I have an Alpha/Linux machine connected via a Linksys 5-port hub to a Wintel PC. The PC is connected to the phone via a modem, and is running a Vicomsoft router. I can successfully make TCP connections (ftp, telnet, etc) from the Alpha to the PC, and from the PC to the Alpha. I can also make TCP connections out to external machines from the PC. But whenever I try to make an external TCP connection from the Alpha, I get one of the errors ENETUNREACH or EHOSTUNREACH (network is unreachable, or no route to host). This is very strange, because I can "ping" the external address, and the procedure "gethostbyname" communicates successfully with an external nameserver (implying that UDP connections work). Since I don't see how it's possible for RAW and UDP protocols to work but not TCP, I can only assume this is a Linux bug (or incompatibility of some kind). This view is further supported by the fact that if I disconnect the wire from the Alpha and plug it into another Wintel laptop, that laptop can make TCP connections through the router just fine. (Also, at another site, the same router running on a Wintel PC works with both other Wintel machines and Macs.) If it's any help, the configuration info is as follows: PC IP address = 192.168.1.1, Alpha = 192.168.1.2, router = 192.168.1.254. netstat -nr gives Destination Gateway Genmask Flags ... Iface ----------- ------- ------- ----- ----- 192.168.1.0 0.0.0.0 255.255.255.0 U eth0 127.0.0.0 0.0.0.0 255.0.0.0 U lo 0.0.0.0 192.168.1.254 0.0.0.0 UG eth0 Any help you can give me with this problem would be much appreciated -- if I can't get this to work, I shall have to switch to another OS ....
There are no known problems with TCP connections on alpha. Check your hub configuration -- if necessary, assign exactly the same IP address to the alpha as one of your known-to-work PC's and try your experiments.