Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!UMIX.CC.UMICH.EDU!krowitz%richter From: krowitz%richter@UMIX.CC.UMICH.EDU (David Krowitz) Newsgroups: comp.sys.apollo Subject: Re: Apollo TCP/IP gateways Message-ID: <9002021418.AA05726@richter.mit.edu> Date: 2 Feb 90 14:18:46 GMT Sender: daemon@ucbvax.BERKELEY.EDU Organization: The Internet Lines: 42 /com/crp does not rely upon TCP/IP for the underlying network packet services. The most common error with TCP/IP utilities (rlogin, lpr, telnet, ftp, etc.) is the TCP server (either /etc/tcpd under SR10 or SR9.7 BSD4.2 or /sys/tcp/tcp_server under SR9.7 Aegis) dying or loosing its host tables. A hung, or dead, tcp server is frequently the cause of a tcp socket error. The "network unreachable" error is usually caused by a local tcp server which has lost its host table, but can also be caused by a gateway that has crashed or lost its tcp server. Under Sr10, you can use the /etc/ping command to test your network connections. If "/etc/ping " works, but "/etc/ping " doesn't work, then the problem is that the gateway is either down or it's tcp server and/or routed daemon is dead. If /etc/ping does work with any of your local hosts, then the tcp server on your own machine is the culprit. Unless you have multiple gateways between your Apollo net and the outside world, run /etc/routed *only* on your gateway. Use the "/etc/route add default 1" command on your non-gateway nodes instead of routed. The routing daemon periodically flushes the tcp server's routing tables of "old" routes, and if the routing daemon on the gateway fails to update your local routing daemon you can lose all of the routing info in your local tables. If you *must* run /etc/routed on your local non-gateway nodes (ie. networks with multiple gateways to the outside world) then use the "-q" switch so that the local nodes will operate in "quiet" (ie. listen only) mode to avoid unecessary network traffic. Imagine what would happen if all 2000+ nodes on the MIT campus network were to run routing daemons all broadcasting their route tables to each other at once! -- David Krowitz krowitz@richter.mit.edu (18.83.0.109) krowitz%richter.mit.edu@eddie.mit.edu krowitz%richter.mit.edu@mitvma.bitnet (in order of decreasing preference)