I have a network question


#1

I noticed that on the Bridge web pages [ network configurations] it shows the gateway [example]

192.168.1.1.

Below it has fields for dns1 and dns2.

mine shows as

dns1= 192.168.1.1

dns2= 4.2.2.3.





other members I have checked show

dns1= 192.168.249.205

dns2= 192.168.249.206



I have 2 questions.

What is the function of these two LAN dns?

Why are some showing the 249?


#2
Gordon said: What is the function of these two LAN dns?

To "convert" names (e.g. google.com) to IP-addresses (e.g. 4.3.2.1).
Gordon said: Why are some showing the 249?

Because these are the default WLAN values:

/etc # more network_config
...
#[STATIC]
STATICWLANIP=192.168.249.242
STATICWLANMASK=255.255.255.0
STATICWLANGATEWAY=192.168.249.1
STATICWLANDNS1=192.169.249.204
STATICWLANDNS2=192.168.249.206
...

#3

@gordon DNS is required for PWD to fetch albumart if not provided by UPnP server and also for web firmware updates.

It depends on your DHCP server configuration (usually on your router).



To verify the DNS is correct you can try to use command nslookup www.psaudio.com a.b.c.d in OSX terminal or windows command line on your PC located in the same network as bridge. It either works and return something like “www.psaudio.com has address 66.40.29.165” or does not work then it returns something like “Host www.psaudio.com not found: 3(NXDOMAIN)”


#4

@alekz you was faster! grrr :slight_smile:


#5

:smiley:


#6

@alekz

yes but in your example the dns [249] matches your gateway.

don’t modern routers forward automatically anyway.


#7

Most routers get configured as the DHCP server for your Intranet, and will provide devices on the network that are connecting via DHCP their IP Address, the networks Default Gateway Address (usually the router itself) and usually a couple of DNS Addresses.

These DNS addresses are usually provided by your Internet Service Provider when your router connects and get's it's external Internet information allowing you connection to the web.  IP Address, Default Gateway...etc.

As mentioned above, these DNS servers are out there to convert destination names to routable IP addresses that the net understands.  Again as mentioned "www.psaudio.com" converts to "66.40.29.165".  You could actually enter 66.40.29.165 instead of www.psaudio.com and you'll still get to the PSA web site.

Now there are a number of DNS sites available out on the internet.  Yours are probably different then mine.  Also, the ones your ISP provides aren't necessarily the best for your location.  There are tools you can use to find which site is best for your area, and you can then change this infomation in your routers DHCP server configuration and then all your DHCP Intranet devices will get that new DNS information the next time they connect to the server.

If you configure your device for static IP you also usually need to input some DNS information if the device is going to be reaching out to the internet using Domain Names.

Your routing information above says any Domin Names needing converting should first go to your router: dns1= 192.168.1.1 (usually configured with the DNS entries provided by your ISP)

If the name can not be identified then try the second DNS: dns2= 4.2.2.3 (this is an external address of a DNS server on the web) 

Here is a good location that may shed some additional light on DNS, why it's used and how to find the best DNS sites for your area.

http://www.techsupportalert.com/how-is-ted-coding-the-fpgaent/how-find-best-dns-server.htm

This either helps...or I completly missed what you were looking for,

T

#8
@alekz
yes but in your example the dns [249] matches your gateway.


No, it does not, because my gateway is 10.0.1.138. As I said these are the default WLAN settings stored in the Bridge software.

#9

Just in case, more excerpts from /etc/network_config file (The Bridge):



#[STATIC]

STATICWLANIP=192.168.249.242

STATICWLANMASK=255.255.255.0

STATICWLANGATEWAY=192.168.249.1

STATICWLANDNS1=192.169.249.204

STATICWLANDNS2=192.168.249.206



#[STATIC]

STATICLANIP=10.0.1.19

STATICLANMASK=255.255.255.0

STATICLANGATEWAY=10.0.1.138

STATICLANDNS1=194.109.6.66

STATICLANDNS2=194.109.9.99



I do not remember what were the default settings for LAN before I changed them, but probably the same as WLAN.


#10

@alekz

What I meant was the 3rd NBR range 249 was also the 3rd in the gateway.



So dns1 That we can specify in bridge page is only for external server and has no basis

for LAN performance?



I was confused because the numbers were very similar to my router ip.

So is dns1 someone else’s server ip?

I understand ip/server name since I use “no-ip” since a while.


#11

dns1 entries can point back to your router but ultimately all DNS requests go out over the net to another server.



T


#12

@tpauline



I did a little reading and many seem to suggest that “modern routers” will send them where they need to.



I wondered if there were preferred addresses based on location and ISP?

For example… doing a speed test sometimes they let you pick the server to ping.

NY, Chicago, LA etc and they can offer different speed results based perhaps on congestion?


#13

DNS entries should point to devices that can either answer DNS queries directly, or point them to other DNS servers. Usually the router between your home network and your ISP is configured as a DNS forwarder for your home devices, but should have real DNS IPs set up to forward your requests to (can be set up automatically by your provider). The forwarder also caches DNS responses, so you may get lower DNS latency if you use your router as a DNS forwarder.



But if the routing is setup correctly, you can specify any DNS server IP in the configuration, that is able to resolve your queries.