[tforum] Re: Hub Paradise Project - General Deployment

Pete Kruckenberg pete@uen.org
Fri, 3 Aug 2001 11:47:00 -0600 (MDT)


'ip default-network' is used only to tag a route in EIGRP as
the default network candidate. This will typically occur on
only a few (core) routers, which will propogate that route
out through the network. If a router is not directly
connected to the defined default-network, that statement
means nothing anyways. The main reason for removing it is
that it can cause problems, so we're safer without it.

In some cases 'ip default-gateway' is necessary to do remote
IOS upgrades from outside the local LAN. Routers such as the
Cisco 1000 and 2500 series that run IOS from flash (instead
of loading it from flash into RAM like 3600 and 7000+ series
do) must boot into monitor mode to update IOS.  When they
are in monitor mode, they act like a host instead of a
router, and will use the default-gateway to reach the update
server (TFTP) if it isn't on the local network. We will
leave ip default-gateway in the routers.

Pete.

On Fri, 3 Aug 2001, Stephen Chipman wrote:

> I was under the impression the "ip default-network"
> command was needed to do remote IOS upgrades?
>
> Steve
>   ----- Original Message -----
>   From: Tony Bueno
>   To: tforum@uen.org ; Outage ; UEN Technical Staff Mail List
>   Cc: Jamie Fowers ; Wes Ferguson ; Kelly Genessey ; Geoff Slater ; Scott Richardson ; Mike Downie ; Paul Symonds ; Steve Smith ; Dave Devey ; Bob Giles ; Bob Slater ; Brad Miller ; Dave Johnson ; Gaylen Williams ; Jeff Egly ; Jeff Short ; Joel Young ; Steve Chipman
>   Sent: Friday, August 03, 2001 7:55 AM
>   Subject: Hub Paradise Project - General Deployment
>
>
>   Hi:
>
>   The following is another in a series of new initiatives by the UEN Engineering and Operations Departments to standardize our router configurations and enhance system performance.  The information below was provided during the "Hub Paradise" trial in the USU Hub area by Pete Kruckenberg and has been adapted for this general deployment announcement...
>
>   The next installment of the UEN Hub Paradise project will start Tuesday August 7, 2001 at 6:00PM (detailed schedule is included below). There is a potential it will break some sites or groups of users.  I realize that is short notice, but we would like to squeeze this change in before school starts.
>
>   In this pilot, we will be using some of the capabilities we have now that we are a classless IP network. This means we can reduce route table sizes by aggregating multiple route announcements into a single "super announcement".
>
>   This focus of this initiative will be on reducing route table sizes at the edge devices, at the hub, and from the hub to the UEN core. In the USU pilot conducted earlier this week Pete projected a 60-95% reduction in the size of routing tables at the edge.  The measured benefit after the changes were implemented was a reduction in routing table size of approx. 90% (from 155 to 13 routes).  With smaller routing tables, this will also reduce router memory requirements.
>
>   From the hub to the edge devices, we will be limiting routes sent to just the 'default' routes. We will also be removing the 'ip default-network' statement from the router, as the default network is already tagged in the routing protocol and the configuration command is unnecessary. This will not interfere with intra-district routing or district/hub redundancy routing (in fact, it'll make it easier to do).
>
>   While we have spent an inordinate amount of time checking and re-checking our planned changes, it is possible that we might mess something up on this test. That's why we're starting at 6:00PM, to give plenty of time to check connectivity after the changes are made. And, as usual, we will be available Tuesday to work on specific problems that might crop up or after hours on the NOC on-call pager.
>
>   Possible problems would present themselves in an entire site or an entire block of servers/users (within the same address block) not being able to get to the Internet or UEN services, or be reachable from the Internet and UEN. Problems should be very obvious (which is good and bad).
>
>   When problems are reported, we need to know the IP addresses of the user and the site they are trying to reach to diagnose the problem. Report all problems to the NOC at 801-585-7440.
>
>   All changes should be complete by 10:00PM, if you'd like to get a head-start on checking things before the start of business the following day. If there are specific checks you would like us to run, send me an email with a list of the sites and services and we will check them for you. We will on a district-by-district basis following the implementation of these changes report on the impact to sites within each district we used as performance benchmarks.  If you would like us to evaulate the impact on a speecific site within your district, please forward that information to me.
>
>   There are no specific changes necessary for you to make on elementary school routers.
>
>   General Deployment Schedule:
>   Dixie/NUES/CEU - Tuesday August 7th
>   DATC/UVSC - Wednesday August 8th
>   SLCC - Thursday August 9th
>   SUU/Snow/Snow South - Friday August 10th
>   San Juan/Moab/Roosevelt - Monday August 13th
>
>   6:00 P.M. Apply distribute list changes to core and hub devices
>   3:00 A.M the following day CiscoWorks will apply the following clean-up changes to edge devices in the respective hub area and exceptions cleaned up manually by 9:00 a.m.
>
>   Router Clean-up Changes:
>   Security issues:
>    no service udp-small-servers
>    no service tcp-small-servers
>    no ip http server
>    no ip finger
>
>   Network:
>    no ip default-network 205.124.253.0
>    (some default-networks are different IP's, and will have to
>    be cleaned up manually)
>
>    router eigrp 205
>     no auto-summary
>
>
>   As always, call me or email with your questions or concerns.
>
>
>   Tony
>
>   Tony Bueno
>   NOC Manager
>   Utah Education Network
>   Office: 801-585-7406
>   Cell:  801-558-4453
>   Pager: 801-249-6345
>   mailto:tony@uen.org
>