J.Crowcroft@CS.UCL.AC.UK (Jon Crowcroft) (07/01/89)
We are having trouble reaching a canadian site from some of our machines - it's only Ultrix 2.2 ones, not earlier (1.2) or later (3.0) or suns, hps, xeroxes, RTs, pyramids etc...they can all get throough fine. The symptom is odd: we send a SYN, and their (ultrix 3.0) never replies, else they send a SYN, and we never reply - the packets look fine by tcpdump; anyone got any clues...(cannot be filtering, coz we can ping them with any packet sizes...) thanks jon