Question : RPC SERVER Unavailable when trying to join domain

Hi hopefully this will be an easy one.
I have had my domain running for last few months no probs 200 + users / machines (in fact still running ok) but as per the number of machines i have my subnets getting cramped our campus network guys (they manage the network up to the building) have created me a new VLAN on another subnet currently all the machines on xxx.xx.230. the new subnet is xxx.xx.229. ive created a dhcp superscope with the scopes for each subnet and settings gateway / router etc.

started testing today by shrinking the pool on the 230 subnet and releaseing / renewing till it was full did what it should and overflowed  into the new 229 subnet, yeehah i think but then notice takes 5 mins for the machines on the new subnet to configure network connection etc etc and then when logging in active dir etc doesnt come through properly. ok dns i hear you say :) well dns is set correctly in the dhcp stuff i created a new reverse lookup zone for the new subnet everything appears to work ie ptr records update etc from the client i can prin and trace everywhere as expected but still the AD / Group Policies not coming throu properly.

login script fails and get a userenv error 1053 "windows cannot determine the user or computer name.(the rpc server is unavailable).group policy processing aborted"

whats that u say pull them off the domain and rejoin it? ok well did this and cannot join it back to the domain either as i get the rpc server unavailable trying to join the domain, dns is fine i can ping the pdc etc.

any ideas would be greatly appreciated

Answer : RPC SERVER Unavailable when trying to join domain

So all .230 subnet machines work fine but all .229 machines return "RPC unavailable" messages? Sounds like TCP port 135 is being blocked or otherwise not routed for that subnet. Check out this page for other TCP/IP ports used by Windows:
http://support.microsoft.com/kb/832017