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ROUTERS2.DOC -- 19980322 -- Email thread on Routers and NetWare routing
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Date: Thu, 15 Jan 1998 07:15:35 CDT
From: "Elbert LaGrew [Telecom Manager]" <lagrew@MDH-ADMIN.HEALTH.STATE.MN.US>
Subject: Re: Server not appearing in rconsole

>>Why would a server appear in slist and in most other respects seem to
>>be ok, but not appear in the list of servers available to rconsole?
>
>Is there a router between the servers?
>
>I've seen that happen when a router was dropping packets during SAP
>updates.
>
>Solution is to tweak the SAP and RIP management on the router, preferably
>changing from RIP to EIGRP if you have not already.
>
>Neil Price

Good answer!

Also, there may be an access list set on the router which may not be
allowing through SAP 107 from the server itself.

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Date: Tue, 20 Jan 1998 09:26:18 -0800
From: Donovan Bray <dbray@BASS.CUESTA.CC.CA.US>
Subject: Re: VLANs on NW 4.11

>Anyone got any experience implementing VLANs in a Netware 4.11
>Environment?

VLANS ARE complicated and VLANS are still VENDOR dependent. Meaning what
works for Cisco Vlans won't work for Cabletron, or 3com VLANS,...soon with
standards that are coming, maybe.

A good way too look at VLANS is that EACH VLAN is its own wire. Shared VLANS
don't make since, the only reason for creating a VLAN is for BROADCAST
Containment, why would you want to create two where one would do just fine.
Once you have VLANS you need the same components you would need for hooking
two different wires together. Namely a router. Again it depends on your
implementation, CISCO uses Layer 2 switches and Routers to get cross VLAN
traffic. On the Other hand Cabletron uses Layer 3 switches to accomplish the
same thing, but the IDEA is the same, to go accross the vlan requires
something look at the Network portion of the packet and act on it. (layer 3
switches incorporate enough router technology to move packets, but not
enough to make them useful as routers)

Now Cisco has a great VLAN technology, they have created a protocol called
ISL that allows VLAN traffic to travel over a single link, which includes
router connections, and with the addition of an ISL card, servers can be put
directly on multiple VLANS (The Servers actually see a different NIC for
each vlan). ( Most other vendors only support VLAN traffic trunked between
switches)

If you are dealing with a vendor that doesn't support that kind of trunking
this is what your network would look like. Assuming you aren't using a layer
3 switch.

	      ROUTER
	      |    |
	  INF-A    INF-B
	      |    |
	      SWITCH
	    /  |  |  \
	   SA  SB WA  WB

WA: Workstation A is on VLAN A, If it sends a packet to SERVER A then it
will be directly forwarded by the switch.

WB: Workstation B is on VLAN B, If it sends a packet to SERVER A then it
will be forwarded to the router Interface B (INF-B). The router will then
make a determination and forward it to the server on VLAN A via Interface
INF-A.  Remember though a router doesnt make a determination on VLAN, it
will make it on the Network Data. So if your talking IP you better have a
valid IP Network, Vlan A would be on a different subnet than VLAN B. If your
talking IPX/SPX you have to have valid External Netnumbers for the
encapsulations your using, VLAN A would be a different network than VLAN B.

What if I want a server on both vlans. For Netware Servers put in another
NIC and configure it properly, and it becomes a router. IF SA and SB went to
different nics on the same server then you would need to deal with all the
SAP issues because now your going to have the network advertising the same
server name with two different paths. (I've never done this with netware, I
have done it with an NT Server with IP only, set to no ip forward, I would
assume that you block the sap advertisements on the router for the SA-SB
Server, allowing each vlan to recieve only the native sap broadcast.)

We are currently running Netware on a Cisco Switched network with ISL. We
evaluated Cabletron, 3COM, and Bay Networks solutions as well, but we chose
Cisco because of their Robust VLAN Support. There have been some caveats,
but we can discuss those at a later date if you are interested. The bottom
line is if you treat each VLAN as a separate wire your on the right track,
theres no magic, and it doesn't make networking simpler, but it does give
you more options and thats why its valuable.

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Date: Sun, 22 Mar 1998 22:35:32 -0500
From: Darwin Collins <nov-list@DART.ORG>
Subject: Re: Router Mystery

>Do routers work with a specific frame type for IPX?

No.  They should work with all frame types of IPX.  However, we have
seen some Bay Network 'Clams' that will only work correctly with small
networks and the 802.2 frame type.

>Do the routers 'learn' the network address by listening to the network,
>or are they hard coded when the router is configured.

It depends.  You can use Static (hard coded) or Dynamic or Both settings.
I believe you can use IPXCON (on the server console) to help diagnose
the problem.

>Is it possible I was fibbed to about these boxes moving IPX?

Perhaps they hardcoded them, and did not set 'all' the numbers in.

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