honey@down.FUN (Peter Honeyman) (01/20/86)
a new version of pathalias has been posted to mod.sources. aside from time and space improvements (which appear to have reached a point of diminishing return), there are one or two major differences. ALIASES an alias used to be treated as a nickname for a host, with the primary name used in all routes. now, an alias is a distinguished, zero cost edge between a pair of hosts. aliases continue to show the same route and cost, and have the same outbound connections, but the route now shows the name by which a host is known to its predecessor. the new treatment changes the behavior of pathalias, which can lead to surprises. take, e.g., the recent renaming of utcsrgv to utcsri. in the earlier treatment, pathalias might show floyd!utcsri!user as the route to both utcsri and utcsrgv. this fails because the Systems file on floyd still says utcsrgv. under the new treatment, the route to utcsri and utcsrgv is floyd!utcsrgv!user, which succeeds. on the other hand, if map data for allegra is out of date and shows a connection to utcsrgv, pathalias might generate allegra!utcsrgv!user, which fails because allegra changed the Systems entry. the problem that motivated the change is the case of a host that really does have many names. e.g., nosc.arpa uses noscvax as its uucp name, but you had better not use seismo!noscvax.arpa!user or floyd!nosc!user. the new treatment generates the correct route for both paths. there may be some grousing about this, as it decentralizes name space control to a degree, e.g., utcsri loses some control over properties of its incoming connections. DOMAINS past syntax for domains was trashy. now, a domain is any host name that starts with dot. the rule for building a route hasn't changed, i.e., it's still weird. see the manual entry for details. if you're using the old syntax, you have to change a few characters in your input files. also, domains are now assumed to require a gateway. HOSTS.TXT HANDLING if you have access to an arpanet hosts.txt table, look in net.sources for an article titled "pathalias input from arpa hosts.txt table." this program generates pathalias input for a couple thousand internet hosts, and indicates a mechanism for accommodating domain-style routing. it's in net.sources, so don't expect too much, e.g., a man page or even a readme file. peter