Be sure to (at least) rename networks to the names used in the pool before joining the new host!

When you add a host to a pool, most things are taken care of for you. However, you will need to configure 'management' interfaces (interfaces with IP addresses) ahead of time or the pool join operations will not work as expected.

For reference:

xe network-list

Configure the same labels as on the pool master changing the MTU if necessary for storage networks:

xe network-list

xe network-param-set name-label=Management uuid=<UUID-xenbr0>
xe network-param-set name-label=GuestPublic uuid=<UUID-xenbr1>
xe network-param-set name-label=BlockStorage MTU=9000 uuid=<UUID-xenbr2> 
xe network-param-set name-label=FileStorage MTU=9000 uuid=<UUID-xenbr3>

The Management interface is configured during XenServer installation, usually eth0.

NICs for VM traffic don't get IP addresses (are not 'management' networks).

Configure IP addresses and storage network parameters for other 'management' networks:

xe pif-list host-name-label=<New XS Host Name>
xe pif-reconfigure-ip IP=<ip-on-storage-net> mode=static netmask=<subnet-mask-of-storage-net> uuid=<storage-nic-uuid>
xe pif-param-set disallow-unplug=true other-config:management_purpose="Storage" uuid=<storage-nic-uuid>

Then join the new host using XenCenter.