environment it should get at least 100 Mbps I think , isn't it ?

Below are the details about wireless settings and environment.


here I think my laptop doesn't support 5 Ghz.



here I set the Access Point to both 20 MHz and 40 MHz ,but the same speed 65 Mbps as in following image...



But for my friend who is having some older Dell laptop was getting double speed we are getting i.e.,. around 140Mbps...
I am wondering he is getting even he have older laptop and I have HP laptop which is 8 months older...



In his laptop I found he can set some settings like use 20 MHz or 40 MHz something like that ,but in my computer I don't find any settings.


Please suggest to improve the speed !

Thanking You !
 
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