(Sigh) When they have a different name on every interface, then I
have to put a name in /etc/hosts for every interface, all with the
same name, using the one I like best first. That overrides all of
the responses from DNS. This is sort of automatable using rnetstat -I
and piping it into awk. The name will always resolve to the first
address, and all of the addresses will resolve to the same name.
I think people do that sort of naming as a kind of bookkeeping,
but once Netview is up and running, it is no longer as useful, since
Netview shows you clearly what is what.
Netview can tell which interfaces are HSRP, and handle them properly
(if you are at 5.1.1.) It correctly moves them from one device to another
when that action happens. You must be sure that the sysname is different
on both devices. Check the trapd.log for HSRP records. Those
interfaces I leave out of the /etc/hosts and definitely leave them
out of the seedfile. Only one entry in the seedfile per device and
make sure it is NOT the hsrp interface. You can prevent the discovery
of a node by the HSRP interface, I believe, if you quickly discover
the real devices first by some other interface. Leaving it to chance
seems to lead to problems like this. So I always get the customer
to tell me exactly what their HSRP arrangements are up front, then
force the discovery if the devices involved with explicit entries
in the seedfile. If you carefully examine the address table with
rnetstat, you can see which device has the interface at any given
time. Make sure you know which device you are querying, though. I
use 'snmpwalk <someaddr> system' and check sysname and uptime to
distinguish devices. If something has already been found by an
interface that is not permanent, delete the device and redisover it.
Note that duplicate IP addresses for backup use is not the same case
as HSRP. That sort of thing is also handled by Netview, but differently.
Netview will complain briefly about the duplicate, but if one of them
is Administratively Down, it will understand what you are doing and
add it anyway. There is some discussion of this behavior in the
man page for netmon, or in the online help you see when you use the
daemon configuration options for netmon on the Tivoli desktop.
Cordially,
Leslie A. Clark
IBM Global Services - Systems Mgmt & Networking
Actually, our Clients uses a different name for every router interface.
Most of the time I can fix the problem by deleting the other
interfaces and demand poll one. The problem arises when I see HSRP
running, we are using the standard x.x.x.1 for the virtual, and x.x.x.2
and x.x.x.3 for the actual interface address. For some reason, all the
x.x.x.1's still resolves in the DNS. I can't simply delete the
interfaces and demandpoll one because the virtual address actually
points to a existing router and will discover the x.2 or x.3 addresses
which already exist. So netview will ignore it.
Unless, our client fixes the DNS (not likely), or there is a way to
specify which router has HSRP (which I believe there aren't currently,
but it would be a nice addition), I am currently SOL. I am currently
just going to create a location object, and just group all those HSRP
interfaces in there for cosmetic purposes.
--- Leslie Clark <lclark@US.IBM.COM> wrote:
> Having all interfaces named in DNS should not cause a problem for
Netview.
> It is the preferred approach, as long as all of the names are the same.
> That is unless something has changed. I'm getting suspicious, though. In
> the cases where you are seeing two nodes, does the DNS
> use the round-robin approach?
> That is, does it resolve the name to a differentaddress each time? I've
> seen this a couple of times lately and it seemed to coincide with this
sort of
> problem. If that's the case, it seems like putting one entry in
/etc/hosts
> for the router would solve the problem. With /etc/netsvc.conf set to
> hosts=local,bind the name would always resolve to the one address,
> and the rest of the addresses would resolve to the single name in DNS.
>
> Another possiblity is that they are using HSRP and DNS has maybe a little
> too much information regarding the hsrp interface. This part always
confuses
> me, so I won't say any more about that.
>
> Cordially,
>
> Leslie A. Clark
> IBM Global Services - Systems Mgmt & Networking
> (248) 552-4968 Voicemail, Fax, Pager
>
>
> ---------------------- Forwarded by Leslie
> Clark/Southfield/IBM on 04/19/99
> 02:18 PM ---------------------------
>
>
> Xu He <xuhe@YAHOO.COM> on 04/16/99 11:57:53 AM
>
> Please respond to Discussion of IBM NetView and
> POLYCENTER Manager on
> NetView <NV-L@UCSBVM.UCSB.EDU>
>
> To: NV-L@UCSBVM.UCSB.EDU
> cc: (bcc: Leslie Clark/Southfield/IBM)
> Subject: Re: Routers that appears twice
>
>
>
>
>
> Yes, we see this at our locations a lot. For us,
> it's a problem with
> the DNS, for some strange reason, the WAN people at
> my client site
> decided to give a DNS name for each interface on the
> router. It's not
> too briliant of an idea, but it's something i have
> to live with.
> During the initial discovery ping sweep, it sees the
> address and
> resolve a name to the address. Since there are
> multiple DNS entries
> associated with the same router, it creates two
> entries in the map.
>
> What I ended up doing is delete both entry, put the
> ip address of the
> interface I care about in the netmon.seed. Once I
> discovered the
> correct one, I demand poll it and most of the time
> it will generate a
> correct symbol. It's a painstaking process.
>
> Hope this helps.
> Xu He
>
> --- Adrian Cappelletti <Adrian@TECNET.COM.AR> wrote:
> > Hi all,
> >
> > Did it happen that 1 router appears twice in the
> > same level of submap?. I mean: Suposse that you
> have
> > a router with 4 interfaces. The situation is that
> in
> > one symbol you see 2 interfaces and in a second
> > symbol you see the others 2. But, all interfaces
> > belong to a one router.
> >
> > Did anybody suffer something like this ?
> >
> > Thanks in advance.
> >
> > Adrian
> >
> >
> >
>
> ===
> Xu He
> Network Engineer
> Network Solutions, Inc
> _________________________________________________________
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