okay, so i've b!tched about this before already. i'd just like someone to properly explain to me why the following scenario doesn't work.
before i even GET to the scenario, please see the youtube video i posted so you can FULLY UNDERSTAND EXACTLY what's going on:
[The YouTube Video link has been removed because it had the F-bomb in it... ISN'T THAT SILLY??] - removed by Cindy Toy, Cisco Small Business Support Community Manager
What you will see in that video is the details on my window's boxes network configuration. you'll initially see that my address is from the private scope as "10.10.10.111". You'll see that my subnet mask is "255.255.255.0". You'll see that my default gateway and DHCP server are set to "10.10.10.1". This is my RVS4000. then you'll see that i have 2 dns servers start with the "208" address. these are OPENDNS servers. i get these addresses from my DHCP server (because i've set up my RVS4000 to use custom DNS - these 208 addressess - which actually means that the RVS will simply send my DHCP clients custom DNS servers)
At this point, it's important to recognize that my windows client in the video is using the "208..." addresses for DNS queries. i then attempt to ping a NETBIOS name "nas". the address comes back with an ip of "18.104.22.168". This address is the "ooops cant resolve that DNS name for opendns" portal page. that is to say that when i tried to do an NETBIOS lookup of the name nas, the DNS servers attempted to find "nas", couldn't and sent me to a portal page. simple.
i then go back to my network properties of my adapter. from here we confirm that i got my DNS servers from my DHCP server, the RVS4000. i then change my DNS server to the RVS4000. we all know that the RVS4000 isn't a DNS server. it will simply forward the DNS requests out the door to my ISP's DNS servers (because the RVS4000 itself is a DHCP client to my ISPs network and has received it's own set of DNS entries).
i verify the network configuration in the video at this point. you can clearly see that my RVS4000 is my gateway, my DHCP server, and my DNS server (the latter in which i showed you i manually configured).
i then attempt to ping the netbios name "nas". holy @#$% it works. i clear the screen and do it again. still works. so i change back to my DHCP server giving me custom DNS servers. i verify the change. IMMEDIATLY, i stop being able to resolve the netbios name. and basically the rest of the video is just me proving again that netbios works, but ONLY IF I DONT HAVE CUSTOM DNS servers.
after all that, what is my issue you ask??
WHY is it that NETBIOS fails when the RVS4000 sends my clients custom DNS servers???
lets consider the name resolution order on a windows PC:
and here's the technical overview
Windows checks whether the host name is the same as the local host name.
If the host name and local host name are not the same, Windows searches the DNS client resolver cache.
If the host name cannot be resolved using the DNS client resolver cache, Windows sends DNS Name Query Request messages to its configured DNS servers.
If the host name is a single-label name (such as server1) and cannot be resolved using the configured DNS servers, Windows converts the host name to a NetBIOS name and checks its local NetBIOS name cache.
Windows creates the 16-byte NetBIOS name by converting the host name, which must be less than 16 bytes long, to uppercase and padding it with space characters if needed to create the first 15 bytes of the NetBIOS name. Then, Windows adds 0x00 as the last byte. Every Windows-based computer running the Workstation service registers its computer name with a 0x00 as the last byte. Therefore, the NetBIOS form of the host name will typically resolve to the IPv4 address of the computer that has a NetBIOS computer name that matches the host name.
If the host name is 16 characters or longer or an FQDN, Windows does not convert it to a NetBIOS name or try to resolve the host name using NetBIOS techniques.
If Windows cannot find the NetBIOS name in the NetBIOS name cache, Windows contacts its configured WINS servers.
If Windows cannot resolve the NetBIOS name by querying its configured WINS servers, Windows broadcasts as many as three NetBIOS Name Query Request messages on the directly attached subnet.
If there is no reply to the NetBIOS Name Query Request messages, Windows searches the local Lmhosts file.
SO I RESTATE:
why can't my network devices (in this case, a laptop but it's network wide dont worry) perform a netbios lookup when my router passes a client a DNS server that is not the router itself???
someone PLEASE EXPLAIN THIS TO ME!!!!! you saw netbios work when the client sends its DNS requests to my router (10.10.10.1), but it FAILS when my client has a DNS server given to it by the router, where that DNS server is not the router itself!!!!
Message was edited by: Cindy Toy