HDTenEightyP/NetNews huggingface dataset:
From: Hank Nussbacher <HANK@VM.BIU.AC.IL>
Subject: Subnetting and class B nets
X-Delivery-Notice: SMTP MAIL FROM does not correspond to sender.
Date: 27 Aug 92 16:09:37 IST

    I am sure someone has already solved this problem since it seems
like a very  common problem.  Suppose  you have one  class B address
(i.e.  132.64.x.x)  and  have   about  120  small  units   scattered
throughout the USA with each around 20-30 systems connected.  Now in
order to interconnect all these  subnets of 132.64.x.x we use  cisco
routers with many lines.   We want to use  the same class B  net for
the  lines  and  not  some  other  network,  since  that would break
subnetting rules (you  are not allowed  to seperate two  segments of
the same class B via a segment of some other class C or B network).

    So we choose a subnet  mask of 255.255.255.0 for the  individual
units  and  for  the  lines  we  would  like  to  use something like
255.255.255.248.  This  way we  get greater  efficient use  from the
address space, rather than wasting an entire 256 address range space
for each leased line.  If we have 120 lines, we could end up wasting
132.64.1.x-132.64.120.x leaving just about 50% of the address  space
for real work.  Packing the addresses for the leased lines into  one
segment of the class B network - such as 132.64.1.x makes sense  and
should work.  But  for some reason  (perhaps some subnetting  rule),
the cisco will  to not accept  two *different* subnet  masks for the
same class B  network.  The cisco  automatically changes the  subnet
mask for all interfaces with the same class B network address to the
last subnet mask of the last interface set.

I am sure there must be some config command to bypass this problem.
Or is everyone wasting oodles of address space on their leased line
subnets?

Thanks,
Hank Nussbacher
Newsgroups: comp.dcom.sys.cisco
From: joer@inca.law.csuohio.edu (Joe Rosenfeld)
Subject: Is there such as thing as a Terminal server that does tn3270?
Organization: Cleveland State University
Date: Fri, 4 Sep 1992 01:08:42 GMT

This may be a silly question, and if so, I apologize in advance.

Someone told me that Cisco makes a terminal server that will do tn3270, so 
that a 3270 terminal may be connected to a terminal server and use tn3270 to 
access an IBM mainframe host.

Can anyone substantiate this?  I would really like to know.  Feel free to 
email me at: joer@inca.law.csuohio.edu.

thanks in advance for your assistance.

Regards-
Joe

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Joe Rosenfeld
joer@inca.law.csuohio.edu
From: kapffer@Informatik.Mathematik.Uni-Mainz.DE (Matthias Kapffer)
Newsgroups: comp.dcom.sys.cisco
Subject: 8.3(5) release notes ?
Date: 1 Sep 92 16:35:05 GMT
Organization: Computer Science, Johannes Gutenberg-Universitaet

I've just seen that the 8.3(5) software revision is available on ftp.cisco.com,
but the accompaning release notes (file gsr_83.psf) is still at 8.3(3).

Is there any chance that this will change ?

						- Matthias Kapffer
Newsgroups: comp.dcom.sys.cisco
From: David Hampton <hampton@cisco.com>
Subject: Re: Banyan services on non-serverless networks 
Date: 03 Sep 92 19:33:10 PDT

> If you have a network connected to a cisco system with Vines routing
> enabled with PCs and a Banyan server on this network, but you do *not*
> flag the network serverless, can the PCs obtain services such as getting
> the time from other servers across the cisco, or are they restricted to
> obtaining these services from the local server (this is what we want)?

If you do not flag a network as "serverless" the router will not
helper any zero hop broadcasts frames.  This should effectively stop
things like the time service that function with zero hop broadcast
messages.

David

+-------------------------------------------------------+
| David R. Hampton      \     email:  hampton@cisco.com |
| cisco Systems, Inc.    \                              |
| 1525 O'Brien Ave        \     Phone:  +1 415.326.1941 |
| Menlo Park, CA 94025     \      Fax:  +1 415.688.8282 |
+-------------------------------------------------------+
From: trentf@ultra.com (Trent Fierro)
Newsgroups: comp.dcom.sys.cisco
Subject: Anyone selling a MEC 6?
Keywords: AGS+/Cbus card
Date: 3 Sep 92 23:38:17 GMT
Reply-To: trentf@ultra.com ()
Distribution: usa
Organization: Ultra Network Technologies


If anyone has a used MEC 6 that they are willing to part with
in the next few weeks, please get back to me ASAP. Call with
expected price and date in which it can be shipped.

