In the popular tradition of replying to my own post ... It seems that this problem started right around the time I changed our BGP configuration. I did: config term route-map att_out permit 9999 set as-path prepend 19317 19317 exit clear ip bgp 12.87.125.249 out This change was to increase our prepending of our own AS path from 1 to two. It was: set as-path prepend 19317 And we /could/ have had another host with a similar problem but with a different end point, this time in Canada, and the (outbound) route to our Canadian server does not transit either Level3 or Shaw cable. We did not identify exactly when it started working again, we were poking around this problem and then happened to check and it was working. It is *possible*, but by no means confirmed, that a traceroute allowed to go through all its timeouts to the Canadian server may have also switched that problem off too. Doug "Still searching for answers" Rand.