All, We have a bunch of 2530, HPE5500 and HPE5700 switches in a flat network. We needed to expand the IP address space so we changed the mask on our Firewall and devices from 192.168.50.0/24 to a 192.168.50.0/23. The majority of new addresses were added to DHCP in the top of the range (192.168.50.246 thru 192.168.51.254). If I come from a host 192.168.50.92 (original /24) I can ping and access a server at 192.168.50.60 (original /24) and I can also ping a new DHCP host at 192.168.51.254 (newly expanded dhcp scope) But if I try to come from DHCP host at 192.168.51.254 back the other way to 192.168.50.60 I cannot access it or ping it but yet I can see the mac address show up in the Arp Cache on the host. There are no other routers in this network so it makes no sense whatsoever. Any Ideas?