Thanks in advance,
trent

-- 
***********************************************************************
Trent Fierro          trentf@ultra.com       	 Voice:  (408) 922-0100 
UltraNetwork Technologies ...!ames!ultra!trentf  FAX  :  (408) 433-9287 
101 Daggett Drive         			 San Jose, CA 95134
From: hedrick@athos.rutgers.edu (Charles Hedrick)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: Is there such as thing as a Terminal server that does tn3270?
Date: 4 Sep 92 02:42:55 GMT
Organization: Rutgers Univ., New Brunswick, N.J.

joer@inca.law.csuohio.edu (Joe Rosenfeld) writes:

>Someone told me that Cisco makes a terminal server that will do tn3270, so 
>that a 3270 terminal may be connected to a terminal server and use tn3270 to 
>access an IBM mainframe host.

As far as I know, Cisco terminal servers support only asynch, ASCII
terminals.  They use tn3270, but what you get is a 3270 emulator
designed for use with ASCII terminals.  I don't know of any Cisco
product that will connect to real 3270's.  We're using tn3270 for
access to our IBM systems.  People seem to like it.  It is based on
the Berkeley implementation, complete with termcap.  You have to put
the termcap entries into the Cisco configuration file.
Newsgroups: comp.dcom.sys.cisco
From: dberry@csa.cs.technion.ac.il (dberry)
Subject: Modeling CISCO routers in networks simulation
Organization: Technion, Israel Inst. of Technology
Date: Thu, 3 Sep 1992 12:45:42 GMT
Keywords: network planning, network simulation, modeling Cisco routers

I have been assigned the job of designing a network. The customer requires
that I simulate the alternative topologies and show the merits of the 
topology of choice under various workloads which are typical to the 
customer's network. I have a library with various LAN protocols as well
as X.25 for the WAN. I have repeaters and bridges algorithms (in a
reasonable detail, those are not queuing systems with M/M/n to G/G/k
type distributions) but I do not have routers algorithms, specifically I do
not have a detailed model of Cisco routers (which is what the customer
have). I would like to ask for help from people who evaluated the
performance of various networks using Cisco routers, where the level of
detail in the simulation is, as I described, a level of data forwarding and
data processing algorithms and not a higher level of abstraction of 
interconnection points.

Thanks, Orna



-- 
Prof. Daniel M. Berry, Computer Science Department, Technion, Haifa 32000 ISRAEL
Tel:+972-4-294325, Bitnet:DBERRY@TECHSEL
Csnet & Internet:dberry@sel.technion.ac.il
Newsgroups: comp.dcom.sys.cisco
From: marchal@europe.cisco.com (Marie Marchal)
Subject: Cisco NetWorkers Symposium
Date: 31 Aug 92 16:25:05 BST
X-Mailer: ELM [version 2.3 PL11]

Cisco Systems Europe will be holding the third annual NetWorkers Europe
from September 14 - 16, Muenchen Park Hilton, Muenchen.

This is an opportunity for Cisco customers to learn about new Cisco
products; discuss technology issues with Cisco engineers, product
marketing managers, and executives; and, provide Cisco with product
requirements.

In-depth technical sessions will be held on the following topics:
SNA Integration, WAN, FDDI, OSI, Designing Global Networks, Broadband/ATM,
and SNMP Management.  Additionally, a Round Table session will be
held to discuss topics of importance to senior managers.

Cisco is pleased to provide the following to all conference attendees:
breakfast and lunch all three conference days
welcome reception Sunday evening, September 13
gala dinner Monday evening, September 14
city tour with refreshments Tuesday evening, September 15 
all meeting materials

NetWorkers attendees are responsible for transportation and hotel
accommodations.  There is no registration fee for this conference.

Cisco customers are invited to register for NetWorkers 92 Europe
by contacting Les Lignes Amarantes, phone +32 (2) 648 1606.
From: tli@cisco.com (Tony Li)
Newsgroups: comp.dcom.sys.cisco
Subject: RIP hostroutes
Date: 26 Aug 92 23:34:38 GMT


   i have seen a strange behavior on one of our AGS+ ciscos. Another host is
   announcing the hostroute of his primary interface on the 2nd ethernet with
   RIP. The AGS+ sees the RIP packet and installs a route to the whole subnet
   through the other host.
   So the questions are:
   Does the AGS+ simply ignore the hostpart of the address?

Yes.

   Is there a way to change this behavior?

No.

   Does this still happen in 8.3 and 9.0? (We are currently using 8.2(6).)

Yes.  It will change in release 9.1.

