Unable to PING Router On Remote Network From RAS Client

• Microsoft Windows NT Workstation versions 3.5, 3.51, and 4.0
• Microsoft Windows NT Server versions 3.5, 3.51, and 4.0
• Microsoft Windows 95

SYMPTOMS

After a Remote Access Service (RAS) client (Windows NT, Windows 95, or a third-party PPP dialer) using the TCP/IP protocol receives an IP address from the Windows NT RAS server, the RAS client is unable to PING the router on the remote network and computers beyond the router.

CAUSE

Most routers include an address resolution protocol (ARP) cache, which provides IP address to media access control (MAC) address conversion. Some routers (such as Wellfleet) can hold indefinite addresses in the cache by default. If the IP address used by the RAS client has been used on the network by a local area network (LAN) client in the past, the router can hold this IP address and MAC address in its ARP cache. When another client uses this IP address, the router ignore the packet because the MAC address of the new client does not match the MAC address in the ARP cache.

RESOLUTION

To correct this problem, check the ARP cache entries on the router. Contact the router manufacturer for more information and router configuration assistance.

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