dennis%cod@NOSC.ARPA (Dennis Cottel) (01/23/87)
I seem to have a bug in the Apollo TCP code when talking to UNIX 4.3 BSD through a gateway. Apollo doesn't have a 4.3 system to verify this. Has anyone else seen it, or can anyone confirm the problem? Configuration: Any Apollo node (SR9.2.3, DOMAIN/IX 9.2.3, TCP 2.1) through an Apollo gateway (DSP80A, COM-ETH) to a VAX running UNIX 4.3 BSD. Symptom: The standard input provided to /usr/ucb/rsh contains duplicated data when delivered to the remote command running on the VAX. Details: As an example, if you execute (on an Apollo node) the command cat somefile | rsh unixhost lpr groups of 512 characters are duplicated in the printout. What is happening is that after a certain number of 1024-byte blocks (usually ten) are correctly transmitted, the VAX receives the next 512 bytes twice. This pattern of repetition continues, with the reception of (n*1024 + 512) bytes (where n varies from 0 to 2 or 3) and then the duplication of the last 512 bytes. When talking to a 4.2 BSD system, the Apollo software uses 1024-byte TCP packets. 4.3 BSD apparently has logic that sets the packet size down to 512 bytes if the path includes a gateway. The problem doesn't appear when the remote host is running 4.2 BSD, or when both nodes are on the same Apollo ring. Also, there is no problem with FTP, TELNET, or RCP. Dennis Cottel Naval Ocean Systems Center, San Diego, CA 92152 (619) 225-2406 dennis@NOSC.MIL sdcsvax!noscvax!dennis