Tony
From: pace@tabarzin.usace.mil (Joe Pace)
Newsgroups: comp.dcom.sys.cisco
Subject: How much do extended access lists degrade performance?
Date: 3 Sep 92 21:46:04 GMT
Organization: US Army Corps of Engineers, Sacramento District


Has anyone had experience with long extended access lists on Cisco AGS+'s
and would have an idea of how much this sort of activity degrades
routing performance?  Does it severely degrade performance when
filtering on cBus devices, such as the FDDI or MEC-6 cards?  Does
filtering reduce the effective bandwidth to less than 150 Mb/s by 
involving the CPU, or is filtering performed on the MEC-6 cards or
in the cBus controller?

Thanks

Joe Pace
-- 
-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Joe Pace                                              UNIX/Networking Analyst
US Army Corps of Engineers                                     pace@usace.mil
Sacramento District                                     JPPACE@UCDAVIS.BITNET
Newsgroups: comp.dcom.sys.cisco
From: hyder@niwot.scd.ucar.EDU
Subject: Re: bug in 9.0(1) ? 
Date: 31 Aug 92 11:03:01 -0600

>> Recently we discovered strange behaviour in 9.0(1).
>> We route tcp/ip decnet and appletalk and bridge LAT in a 
>> newly installed MGR. 
>> ARP requests done on lan-s connected to this router are
>> FORWARDED to all interfaces! Even worse, since they are
>> forwarded to a AGS with 8.3(3), the AGS has no way of
>> protecting himself, but instead the AGS will put the ARP-s
>> to all of hi's interfaces. In one case he substituded the
>> original ip-address with the AGS ip-address.
>> ...

We have also seen some very troubling ARP related problems in
9.0(1).  At this time we are using an ftp'd copy of 9.0(1.10)
that seems to solve the problems.  My advice would be if you use
bridging don't use 9.0(1).

Most of the nasty behavior seems to be related to the unexpected 
behavior on the Cisco routers related to the handling of ARP >reply<
packets.  For the record the queries are broadcast and are filtered
>HOWEVER< replies are bridged, in our case to darn near everywhere on
the net. [Please see question below.]

What seemed to happen under 9.0(1) was that the bridged ARP reply
packets caused routers to install incorrect arp cache entries for
related routes.  For example an ARP reply for a host that was known
to be beyond another router caused an update of ALL arp cache entries
for that net PLUS it updated the cache entry for the router.  (Turns
off the router rather nicely.)  Rogue hosts, with the wrong IP address
for the cable segment in question, absolutely triggered this arp cache
corruption.

My questions for everyone out there are:

   Why should these response packets be bridged to everyhwere?

	Yes, they truly are not IP packets by definition and are
	bridge-able.  However, from what I can see on the tcpdumps
	the destination host's location is well known, so it seems to
	me that bridging these off of the origin segment is almost
	never correct.  Is this a feature or is it done for some reason?

   Is the solution to this to install a filter that stops all bridged
   arp packets?  Does this stop anything else I'm likely to need?
   (Like my AppleTalk)

As always thanks in advance.
	Paul Hyder
	NCAR
	Boulder,CO
From: Tom_Karolyshyn@dgc.mceo.dg.com
Subject: Re: Subnetting and class B nets
Date: 27 Aug 92 16:11:34 edt

X-Ceo_Options:  Document


CEO document contents:  

  > I am sure there must be some config command to bypass this problem.
  > Or is everyone wasting oodles of address space on their leased line
  > subnets?


You can use the ip-unnumbered feature to conserve addresses, if your routers
are all ciscos and if ip-unnumbered suits your needs.  If you can afford to
wait, you can eventually use OSPF or RIP II, though I have no comment on either
their availability or stability.

We use the following scheme to "conserve" subnets on a lot of our
point-to-point serial links today.

What we've done is to set aside a couple of subnets dedicated to serial links.
These subnets will ultimately become "invisible" to the rest of the network.
The number of subnets you need to allocate depends on the maximum number of
serial links per router.  This is because you don't want to (or can't)
duplicate subnet numbers per router.

We use a standard subnetted class B network mask, 255.255.255.0 across our
entire network.  What we do on the serial links is duplicate the same subnet on
each serial link, with the host portion of the IP address unique for various
reasons.
For example, 
                   Router A       56k         Router B
                 128.221.183.5-----------128.221.183.105

                   Router C       56k         Router D
                128.221.183.15-----------128.221.183.115

Note that only one subnet was used for 2 completely separate serial links.
This subnet is utilized again and again...

