I'm trying to mount a folder located at 10.0.0.1:/pxe/ on eth1 but I'm not sure how to do this with two NICs enabled. The command mount 10.0.0.1:/pxe/ /mnt/pxe/ works fine when I only am using the one NIC the appropriate machine is on, but how can I specify to use eth1 when eth0 is also enabled? Thank you.
Your problem very probably has nothing to do with NFS.
NFS just uses regular IP to access other hosts, and so should work as long as the IP network is properly set up, no matter whether the data runs over two NICs, over a single NIC or over Avian Carriers.
So this most likely means that your configuration is broken for two NICs. How do you use the two NICs? Do you bond them? Do they use separate IPs? If yes, did you set up reverse DNS for both IPs? Are the routes set correctly? Etc.
The pathname "pxe" makes me believe you may want to use a "Preboot Execution Environment". There, different constrains apply. In this case, please post the exact configuration of your system and network, then we should be able to help.