DNS issues, not sure how to fix

[gurutech]

I just replaced my Win8 machine with Centos 6.3, and everything seems to be fine (everything I have tested so far), except DNS on my local network. I have forced my NIC to use my router as the DNS server (which in turn uses my ISP info for DNS lookups). I can get to this website, Yahoo, etc... no problems, but anything on my local network, I have to access via IP address.

I have another Linux machine (F17), and can access everything via name and IP address. Not using "hosts" file.

Also, on my F17 machine, if I ping "pcname", I get a weird IP address in return, but I get responses. If I ping "pcname.local", I get the correct local IP address. (I'm not referring to an IPv6 address... I get a 66.55.23.33 or something like that...)

I've tried looking up the DNS issue, but the only things I have found refer to the Linux machine being the DNS server, which is not the case for me.

[george_toolan]

Check your nameserver configuration

cat /etc/resolv.conf

Does this just show your router's ip address as name server?

What's the ip address of your router? Try

host pcname ip-address-of-your-router

where ip-address-of-your-router is the ip address of your router ;-)

This would only work if you've configured your pc names inside your router's dns server.

If everything else fails try the "hosts" file.

[jpollard]

Local network DNS support is not usually done unless the router from the ISP provides DHCP (and associated names) support for your local machines.

Windows domains always provide their own DNS.

[gurutech]

ISP didn't provide a router, just the cable modem. I have it connected to a VPN/Firewall which gets its IP from the ISP, then acts as a DNS/DHCP server for the rest of my network.

the cat /etc/resolv.conf shows:

# Generated by NetworkManager
search local
nameserver 192.168.x.x   (my router's IP)

This is how I have all my machines configured, so they check the router for local names, and the router will "forward" the request to the ISP for everything else.

[jpollard]

FYI, the cable modem IS a router.

And "search local" doesn't mean local names - it means for names without a FQDN append the name "local". How the router actually handles unknown names and incomplete domains is not what you expect.

When I "nslookup pcname" (my /etc/resolv has "search home") the response is:

$ nslookup pcname
Server:		192.168.1.1
Address:	192.168.1.1#53

Non-authoritative answer:
Name:	pcname
Address: 8.15.7.117
Name:	pcname
Address: 63.251.179.13

$

Which (according to dig) is controlled by Verisign.

From the manpage on resolv.conf:

domain Local domain name.
              Most queries for names within this domain can  use  short  names
              relative  to  the  local domain.  If no domain entry is present,
              the domain is determined from the  local  hostname  returned  by
              gethostname(2);  the domain part is taken to be everything after
              the first '.'.  Finally, if the  hostname  does  not  contain  a
              domain part, the root domain is assumed.

So if you don't have a FQDN specified as your host name, you get pcname. (the period is the end of the FQDN specifying the root domain).

Now you might try adding "domain local" and see if that changes anything for you. This specifies that the domain name for the host is "local" rather than just using the root domain.

[gurutech]

Tried adding the domain local line to my resolv.conf file, but didn't help.

Checked the file on my other linux machine and it had 3 nameservers - my local one, and the two from my ISP, so I matched that content to this machine, and still not working.

Checked both machines with nslookup - if I don't specify ".local" at the end, I get the IP 67.63.55.3 no matter what name I look up. If I try looking up a name with the .local, it can't be found ** server can't find pcname.local: NXDOMAIN

Tried resetting the NIC, and even removing my router IP from the list of nameservers.

Edit: I guess if need be, I can configure one machine as a DNS server and go from there. Would save me from having to set a hosts file for all my Linux machines.

[gurutech]

ok, another update... was just clicking around, and discovered that if I go to Places, then Network, I can SEE the computers online that I can't ping/tracert to, and can access the shares on these machines. But I still can't access them from a terminal window using ping. Keep getting "unknown host" errors....

[jpollard]

Difference in what you are doing.

You are using ping with names.

The network lists are not done that way.

[gurutech]

so how do I get ping and stuff to work? It is a DNS issue, correct?

[george_toolan]

You have to configure the names inside your router.

pcname does not exist:

$ host pcname 8.8.8.8
Using domain server:
Name: 8.8.8.8
Address: 8.8.8.8#53
Aliases: 

Host pcname not found: 3(NXDOMAIN)

Does your ISP use spamming DNS servers?

Some broken DNS servers will give you an answer to everything instead of the correct answer "NXDOMAIN".

This would also explain why you're getting the same "wrong" ip address for non-existing hosts.

Your router would only be able to resolve a local address if it doesn't exist on the "real" internet.

$ host morpork 192.168.2.1
Using domain server:
Name: 192.168.2.1
Address: 192.168.2.1#53
Aliases: 

morpork has address 192.168.2.4

[gurutech]

I don't see anywhere inside my router where I can do what you are suggesting. I have the "admin" interface, but it doesn't have anything related to DNS, other than DDNS, and a place to hard-code an IP address if I don't want to use the default ones given by my ISP. I have tried leaving this blank and using only my default ISP DNS, as well as hardcoding the IP of the router, but I get the same results either way.

Not sure how to configure BIND on a Linux machine. I have it installed, but can't figure out how to set it up to be the DNS server internally, and forward anything it can't find to my ISP's DNS servers. I could do it on a Windoes server, but not Linux. (Don't have a Win server to use though...)