The key to getting this to work is to prevent these "invisible" (actually
duplicate) subnets from getting into the outgoing routing updates.  Use the
"distribute-list out" command and access-lists (or equivalent) to keep these
subnets out of the RIP or IGRP routing updates.  The mindset here is that these
serial links are only there to gateway you to another subnet, i.e., your
ultimate destination.  Therefore the subnet's existence only needs to be known
and is only used by the adjacent router.

This works out quite well.  From a global network view, you get the same effect
as an ip-unnumbered interface, i.e., can't "see" (ping, etc.) the interface
from just anywhere anymore.  But you can still actually ping the serial
interface, if necessary, from the router directly connected to the other end of
the serial link.

There are some side issues related to SNMP traps, etc., which is one of the
reasons for unique host ids.  (nothing which hasn't been worked around :-)

Tom

Tom Karolyshyn
Data General Corp
Westboro, MA 01580
508-870-7936
From: brunke@dkrz-hamburg.dbp.de (Lutz Brunke)
Newsgroups: comp.dcom.sys.cisco
Subject: RIP hostroutes
Date: 26 Aug 92 14:29:10 GMT
Reply-To: brunke@dkrz-hamburg.dbp.de
Organization: Deutsches Klimarechenzentrum GmbH, Hamburg

High,

i have seen a strange behavior on one of our AGS+ ciscos. Another host is
announcing the hostroute of his primary interface on the 2nd ethernet with
RIP. The AGS+ sees the RIP packet and installs a route to the whole subnet
through the other host.
So the questions are:
Does the AGS+ simply ignore the hostpart of the address?
Is there a way to change this behavior?
Does this still happen in 8.3 and 9.0? (We are currently using 8.2(6).)

Thanks in advance,
Lutz
Newsgroups: comp.dcom.sys.cisco
From: peter@goshawk.lanl.gov
Subject: Re: Subnetting and class B nets 
             <CMM.0.90.2.714935295.vaf@Valinor.Stanford.EDU> 
Date: 27 Aug 92 22:04:49 MST


Sounds like a good gap for network 127 to fill ...


peter
Newsgroups: comp.dcom.sys.cisco
From: Pasha Quadri <quadri@last-call.cisco.com>
Subject: Re: X.25 line utilization???
Date: 28 Aug 92 13:27:32 PDT

> 
> Hi,
> 
> I have some statistics I have been gathering from one of my packet
> switch nodes within my company's private X.25 network.  I have been
> monitoring the incoming and outgoing bit/sec data rates between
> Richardson Texas and Stockholm Sweden.
> 
> We have a full duplex communications link capable of 112
> kilobits/sec of data throughput.  We have recently gotten into a
> quarrel over what the utilization of the link is.  
> 
> Here is the scenario.  My statistics tell me that I have the
> following:
> 
> 40,000 bits/sec input data rate
> 60,000 bits/sec output data rate
> 
> I think that the utilization of our line during this time (expressed
> as a percentage) is ((40,000 + 60,000)/112000) * 100%
> 
> while some others here think that the utilization of our line
> (expressed as a percentage) is gotten by taking the higher of the
> two data rate figures and dividing that by the maximum data rate, or
> (60,000/112000)*100%.
> 
> Does anyone have any input on which is the right way to express the
> utilization of our link?  Any input would be appreciated.
> 
> Blake Holman
> Ericsson Network Systems, Inc.
> Richardson, Texas
> (214) 997-6784
> 


Hello Blake,

Since serial lines are full duplex dividing by the bandwidth of the link
will just not work. Hence greater of either input OR output bytes, bits, or
packets per second be taken and divided by the BW of the link.

One of our Engineers had written an article on this and a formula for
average utilization was :

 average utilization = [(bytes-input OR bytes-output) * 8] / ifSpeed

   The OR above denotes a case where you should take the larger
of the input and output values to divide by the bandwidth (ifSpeed) to
determine the true link utilization.

Hope this helps.


Regards

Pasha Quadri
cisco Cust.Engg
Newsgroups: comp.dcom.sys.cisco
From: Robert Elz <kre@munnari.oz.au>
Subject: Re: Subnetting and class B nets 
             <2299*merdian@rus.uni-stuttgart.dbp.de> 
Date: 28 Aug 92 01:35:35 +1000

    Date:        27 Aug 92 16:36:57+0200
    From:        Peter Merdian <merdian@rus.uni-stuttgart.dbp.de>
    Message-ID:  <2299*merdian@rus.uni-stuttgart.dbp.de>

    According to RFC 950 only one subnetmask is allowed for an IP network:

I don't think this is true - RFC950 is not highly clear on
the point, but it does seem to suggest that different masks
on different interfaces is possible - and it never says that
that should only happen if the different interfaces are on
different nets.

