I would recommend configuring a loopback interface on the router, and put
its IP address in the forward DNS table. If you do not use a loopback
interface, then you must pick one of the real interfaces, fddi 0/1 in your
case. If fddi 0/1 is down, then NetView cannot communicate with the router,
or anything "beyond" it. If there are multiple paths in your network, i.e.
NetView could talk to the router through one of the Ethernet interfaces,
then the loopback interface will provide better connectivity. If NetView
only has a single path to the router through the fddi interface, then you
already have the best setup. In other words, the design/configuration of
your network, and where the NetView server resides are factors in the
DNS/loopback configuration.
The reverse DNS table you listed has unique names for each IP address. I
would recommend making them all the same name. That way whenever NetView
"sees" one of those IP addresses (in a trap, netmon discovery, etc.) it will
be associated with the same name and object in the database. I have seen
times when NetView creates multiple objects for the same router just because
it was discovered through different interfaces. Reliable name lookups, and
SNMP communication, will avoid this problem. Different hostnames on each IP
address just aggravate this problem.
If you do not use a loopback interface, then to make your DNS administration
easy, you should probably just put all 3 addresses in both DNS tables. In
this scenario, you need to know whether your DNS has round-robin support.
If it does, then the name lookups for the router will return each IP
address, i.e. 157.184.187.1 the 1st time, 157.184.193.1 the 2d time,
157.184.196.1 the 3d time, and then back to the first IP address the 4th
time.
> -----Original Message-----
> From: Dan Cox [SMTP:dcox@LEXMARK.COM]
> Sent: Wednesday, June 24, 1998 08:06
> To: NV-L@UCSBVM.UCSB.EDU
> Subject: Re: Netview and node names
>
> So what is meant here is that if you have a router with say fddi 0/1,
> ethernet 1/1 and ethernet 1/2.
> All theese are on bbr1.rtr.noc.lexmark.com.
> fddi 0/1 (157.184.187.1 255.255.255.0) (backbone)
> ethernet 1/1 (157.184.193.1 255.255.255.0)
> ethernet 1/2 (157.184.196.1 255.255.255.0)
> Is this what I would put in DNS ?
> Forward DNS
> bbr1.rtr.noc.lexmark.com = 157.184.187.1
>
> Reverse DNS
> 157.184.187.1 = bbr1fddi0-1.rtr.noc.lexmark.com
> 157.184.190.1 = bbr1eth1-1.rtr.noc.lexmark.com
> 157.184.193.1 = bbr1eth1-2.rtr.noc.lexmark.com
>
>
>
>
> "Joel A. Gerber" <joel.gerber%USAA.COM@interlock.lexmark.com> on 06/19/98
> 20:27:54
>
> Please respond to Discussion of IBM NetView and POLYCENTER Manager on
> NetView et alia <NV-L%ucsbvm.ucsb.edu@interlock.lexmark.com>
>
> To: NV-L%ucsbvm.ucsb.edu@interlock.lexmark.com
> cc: (bcc: Dan Cox)
> bcc: Dan Cox
> Subject: Re: Netview and node names
>
>
>
>
> Routers and DNS have given us fits, too. In general, I have found that
> NetView works best with routers if you configure a loopback interface on
> the
> router, and put its IP address in DNS. Additionally, define ALL of the
> router's IP addresses in DNS, but only in the reverse lookup table.
> NetView
> does a lot of reverse lookups, i.e. what is the host name for address
> 1.2.3.4? If the reverse lookups all resolve to the same name, and the
> forward lookups only resolve to one address, then NetView will have fairly
> reliable communication with the router.
>
> > -----Original Message-----
> > From: Keith Monroe [SMTP:keithm@NERSP.NERDC.UFL.EDU]
> > Sent: Friday, June 19, 1998 14:41
> > To: NV-L@UCSBVM.UCSB.EDU
> > Subject: Netview and node names
> >
> > I have searched the list archives and can't find an answer, so I'm
> > posting here for insight.
> >
> > From what I have seen, Netview doesn't like nodes (ie: routers) to have
> > an IP address as the object name. It will search down the list of
> > interfaces and find one that has a DNS entry and change the object name
> > to it. Is there a way to keep Netview from doing this? I have also
> > noticed that Netview will, at times, change the object name from what it
> >
> > was discovered as to another interface name. Any ideas why?
> >
> > The reason I want to be able to do this is because it can cause SNMP
> > query problems. Here's an example:
> >
> > Router A has a link to us that has no DNS entry. I add the object to
> > the map with the IP address. Netview queries the router and discovers
> > all of the interfaces. All seems ok. For some reason (hopefully to be
> > explained by someone), Netview changes the object name to one of the
> > interface that has a DNS entry. Now every SNMP operation uses that new
> > name. If this name is not in your SNMP configuration all queries will
> > fail. Sure I can change the symbol and selection name for the router,
> > but that still doesn't help me with the SNMP problem.
> >
> > Any ideas would be greatly appreciated...
> >
> > --
> > Keith Monroe E-mail: keith@ufl.edu
> > NorthEast Regional Data Center Voice: (352)392-2061 / Suncom
> > 622-2061
> > University of Florida Fax: (352)392-9440
|