Multiple Network Card and NFS

[don kim]

Hi...all

We have two network card and going to set up NFS server.

We are going to use Automount facility in NFS client.

I want to know how to verify which network interface is used for NFS service and change it.

Please, give some clues.
Thanks in advance.

[Dan Am]

some pointers:

rpcinfo -p
netstat -an

then block the rpc services and ports in
/var/adm/inetd.sec for the card you don't want them on.

hope that helps

[Lasse Knudsen]

Hi Don,

What is it you want to accomplish ?

Are you going to utilize 2 network cards in the NFS server. Are you looking for performance improvements or what or do you just have your server connected to 2 IP-subnets.

Are you trying to redirect some clients to access the server using one IP-addresse and others to use the second IP-address ?

Could you fill in some more details

[Byron Myers · Accepted solution]

I am assuming that each NIC is on a separate subnet. Each NIC will have an IP address with an associated system name (not necessarily the host name). On the NFS server, export your file systems. On the NFS client automount the system name of the NIC you want to do NFS over on the NFS server.
For example, on the NFS server:
150.40.30.10 mynic1
150.40.20.21 mynic2

export the file system /export/mydir

On the NFS client, the /etc/auto_master file may contain:
/mydir mynic2:/export/mydir
This will force NFS communication from the client TO the NFS server's nic with the .21 IP address.

Your NFS client should also contain a second NIC on the same subnet as mynic2. If the client does not have this second NIC, then the NFS communication from the server to the client MAY go over the other NIC. you can verify which NIC the NFS server will communicate over by doing a traceroute to the client on the server.

[don kim]

Hi... Allen.
Thank you for your concern and I am sorry about my un-detailed question.
Actually, I am trying to redirect some clients to access the server using one IP-addresse and others to use the second IP-address.

Byron's comment would be the answer for me.

[Lasse Knudsen]

Hi Don,

If your net just contains a few hosts Byrons answer is the one to go for. If you have got several hundred clients I would suggest this model:

The key in this in DNS sorting - so you should be using DNS and BIND. Your NFS server should be given 2 addresses in DNS - one for each NIC. When a client is looking up the name of the NFS server it will use the first of the addresses given from the DNS-server.

The DNS gives out the addresses in a round-robin fashion so the 2 addresses of your NFS-server are given out with the one IP-address being the first address 50% of the times. Now this does not give you the ability to control what client mounts which IP-address, but using the "sortlist" directive you can tell your DNS-server in what order they should be presented depending on the clients IP-address.

This means that you can use the same name on all machines and you can use NIS to distribute your auto mount maps. Your DNS server will take care of what clients mounts on which NIC. Could save you some time for keeping up to date version of local customized versions of auto mount maps.

Just a thought to do it what I consider the ultimate way.

You need to be running BIND 8.2.2. (which is not the one HP ships :-(

More on sortlists on:
http://www.isc.org/products/BIND/docs/config/options.html#sortlist