The problem was never really the spec, but the implementations,
which with any luck will be gradually getting fixed.

Not only does OSPF transport subnet masks around, so does
RIP-II.  I'd assume that anything RIP can do IGRP will have
to do too...

kre
Newsgroups: comp.dcom.sys.cisco
From: Sam Wilson <ercm20@festival.ed.ac.uk>
Subject: Test
Reply-To: Sam.Wilson@edinburgh.ac.uk
Date: 01 Sep 92 14:05:19 BST
Via: uk.ac.edinburgh.festival; Tue, 1 Sep 1992 14:05:22 +0100

Test message to check mail to Germany via UK Cisco mailing list.  Please
ignore. 

Sam Wilson                              aka cisco-request@mailbase.ac.uk
Network Services Division
Computing Services, The University of Edinburgh
Edinburgh, Scotland, UK
From: chuckc@cobalt.corp.sgi.com (Chuck Clay)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: RIP hostroutes
Date: 27 Aug 92 01:22:46 GMT
       "RIP hostroutes" (Aug 26,  4:34pm)
X-Mailer: Z-Mail (2.0.5 1/15/92)

On Aug 26,  4:34pm, Tony Li wrote:
> Subject: RIP hostroutes
> 
>    i have seen a strange behavior on one of our AGS+ ciscos. Another host
is
>    announcing the hostroute of his primary interface on the 2nd ethernet
with
>    RIP. The AGS+ sees the RIP packet and installs a route to the whole
subnet
>    through the other host.
>    So the questions are:
>    Does the AGS+ simply ignore the hostpart of the address?
> 
> Yes.
> 
>    Is there a way to change this behavior?
> 
> No.
> 
>    Does this still happen in 8.3 and 9.0? (We are currently using
8.2(6).)
> 
> Yes.  It will change in release 9.1.
> 
> Tony
> 

FYI, our 8.3(2.4) beta firmware doesn't try to convert a host
route into a network one.  We noticed this when a host route
got loose on our backbone and trashed the corresponding network
route on every cisco we had except the one running 8.3(2.4). Yuck.

Chuck Clay
chuckc@sgi.com
Newsgroups: comp.dcom.sys.cisco
From: "Michael (NMI) Dorl" <DORL@macc.wisc.edu>
Subject: Cisco IP Accounting
Date: 31 Aug 92 16:54 CDT
X-Vms-To: IN%"CISCO@SPOT.COLORADO.EDU",DORL

The following message describes a problem we are facing.
If you have solved it with non-Cisco equipment, are
interested it it, or would like to see Cisco implement
the proposed changes, we'd like to hear from you.
 
WiscNet is a IP network serving Wisconsin colleges and
universities. Members are connected with Cisco routers.
Each member is connected through an ethernet interface
on some WiscNet provided cisco router. In general, the
Cisco provided traffic statistics for these ethernet
interfaces provide excellent information on traffic
to/from the members. Some members have extended the
network to non-members through connections we call
backdoors. WiscNet has a need to measure this backdoor
traffic on a network by network basis.
 
Although Cisco does provide some IP accounting, it is
not suitable for this need because...
 
  The information gathered is too detailed.  You can
  select which networks to do accounting for with a
  access list but once selected, the router does
  accounting on a source destination IP pair basis.
  Thus separate accounting entries are kept for
  potentially hundreds or thousands of IP
  source/destination pairs.
 
  Only packets flowing out are accounted for.  Thus to
  get a total picture for a given network number, one
  must enable accounting on all interfaces on a router.
 
What we'd like to see might be effected by a change to
the IP ACCOUNTING-LIST command.
 
  IP ACCOUNTING ip-address mask keywords
 
where keywords could be
 
  SUMMARY
 
    make a single summary entry for matching packets.
 
  IN
 
    include incoming packets
 
  OUT
 
    include outgoing packets
 
SUMMARY accounting entries have the ip-address (from the
IP ACCOUNTING-LIST command) in either the source or
destination address and zero in the other address.
 
This would allow one to measure traffic to/from specified
networks while using only two accounting entries
minimizing search time and buffer resources.   It would
also allow all accounting for a network to be done on a
single interface rather than router wide.
 
Michael Dorl              (608) 262-0466  fax (608) 262-4679
dorl@vms.macc.wisc.edu    MACC / University of Wisconsin - Madison
dorl@wiscmacc.bitnet      1210 W. Dayton St. / Madison, WI 53706