[CentOS] How to make nodes in my local LAN see each other's names

Fri Dec 2 17:37:15 UTC 2011
Lamar Owen <lowen at pari.edu>

On Friday, December 02, 2011 11:40:39 AM Craig White wrote: 
> On Dec 2, 2011, at 9:17 AM, Lamar Owen wrote:
> > I have measured significant broadcast traffic reduction when migrating from non-WINS to WINS SMB/CIFS name resolution.
...
> As for how much broadcast occurs... A very detailed page is here...
> http://technet.microsoft.com/en-us/library/cc767893.aspx

For my LAN I measured the traffic before and after using ethereal (as Wireshark was called back then) hooked to a SPAN port on our core switch.  

A 'properly configured network with WINS' would mean all nodes on the LAN become, and stay, P-nodes (using Microsoft's terminology).  This causes a reduction in broadcast traffic, and helps in circumstances where you really care about broadcast traffic (L2TPv3 tunnels over the WAN to implement VMware vMotion is one case; bridged GRE tunnels are another, and I've run both).

Once we nailed all the non-P-nodes down to being P-nodes, I noted the reduction in broadcast traffic (again, to facilitate efficiency improvement on some layer 2 tunnelling that was necessary at the time, when the tunnels were over the then OC3 WAN link that was a layer-3 routed Packet over SONET link without EoMPLS or similar capabilities).

Since there were remote fileshares on the other end of that OC3, and since even at 150Mb/s payload rates the latency wasn't trivial, keeping broadcasts off of it was important.  And since P-nodes use unicast traffic for name resolution, latency wasn't an issue.

And on NBMA networks (I ran an ATM core for a while) broadcast name resolution is a big problem; eliminating traffic on the broadcast and unknown server (BUS) in a LAN emulation (LANE) environment can be a significant improvement, especially with slow BUS implementations.

But an 8 node LAN isn't going to notice the difference, even if all the nodes are H-nodes (the default WINS setup).

The somewhat on-topic question becomes 'how do I control node behavior in Samba on the various CentOS versions?'

That is, how do I configure Samba to be a B, P, M, or H-node (and with WINS you want it to be a P-node if broadcasts are considered harmful)?

Here's one link to a HOWTO that, while a tad old, is still relevant:
http://www.linuxtopia.org/online_books/network_administration_guides/samba_reference_guide/17_NetworkBrowsing_07.html