OK, I have used the following command:- ssh -fC2qTnN -D 1080 chris@xxxxxxx ... and it results in exactly the same error as I originally reported. So I don't think the port number matters and the certificates at isbd.uk are up to date. As I said I'm pretty certain it's something more that Firefox is now demanding, but I don't know what. Thanks for your reply, just bouncing ideas back and forth can often sort this sort of thing out. -- Chris Green _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev