time@tbomb.ice.com (Tim Endres) (12/06/90)
In article <RZ9PT1w163w@bluemoon.uucp>, grant@bluemoon.uucp (Grant DeLorean) writes: > I guess I should go look at the maps before speaking, but why have > yourself listed in the maps as connecting to other systems with a > full map entry if you don't want mail mapped through you? Since the > This is required so that people know how to get mail *to* me as well as *through* me. If I don't list the hosts I talk to, you don't know how to get to me. Now, there is a means of specifying that your host is a "leaf" node, allowing pathalias et.al. to determine not to route mail through you. Of course, the case in which you wish to forward mail downward(out?), but not upward(in?), I have never seen before, but I suspect that even this can be handled. It is a *directed* graph after all. tim. ------------------------------------------------------------- Tim Endres | time@ice.com ICE Engineering | uupsi!ice.com!time 8840 Main Street | Whitmore Lake MI. 48189 | (313) 449 8288
david@dhw68k.cts.com (David H. Wolfskill) (12/10/90)
In an article, someone wrote: >> why have >> yourself listed in the maps as connecting to other systems with a >> full map entry if you don't want mail mapped through you? >This is required so that people know how to get mail *to* me as well >as *through* me. If I don't list the hosts I talk to, you don't know >how to get to me. This, with respect to the use of mailers that make use of the output of pathalias, is not the case. Suppose we feed the following to pathalias as if we were at site foo1: bar foo1(DEMAND), foo2(DIRECT) foo1 foo3(DEMAND), bar(DEMAND) $ pathalias -l foo1 -c 0 foo1 %s 300 bar bar!%s 500 foo2 bar!foo2!%s 300 foo3 foo3!%s In the above, pathalias is showing that to get from foo1 to foo2 -- even though there were no lines in the above that would rationally have been in a map entry for "foo2." On the other hand, it would be of some benefit to site "foo2" to have a map entry: * It would make it easier for an SA there to run pathalias -- though such a site might well use smail's "smart-host" specification. * It would also make a "batter" claim to the valuable name :-) than the lack of a map entry would. * It would allow some of us an opportunity to get some idea how serious the folks at foo2 are about UUCP mail. :-) >Now, there is a means of specifying that your host is a "leaf" node, >allowing pathalias et.al. to determine not to route mail through you. This is true, but only works well if *all* sites that show a link to you use it -- if at least one site does not, pathalias tends to notice, and route mail through the "terminal" site that way. :-( I find that in practice, I use the "DEAD" specification (either "-d site" on the command line or "dead {site}" in the pathalias input) in order to achieve the desired effect of using the site in question as a "last resort." Cheers, david -- David H. Wolfskill uucp: ...{spsd,zardoz,felix}!dhw68k!david InterNet: david@dhw68k.cts.com CompuServe: >internet:david@dhw68k.cts.com
lyndon@cs.athabascau.ca (Lyndon Nerenberg) (12/12/90)
time@tbomb.ice.com (Tim Endres) writes: >In article <RZ9PT1w163w@bluemoon.uucp>, grant@bluemoon.uucp (Grant DeLorean) writes: >> I guess I should go look at the maps before speaking, but why have >> yourself listed in the maps as connecting to other systems with a >> full map entry if you don't want mail mapped through you? Since the >> >This is required so that people know how to get mail *to* me as well >as *through* me. If I don't list the hosts I talk to, you don't know >how to get to me. Please read the documentation for pathalias. When you list a site in your map entry, you are indicating that YOU are willing to forward to THEM, not the other way around. There is one, and only one, exception to the above rule. Consider the following map entries: foo bar(DIRECT) bar mumble(DEMAND), frotz(EVENING) Foo indicates a single connection to bar for their outgoing mail, however bar does not indicate a reverse connection. In the absence of *any* *other* connections to foo, pathalias will imply a very high cost route from bar to foo so that foo is not unreachable from the rest of the net. Note that this only happens in the case of an isolated leaf node with no advertised reverse links. If you want the rest of the net to know about links from other sites TO you, have those other sites advertise that connection in THEIR map entry. -- Lyndon Nerenberg VE6BBM / Computing Services / Athabasca University {alberta,cbmvax,mips}!atha!lyndon || lyndon@cs.athabascau.ca Packet: ve6bbm@ve6mc [.ab.can.na] The only thing open about OSF is their mouth. --Chuck Musciano