AS/400 Conectivity Problem

We have installed an AS\400 to our NT Network and are having problems connecting to our WAN. We configured our default gateway which is our firewall in the AS\400, but it hasnt helped.We have no trouble with connecting to any workstation on the local Network. also for some reason I cannot ping our router, but I have no problem getting over the network to our remote sights, from our workstations and Servers.Also when I loaded the ibm client software on our remote workstations it failed the connectivity test to the as\400. I checked network neighborhood and it the as400 wasnt there, but every other node was. Please help. Thanks TBG