routing table wierdness

[Joe Bush]

	Lately the routing tables on an MicroVAX 3900 running Ultrix
3.1 have started to include "host" information in the "destination"
and "gateway" fields produced by the "netstat -r" command. 
	For example, previously, the output from the "netstat -r"
command returned only that information statically added by the "route"
command (we are NOT running the notorious "routed"). That is, it
returned the standard, "localhost" and "ethernet" destinations, as
well as, a few REAL gateways (and the network destinations that could
be reached from gateways). 
	For example, here is the output from a VAXStation 3100
(running Ultrix 3.1) on the very same network that still behaves
in the old familiar manner:

-----------------------------------------------------------------------
Routing tables
Destination          Gateway              Flags    Refcnt Use        Interface
localhost            localhost            UH       0      3          lo0
eesun1-net           eesun1               UG       0      0          se0
default              uta1                 UG       0      27         se0
csun5-net            csun5                UG       0      0          se0
meap-net             meap                 UG       0      0          se0
ethernet             escro                U        3      68619      se0
-----------------------------------------------------------------------

	But for reasons I can't explain, the MicroVAX 3900 is
suddenly loading up its routing tables with "host" info. None
of the "hosts" (ie., those records where the destination and
gateway field are the same and UGHD in the "Flags" field) are 
gateways. Here is a typical execution of "netstat -r" on the
MicroVAX 3900:

-----------------------------------------------------------------------
Routing tables
Destination          Gateway              Flags    Refcnt Use        Interface
localhost            localhost            UH       0      3          lo0
eesun1-net           eesun1               UG       0      0          qe0
meap-net             meap                 UG       0      0          qe0
default              uta1                 UG       1      115678     qe0
csun5-net            csun5                UG       6      685680     qe0
ethernet             evax                 U        0      4964       qe0
ksun                 ksun                 UGHD     0      5          qe0
mac-ii-rm314         mac-ii-rm314         UGHD     0      258        qe0
mac-ii-kamangar      mac-ii-kamangar      UGHD     0      860        qe0
escro                escro                UGHD     0      15566      qe0
mac-se-grabow        mac-se-grabow        UGHD     0      938        qe0
tandy-4k-rm118       tandy-4k-rm118       UGHD     0      2346       qe0
129.107.2.91         129.107.2.91         UGHD     0      24         qe0
129.107.2.27         129.107.2.27         UGHD     0      1970       qe0
utacfd               utacfd               UGHD     0      30         qe0
129.107.2.171        129.107.2.171        UGHD     1      2297       qe0
csun1                csun1                UGHD     0      1411       qe0
129.107.2.59         129.107.2.59         UGHD     0      2515       qe0
mac-se-kavi          mac-se-kavi          UGHD     0      4459       qe0
meap                 meap                 UGHD     0      7201       qe0
csejos               csejos               UGHD     0      1808       qe0
csun2                csun2                UGHD     0      11557      qe0
129.107.2.93         129.107.2.93         UGHD     0      444        qe0
mac-se-weems         mac-se-weems         UGHD     0      1623       qe0
csun4                csun4                UGHD     0      6432       qe0
eene                 eene                 UGHD     0      64         qe0
cracs1               cracs1               UGHD     0      1653       qe0
129.107.2.94         129.107.2.94         UGHD     0      993        qe0
agnos                agnos                UGHD     0      100        qe0
utat4                utat4                UGHD     0      1402       qe0
cracs2               cracs2               UGHD     0      2174       qe0
tandy-3k-muths       tandy-3k-muths       UGHD     0      1089       qe0
thingol              thingol              UGHD     0      170        qe0
mac-se-umbaugh       mac-se-umbaugh       UGHD     0      3989       qe0
------------------------------------------------------------------------

	I can find no reason to explain why the MicroVAX is
suddenly including all this host information in its routing
tables (ie., the records with the UGHD value flags field). Both
machines have their "routed" turned off, use /etc/rc.local "static"
routing, and the same broadcast and netmask values. In addition,
each machine has only one ethernet interface (ie., does not serve
as a gateway). Also curious is the response time to the "netstat -r"
command on the MicroVAX. It used to take just a second to return
(as the VAXstation still does) but now takes over two minutes to
return, essentially independent system load.
	Can any one hassard a guess as to what might be causing this
strange phemonena? In addition, why would routing tables *ever*
want to include "host" info in this manner?
	Note that when the route tables are flushed with a "route -f"
the "host" data returns in after 5-10 minutes under normal work loads.

	- Joe

















-- 
	  bush at evax.arl.utexas.edu		  Vax Systems Manager
	  (817) 273 - 3333			  CSE Dept. UT-Arlington
	  Office Rm 221 EB2			  403 South Cooper
	  P.O. Box 19015			  Arlington, Texas 76019